1
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Vidal LEL, Figueira-Mansur J, Jurgilas PB, Argondizzo APC, Pestana CP, Martins FO, da Silva Junior HC, Miguez M, Loureiro BO, Marques CDFS, Trinta KS, da Silva LBR, de Mello MB, da Silva ED, Bastos RC, Esteves G. Process development and characterization of recombinant nucleocapsid protein for its application on COVID-19 diagnosis. Protein Expr Purif 2023; 207:106263. [PMID: 36921810 PMCID: PMC10012136 DOI: 10.1016/j.pep.2023.106263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/10/2023] [Indexed: 03/15/2023]
Abstract
COVID-19 pandemic was caused by the severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2). The nucleocapsid (N) protein from Sars-CoV-2 is a highly immunogenic antigen and responsible for genome packing. Serological assays are important tools to detect previous exposure to SARS-CoV-2, complement epidemiological studies, vaccine evaluation and also in COVID-19 surveillance. SARS-CoV-2 N (r2N) protein was produced in Escherichia coli, characterized, and the immunological performance was evaluated by enzyme-linked immunosorbent assay (ELISA) and beads-based array immunoassay. r2N protein oligomers were evidenced when it is associated to nucleic acid. Benzonase treatment reduced host nucleic acid associated to r2N protein, but crosslinking assay still demonstrates the presence of higher-order oligomers. Nevertheless, after RNase treatment the higher-order oligomers reduced, and dimer form increased, suggesting RNA contributes to the oligomer formation. Structural analysis revealed nucleic acid did not interfere with the thermal stability of the recombinant protein. Interestingly, nucleic acid was able to prevent r2N protein aggregation even with increasing temperature while the protein benzonase treated begin aggregation process above 55 °C. In immunological characterization, ELISA performed with 233 serum samples presented a sensitivity of 97.44% (95% Confidence Interval, CI, 91.04%, 99.69%) and a specificity of 98.71% (95% CI, 95.42%, 99.84%) while beads-based array immunoassay carried out with 217 samples showed 100% sensitivity and 98.6% specificity. The results exhibited an excellent immunological performance of r2N protein in serologic assays showing that, even in presence of nucleic acid, it can be used as a component of an immunoassay for the sensitive and specific detection of SARS-CoV-2 antibodies.
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Affiliation(s)
- Luãnna Elisa Liebscher Vidal
- Macromolecules Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil.
| | - Janaina Figueira-Mansur
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Patrícia Barbosa Jurgilas
- Macromolecules Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Ana Paula Correa Argondizzo
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Cristiane Pinheiro Pestana
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Fernanda Otaviano Martins
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Haroldo Cid da Silva Junior
- Immunological Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Mariana Miguez
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Bernardo Oliveira Loureiro
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Christiane de Fátima Silva Marques
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Karen Soares Trinta
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Leila Botelho Rodrigues da Silva
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Marcelle Bral de Mello
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Edimilson Domingos da Silva
- Diagnostic Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Renata Chagas Bastos
- Macromolecules Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
| | - Gabriela Esteves
- Recombinant Technology Laboratory, Institute of Technology in Immunobiologicals (Bio-Manguinhos), Fundação Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, 21040-900, Brazil
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2
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Morse M, Sefcikova J, Rouzina I, Beuning PJ, Williams M. Structural domains of SARS-CoV-2 nucleocapsid protein coordinate to compact long nucleic acid substrates. Nucleic Acids Res 2022; 51:290-303. [PMID: 36533523 PMCID: PMC9841419 DOI: 10.1093/nar/gkac1179] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/28/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
The SARS-CoV-2 nucleocapsid (N) protein performs several functions including binding, compacting, and packaging the ∼30 kb viral genome into the viral particle. N protein consists of two ordered domains, with the N terminal domain (NTD) primarily associated with RNA binding and the C terminal domain (CTD) primarily associated with dimerization/oligomerization, and three intrinsically disordered regions, an N-arm, a C-tail, and a linker that connects the NTD and CTD. We utilize an optical tweezers system to isolate a long single-stranded nucleic acid substrate to measure directly the binding and packaging function of N protein at a single molecule level in real time. We find that N protein binds the nucleic acid substrate with high affinity before oligomerizing and forming a highly compact structure. By comparing the activities of truncated protein variants missing the NTD, CTD, and/or linker, we attribute specific steps in this process to the structural domains of N protein, with the NTD driving initial binding to the substrate and ensuring high localized protein density that triggers interprotein interactions mediated by the CTD, which forms a compact and stable protein-nucleic acid complex suitable for packaging into the virion.
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Affiliation(s)
- Michael Morse
- Department of Physics, Northeastern University, Boston, MA, USA
| | - Jana Sefcikova
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Ioulia Rouzina
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH, USA
| | - Penny J Beuning
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Mark C Williams
- To whom correspondence should be addressed. Tel: +1 617 373 5705;
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3
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Zhang B, Xie Y, Lan Z, Li D, Tian J, Zhang Q, Tian H, Yang J, Zhou X, Qiu S, Lu K, Liu Y. SARS-CoV-2 Nucleocapsid Protein Has DNA-Melting and Strand-Annealing Activities With Different Properties From SARS-CoV-2 Nsp13. Front Microbiol 2022; 13:851202. [PMID: 35935242 PMCID: PMC9354549 DOI: 10.3389/fmicb.2022.851202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 06/13/2022] [Indexed: 11/25/2022] Open
Abstract
Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread throughout the world and has had a devastating impact on health and economy. The biochemical characterization of SARS-CoV-2 proteins is important for drug design and development. In this study, we discovered that the SARS-CoV-2 nucleocapsid protein can melt double-stranded DNA (dsDNA) in the 5′-3′ direction, similar to SARS-CoV-2 nonstructural protein 13. However, the unwinding activity of SARS-CoV-2 nucleocapsid protein was found to be more than 22 times weaker than that of SARS-CoV-2 nonstructural protein 13, and the melting process was independent of nucleoside triphosphates and Mg2+. Interestingly, at low concentrations, the SARS-CoV-2 nucleocapsid protein exhibited a stronger annealing activity than SARS-CoV-2 nonstructural protein 13; however, at high concentrations, it promoted the melting of dsDNA. These findings have deepened our understanding of the SARS-CoV-2 nucleocapsid protein and will help provide novel insights into antiviral drug development.
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Affiliation(s)
- Bo Zhang
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
- Bo Zhang,
| | - Yan Xie
- School of Public Health, Zunyi Medical University, Zunyi, China
| | - Zhaoling Lan
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Dayu Li
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Junjie Tian
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Qintao Zhang
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Hongji Tian
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Jiali Yang
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Xinnan Zhou
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
| | - Shuyi Qiu
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, China
| | - Keyu Lu
- College of Basic Medicine, Zunyi Medical University, Zunyi, China
- Keyu Lu,
| | - Yang Liu
- School of Public Health, Zunyi Medical University, Zunyi, China
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, China
- *Correspondence: Yang Liu,
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4
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Yu M, Zhang X, Zhang X, Zahra QUA, Huang Z, Chen Y, Song C, Song M, Jiang H, Luo Z, Lu Y. An electrochemical aptasensor with N protein binding aptamer-complementary oligonucleotide as probe for ultra-sensitive detection of COVID-19. Biosens Bioelectron 2022; 213:114436. [PMID: 35716641 PMCID: PMC9176179 DOI: 10.1016/j.bios.2022.114436] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/24/2022] [Accepted: 05/27/2022] [Indexed: 01/08/2023]
Abstract
The emergence of the COVID-19 epidemic has affected the lives of hundreds of millions of people globally. There is no doubt that the development of fast and sensitive detection methods is crucial while the worldwide effective vaccination programs are miles away from actualization. In this study, we have reported an electrochemical N protein aptamer sensor with complementary oligonucleotide as probe for the specific detection of COVID-19. The electrochemical aptasensor was prepared by fixing the double-stranded DNA hybrid obtained by the hybridization of N protein aptamer and its Fc-labeled complementary strand on the surface of a gold electrode. After incubation with the target, the aptamer dissociated from the labeled complementary DNA oligonucleotide hybrid to preferentially bind with N protein in the solution. The concentration of N protein was measured by detecting the changes in electrochemical current signals induced by the conformational transformation of the complementary DNA oligonucleotide left on the electrode surface. The sensor had a linear relationship between the logarithm of the N protein concentration from 10 fM to 100 nM (ΔIp = 0.098 log CN protein/fM - 0.08433, R2 = 0.99), and the detection limitation was 1 fM (S/N = 3). The electrochemical aptamer sensor was applied to test the spiked concentrations of throat swabs and blood samples from three volunteers, and the obtained results proved that the sensor has great potentials for the early detection of COVID-19 in patients.
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Affiliation(s)
- Mengdi Yu
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Xiaohui Zhang
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Xin Zhang
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Qurat Ul Ain Zahra
- Hefei National Lab for Physical Sciences at the Microscale and the Centers for Biomedical Engineering, University of Science and Technology of China, Hefei, 230026, PR China; Core Facility Center for Life Sciences, Department of Molecular Biology and Cell Biology, University of Sciences and Technology of China, Hefei, 230026, PR China
| | - Zenghui Huang
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Ying Chen
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Chunxia Song
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China
| | - Min Song
- Affiliated Hospital of Anhui Agricultural University, Hefei, 230036, PR China
| | - Hongjuan Jiang
- Affiliated Hospital of Anhui Agricultural University, Hefei, 230036, PR China
| | - Zhaofeng Luo
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027, PR China; The Cancer Hospital of the University of Chinese Academy of Sciences, Aptamer Selection Center, Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, 310022, PR China
| | - Ying Lu
- Department of Applied Chemistry, Key Laboratory of Agricultural Sensors, Ministry of Agriculture and Rural Affairs, Anhui Agricultural University, Hefei, 230036, PR China.
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5
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Ribeiro-Filho HV, Jara GE, Batista FAH, Schleder GR, Costa Tonoli CC, Soprano AS, Guimarães SL, Borges AC, Cassago A, Bajgelman MC, Marques RE, Trivella DBB, Franchini KG, Figueira ACM, Benedetti CE, Lopes-de-Oliveira PS. Structural dynamics of SARS-CoV-2 nucleocapsid protein induced by RNA binding. PLoS Comput Biol 2022; 18:e1010121. [PMID: 35551296 PMCID: PMC9129039 DOI: 10.1371/journal.pcbi.1010121] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 05/24/2022] [Accepted: 04/19/2022] [Indexed: 12/23/2022] Open
Abstract
The nucleocapsid (N) protein of the SARS-CoV-2 virus, the causal agent of COVID-19, is a multifunction phosphoprotein that plays critical roles in the virus life cycle, including transcription and packaging of the viral RNA. To play such diverse roles, the N protein has two globular RNA-binding modules, the N- (NTD) and C-terminal (CTD) domains, which are connected by an intrinsically disordered region. Despite the wealth of structural data available for the isolated NTD and CTD, how these domains are arranged in the full-length protein and how the oligomerization of N influences its RNA-binding activity remains largely unclear. Herein, using experimental data from electron microscopy and biochemical/biophysical techniques combined with molecular modeling and molecular dynamics simulations, we show that, in the absence of RNA, the N protein formed structurally dynamic dimers, with the NTD and CTD arranged in extended conformations. However, in the presence of RNA, the N protein assumed a more compact conformation where the NTD and CTD are packed together. We also provided an octameric model for the full-length N bound to RNA that is consistent with electron microscopy images of the N protein in the presence of RNA. Together, our results shed new light on the dynamics and higher-order oligomeric structure of this versatile protein. The nucleocapsid (N) protein of the SARS-CoV-2 virus plays an essential role in virus particle assembly as it specifically binds to and wraps the virus genomic RNA into a well-organized structure known as the ribonucleoprotein. Understanding how the N protein wraps around the virus RNA is critical for the development of strategies to inhibit virus assembly within host cells. One of the limitations regarding the molecular structure of the ribonucleoprotein, however, is that the N protein has several unstructured and mobile regions that preclude the resolution of its full atomic structure. Moreover, the N protein can form higher-order oligomers, both in the presence and absence of RNA. Here we employed computational methods, supported by experimental data, to simulate the N protein structural dynamics in the absence and presence of RNA. Our data suggest that the N protein forms structurally dynamic dimers in the absence of RNA, with its structured N- and C-terminal domains oriented in extended conformations. In the presence of RNA, however, the N protein assumes a more compact conformation. Our model for the oligomeric structure of the N protein bound to RNA helps to understand how N protein dimers interact to each other to form the ribonucleoprotein.
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Affiliation(s)
- Helder Veras Ribeiro-Filho
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Gabriel Ernesto Jara
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | | | - Gabriel Ravanhani Schleder
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Celisa Caldana Costa Tonoli
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Adriana Santos Soprano
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Samuel Leite Guimarães
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Antonio Carlos Borges
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Alexandre Cassago
- Brazilian Nanotechnology National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Marcio Chaim Bajgelman
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Rafael Elias Marques
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | | | - Kleber Gomes Franchini
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | | | - Celso Eduardo Benedetti
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- * E-mail: (CEB); (PSLO)
| | - Paulo Sergio Lopes-de-Oliveira
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- * E-mail: (CEB); (PSLO)
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6
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Dzuvor CKO, Tettey EL, Danquah MK. Aptamers as promising nanotheranostic tools in the COVID-19 pandemic era. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2022; 14:e1785. [PMID: 35238490 PMCID: PMC9111085 DOI: 10.1002/wnan.1785] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/02/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022]
Abstract
The emergence of SARS‐COV‐2, the causative agent of new coronavirus disease (COVID‐19) has become a pandemic threat. Early and precise detection of the virus is vital for effective diagnosis and treatment. Various testing kits and assays, including nucleic acid detection methods, antigen tests, serological tests, and enzyme‐linked immunosorbent assay (ELISA), have been implemented or are being explored to detect the virus and/or characterize cellular and antibody responses to the infection. However, these approaches have inherent drawbacks such as nonspecificity, high cost, are characterized by long turnaround times for test results, and can be labor‐intensive. Also, the circulating SARS‐COV‐2 variant of concerns, reduced antibody sensitivity and/or neutralization, and possible antibody‐dependent enhancement (ADE) have warranted the search for alternative potent therapeutics. Aptamers, which are single‐stranded oligonucleotides, generated artificially by SELEX (Evolution of Ligands by Exponential Enrichment) may offer the capacity to generate high‐affinity neutralizers and/or bioprobes for monitoring relevant SARS‐COV‐2 and COVID‐19 biomarkers. This article reviews and discusses the prospects of implementing aptamers for rapid point‐of‐care detection and treatment of SARS‐COV‐2. We highlight other SARS‐COV‐2 targets (N protein, spike protein stem‐helix), SELEX augmented with competition assays and in silico technologies for rapid discovery and isolation of theranostic aptamers against COVID‐19 and future pandemics. It further provides an overview on site‐specific bioconjugation approaches, customizable molecular scaffolding strategies, and nanotechnology platforms to engineer these aptamers into ultrapotent blockers, multivalent therapeutics, and vaccines to boost both humoral and cellular immunity against the virus. This article is categorized under:Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > Biosensing Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease
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Affiliation(s)
- Christian K O Dzuvor
- Bioengineering Laboratory, Department of Chemical and Biological Engineering, Monash University, Clayton, Victoria, Australia
| | | | - Michael K Danquah
- Department of Chemical Engineering, University of Tennessee, Chattanooga, Tennessee, USA
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7
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Caruso IP, dos Santos Almeida V, do Amaral MJ, de Andrade GC, de Araújo GR, de Araújo TS, de Azevedo JM, Barbosa GM, Bartkevihi L, Bezerra PR, dos Santos Cabral KM, de Lourenço IO, Malizia-Motta CL, de Luna Marques A, Mebus-Antunes NC, Neves-Martins TC, de Sá JM, Sanches K, Santana-Silva MC, Vasconcelos AA, da Silva Almeida M, de Amorim GC, Anobom CD, Da Poian AT, Gomes-Neto F, Pinheiro AS, Almeida FC. Insights into the specificity for the interaction of the promiscuous SARS-CoV-2 nucleocapsid protein N-terminal domain with deoxyribonucleic acids. Int J Biol Macromol 2022; 203:466-480. [PMID: 35077748 PMCID: PMC8783401 DOI: 10.1016/j.ijbiomac.2022.01.121] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/23/2022]
Abstract
The SARS-CoV-2 nucleocapsid protein (N) is a multifunctional promiscuous nucleic acid-binding protein, which plays a major role in nucleocapsid assembly and discontinuous RNA transcription, facilitating the template switch of transcriptional regulatory sequences (TRS). Here, we dissect the structural features of the N protein N-terminal domain (N-NTD) and N-NTD plus the SR-rich motif (N-NTD-SR) upon binding to single and double-stranded TRS DNA, as well as their activities for dsTRS melting and TRS-induced liquid-liquid phase separation (LLPS). Our study gives insights on the specificity for N-NTD(-SR) interaction with TRS. We observed an approximation of the triple-thymidine (TTT) motif of the TRS to β-sheet II, giving rise to an orientation difference of ~25° between dsTRS and non-specific sequence (dsNS). It led to a local unfavorable energetic contribution that might trigger the melting activity. The thermodynamic parameters of binding of ssTRSs and dsTRS suggested that the duplex dissociation of the dsTRS in the binding cleft is entropically favorable. We showed a preference for TRS in the formation of liquid condensates when compared to NS. Moreover, our results on DNA binding may serve as a starting point for the design of inhibitors, including aptamers, against N, a possible therapeutic target essential for the virus infectivity.
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Affiliation(s)
- Icaro Putinhon Caruso
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Multiuser Center for Biomolecular Innovation (CMIB), Department of Physics, São Paulo State University (UNESP), São José do Rio Preto, Brazil; Rio BioNMR Network, Rio de Janeiro, Brazil.
| | - Vitor dos Santos Almeida
- National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Mariana Juliani do Amaral
- Faculty of Pharmacy, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Protein Advanced Biochemistry (PAB), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Guilherme Caldas de Andrade
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Gabriela Rocha de Araújo
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Talita Stelling de Araújo
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Protein Advanced Biochemistry (PAB), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Jéssica Moreira de Azevedo
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Protein Advanced Biochemistry (PAB), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Glauce Moreno Barbosa
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Leonardo Bartkevihi
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Peter Reis Bezerra
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Katia Maria dos Santos Cabral
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Protein Advanced Biochemistry (PAB), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Isabella Otênio de Lourenço
- Multiuser Center for Biomolecular Innovation (CMIB), Department of Physics, São Paulo State University (UNESP), São José do Rio Preto, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Clara L.F. Malizia-Motta
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Aline de Luna Marques
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Multidisciplinary Center for Research in Biology (NUMPEX), Campus Duque de Caxias Federal University of Rio de Janeiro, Duque de Caxias, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Nathane Cunha Mebus-Antunes
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Thais Cristtina Neves-Martins
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Jéssica Maróstica de Sá
- Multiuser Center for Biomolecular Innovation (CMIB), Department of Physics, São Paulo State University (UNESP), São José do Rio Preto, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Karoline Sanches
- Multiuser Center for Biomolecular Innovation (CMIB), Department of Physics, São Paulo State University (UNESP), São José do Rio Preto, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Marcos Caique Santana-Silva
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Multidisciplinary Center for Research in Biology (NUMPEX), Campus Duque de Caxias Federal University of Rio de Janeiro, Duque de Caxias, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Ariana Azevedo Vasconcelos
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Marcius da Silva Almeida
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Protein Advanced Biochemistry (PAB), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Gisele Cardoso de Amorim
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Multidisciplinary Center for Research in Biology (NUMPEX), Campus Duque de Caxias Federal University of Rio de Janeiro, Duque de Caxias, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Cristiane Dinis Anobom
- National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Andrea T. Da Poian
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Francisco Gomes-Neto
- National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Laboratory of Toxinology, Oswaldo Cruz Foundation (FIOCRUZ), Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Anderson S. Pinheiro
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil
| | - Fabio C.L. Almeida
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil,Rio BioNMR Network, Rio de Janeiro, Brazil,Correspondence to: F.C.L. Almeida, National Center of Nuclear Magnetic Resonance (CNRMN), CENABIO, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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8
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Preparation of substrates for microarray protein chips with different ending functional groups. J Immunol Methods 2022; 502:113218. [PMID: 35026296 DOI: 10.1016/j.jim.2022.113218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 08/26/2021] [Accepted: 01/03/2022] [Indexed: 11/20/2022]
Abstract
Protein microarray chips are composed of three components, these are pre-treatment substrates, surface chemical modification, and immobilizing protein on substrate surfaces. In this study, self-assembly monolayers are used for surface chemical modification. Using this method, silanization on a glass and silicon chip is achieved, forming the terminal group substrates. Modification of the substrate surface to provide COOH and NH2 terminal functional groups provides a mechanism to proteins to immobilize on the substrate surface. To observe immobilized proteins on the substrate surface, they are first labeled with Cy5 fluorescent dye before analysis using a GenePix 4000B Microarray Scanner. The scanner induces fluorescence in the labelling dye and the resulting light is analyzed to provide information concerning both the quantity of immobilized protein, and the orientation of attachment. The antigen of the HSV-1 virus, a common human virus, was used in this study, performing an antigen-antibody analysis to determine the efficacy of the method under test for clinical diagnosis.
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9
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De Vos J, Pereira Aguilar P, Köppl C, Fischer A, Grünwald-Gruber C, Dürkop M, Klausberger M, Mairhofer J, Striedner G, Cserjan-Puschmann M, Jungbauer A, Lingg N. Production of full-length SARS-CoV-2 nucleocapsid protein from Escherichia coli optimized by native hydrophobic interaction chromatography hyphenated to multi-angle light scattering detection. Talanta 2021; 235:122691. [PMID: 34517577 PMCID: PMC8284068 DOI: 10.1016/j.talanta.2021.122691] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 11/22/2022]
Abstract
The nucleocapsid protein (NP) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for several steps of the viral life cycle, and is abundantly expressed during infection, making it an ideal diagnostic target protein. This protein has a strong tendency for dimerization and interaction with nucleic acids. For the first time, high titers of NP were expressed in E. coli with a CASPON tag, using a growth-decoupled protein expression system. Purification was accomplished by nuclease treatment of the cell homogenate and a sequence of downstream processing (DSP) steps. An analytical method consisting of native hydrophobic interaction chromatography hyphenated to multi-angle light scattering detection (HIC-MALS) was established for in-process control, in particular, to monitor product fragmentation and multimerization throughout the purification process. 730 mg purified NP per liter of fermentation could be produced by the optimized process, corresponding to a yield of 77% after cell lysis. The HIC-MALS method was used to demonstrate that the NP product can be produced with a purity of 95%. The molecular mass of the main NP fraction is consistent with dimerized protein as was verified by a complementary native size-exclusion separation (SEC)-MALS analysis. Peptide mapping mass spectrometry and host cell specific enzyme-linked immunosorbent assay confirmed the high product purity, and the presence of a minor endogenous chaperone explained the residual impurities. The optimized HIC-MALS method enables monitoring of the product purity, and simultaneously access its molecular mass, providing orthogonal information complementary to established SEC-MALS methods. Enhanced resolving power can be achieved over SEC, attributed to the extended variables to tune selectivity in HIC mode.
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Affiliation(s)
- Jelle De Vos
- Vrije Universiteit Brussel, Department of Chemical Engineering, 1050, Brussels, Belgium; Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria
| | - Patricia Pereira Aguilar
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria.
| | - Christoph Köppl
- acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria
| | - Andreas Fischer
- acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria
| | - Clemens Grünwald-Gruber
- BOKU Core Facility Mass Spectrometry, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190, Vienna, Austria
| | - Mark Dürkop
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; Novasign GmbH, 1190, Vienna, Austria
| | - Miriam Klausberger
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria
| | | | - Gerald Striedner
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria; enGenes Biotech GmbH, 1190, Vienna, Austria
| | - Monika Cserjan-Puschmann
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria
| | - Alois Jungbauer
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria
| | - Nico Lingg
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna (BOKU), 1190 Vienna, Austria; acib - Austrian Centre of Industrial Biotechnology, 1190, Vienna, Austria
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10
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Di D, Dileepan M, Ahmed S, Liang Y, Ly H. Recombinant SARS-CoV-2 Nucleocapsid Protein: Expression, Purification, and Its Biochemical Characterization and Utility in Serological Assay Development to Assess Immunological Responses to SARS-CoV-2 Infection. Pathogens 2021; 10:1039. [PMID: 34451501 PMCID: PMC8402198 DOI: 10.3390/pathogens10081039] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/08/2021] [Accepted: 08/14/2021] [Indexed: 12/23/2022] Open
Abstract
The SARS-CoV-2 nucleocapsid protein (N) binds a single-stranded viral RNA genome to form a helical ribonucleoprotein complex that is packaged into virion particles. N is relatively conserved among coronaviruses and consists of the N-terminal domain (NTD) and C-terminal domain (CTD), which are flanked by three disorganized regions. N is highly immunogenic and has been widely used to develop a serological assay as a diagnostic tool for COVID-19 infection, although there is a concern that the natural propensity of N to associate with RNA might compromise the assay's specificity. We expressed and purified from bacterial cells two recombinant forms of SARS-CoV-2 N, one from the soluble fraction of bacterial cell lysates that is strongly associated with bacterial RNAs and the other that is completely devoid of RNAs. We showed that both forms of N can be used to develop enzyme-linked immunosorbent assays (ELISAs) for the specific detection of human and mouse anti-N monoclonal antibodies (mAb) as well as feline SARS-CoV-2 seropositive serum samples, but that the RNA-free form of N exhibits a slightly higher level of sensitivity than the RNA-bound form to react to anti-N mouse mAb. Using the electrophoretic mobility shift assay (EMSA), we also showed that N preferentially binds ssRNA in a sequence-independent manner and that both NTD and CTD of N contribute to RNA-binding activity. Collectively, our study describes methods to express, purify, and biochemically characterize the SARS-CoV-2 N protein and to use it for the development of serological assays to detect SARS-CoV-2 infection.
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Affiliation(s)
| | | | | | - Yuying Liang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN 55108, USA; (D.D.); (M.D.); (S.A.)
| | - Hinh Ly
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St Paul, MN 55108, USA; (D.D.); (M.D.); (S.A.)
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11
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Zhao H, Wu D, Nguyen A, Li Y, Adão RC, Valkov E, Patterson GH, Piszczek G, Schuck P. Energetic and structural features of SARS-CoV-2 N-protein co-assemblies with nucleic acids. iScience 2021; 24:102523. [PMID: 33997662 PMCID: PMC8103780 DOI: 10.1016/j.isci.2021.102523] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/26/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023] Open
Abstract
Nucleocapsid (N) protein of the SARS-CoV-2 virus packages the viral genome into well-defined ribonucleoprotein particles, but the molecular pathway is still unclear. N-protein is dimeric and consists of two folded domains with nucleic acid (NA) binding sites, surrounded by intrinsically disordered regions that promote liquid-liquid phase separation. Here, we use biophysical tools to study N-protein interactions with oligonucleotides of different lengths, examining the size, composition, secondary structure, and energetics of the resulting states. We observe the formation of supramolecular clusters or nuclei preceding growth into phase-separated droplets. Short hexanucleotide NA forms compact 2:2 N-protein/NA complexes with reduced disorder. Longer oligonucleotides expose additional N-protein interactions and multi-valent protein-NA interactions, which generate higher-order mixed oligomers and simultaneously promote growth of droplets. Phase separation is accompanied by a significant change in protein secondary structure, different from that caused by initial NA binding, which may contribute to the assembly of ribonucleoprotein particles within macromolecular condensates.
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Affiliation(s)
- Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Di Wu
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD 20892, USA
| | - Ai Nguyen
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Yan Li
- Protein/Peptide Sequencing Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Regina C. Adão
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Eugene Valkov
- Messenger RNA Regulation and Decay Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Building 560, Room 21-105A, Frederick, MD 21702, USA
| | - George H. Patterson
- Section on Biophotonics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA
| | - Grzegorz Piszczek
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD 20892, USA
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
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12
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Gorkhali R, Koirala P, Rijal S, Mainali A, Baral A, Bhattarai HK. Structure and Function of Major SARS-CoV-2 and SARS-CoV Proteins. Bioinform Biol Insights 2021; 15:11779322211025876. [PMID: 34220199 PMCID: PMC8221690 DOI: 10.1177/11779322211025876] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/25/2021] [Indexed: 01/20/2023] Open
Abstract
SARS-CoV-2 virus, the causative agent of COVID-19 pandemic, has a genomic organization consisting of 16 nonstructural proteins (nsps), 4 structural proteins, and 9 accessory proteins. Relative of SARS-CoV-2, SARS-CoV, has genomic organization, which is very similar. In this article, the function and structure of the proteins of SARS-CoV-2 and SARS-CoV are described in great detail. The nsps are expressed as a single or two polyproteins, which are then cleaved into individual proteins using two proteases of the virus, a chymotrypsin-like protease and a papain-like protease. The released proteins serve as centers of virus replication and transcription. Some of these nsps modulate the host’s translation and immune systems, while others help the virus evade the host immune system. Some of the nsps help form replication-transcription complex at double-membrane vesicles. Others, including one RNA-dependent RNA polymerase and one exonuclease, help in the polymerization of newly synthesized RNA of the virus and help minimize the mutation rate by proofreading. After synthesis of the viral RNA, it gets capped. The capping consists of adding GMP and a methylation mark, called cap 0 and additionally adding a methyl group to the terminal ribose called cap1. Capping is accomplished with the help of a helicase, which also helps remove a phosphate, two methyltransferases, and a scaffolding factor. Among the structural proteins, S protein forms the receptor of the virus, which latches on the angiotensin-converting enzyme 2 receptor of the host and N protein binds and protects the genomic RNA of the virus. The accessory proteins found in these viruses are small proteins with immune modulatory roles. Besides functions of these proteins, solved X-ray and cryogenic electron microscopy structures related to the function of the proteins along with comparisons to other coronavirus homologs have been described in the article. Finally, the rate of mutation of SARS-CoV-2 residues of the proteome during the 2020 pandemic has been described. Some proteins are mutated more often than other proteins, but the significance of these mutation rates is not fully understood.
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Affiliation(s)
- Ritesh Gorkhali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | | | - Sadikshya Rijal
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Ashmita Mainali
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
| | - Adesh Baral
- Department of Biotechnology, Kathmandu University, Dhulikhel, Nepal
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13
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Kaur M, Sharma A, Kumar S, Singh G, Barnwal RP. SARS-CoV-2: Insights into its structural intricacies and functional aspects for drug and vaccine development. Int J Biol Macromol 2021; 179:45-60. [PMID: 33662418 PMCID: PMC7919520 DOI: 10.1016/j.ijbiomac.2021.02.212] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/04/2021] [Accepted: 02/27/2021] [Indexed: 12/11/2022]
Abstract
Globally, SARS-CoV-2 has emerged as threat to life and economy. Researchers are trying to find a cure against this pathogen but without much success. Several attempts have been made to understand the atomic level details of SARS-CoV-2 in the past few months. However, one review with all structural details for drug and vaccine development has been missing. Hence, this review aims to summarize key functional roles played by various domains of SARS-CoV-2 genome during its entry into the host, replication, repression of host immune response and overall viral life cycle. Additionally, various proteins of SARS-CoV-2 for finding a potent inhibitor have also been highlighted. To mitigate this deadly virus, an understanding of atomic level information, pathogenicity mechanisms and functions of different proteins in causing the infection is imperative. Thus, these structural details would finally pave the way for development of a potential drug/vaccine against the disease caused by SARS-CoV-2.
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Affiliation(s)
- Mandeep Kaur
- Department of Biophysics, Panjab University, Chandigarh 160014, India
| | - Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh 160014, India; UIPS, Panjab University, Chandigarh 160014, India
| | - Santosh Kumar
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Gurpal Singh
- UIPS, Panjab University, Chandigarh 160014, India
| | - Ravi P Barnwal
- Department of Biophysics, Panjab University, Chandigarh 160014, India.
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14
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Zhao H, Wu D, Nguyen A, Li Y, Adão RC, Valkov E, Patterson GH, Piszczek G, Schuck P. Energetic and structural features of SARS-CoV-2 N-protein co-assemblies with nucleic acids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.02.08.430344. [PMID: 33594360 PMCID: PMC7885910 DOI: 10.1101/2021.02.08.430344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Nucleocapsid (N) protein of the SARS-CoV-2 virus packages the viral genome into well-defined ribonucleoprotein particles, but the molecular pathway is still unclear. N-protein is dimeric and consists of two folded domains with nucleic acid (NA) binding sites, surrounded by intrinsically disordered regions that promote liquid-liquid phase separation. Here we use biophysical tools to study N-protein interactions with oligonucleotides of different length, examining the size, composition, secondary structure, and energetics of the resulting states. We observe formation of supramolecular clusters or nuclei preceding growth into phase-separated droplets. Short hexanucleotide NA forms compact 2:2 N-protein/NA complexes with reduced disorder. Longer oligonucleotides expose additional N-protein interactions and multi-valent protein-NA interactions, which generate higher-order mixed oligomers and simultaneously promote growth of droplets. Phase separation is accompanied by a significant increase in protein secondary structure, different from that caused by initial NA binding, which may contribute to the assembly of ribonucleoprotein particles within molecular condensates.
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Affiliation(s)
- Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Di Wu
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD 20892, USA
| | - Ai Nguyen
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Yan Li
- Protein/Peptide Sequencing Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Regina C. Adão
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
| | - Eugene Valkov
- Messenger RNA Regulation and Decay Section, RNA Biology Laboratory, Center for Cancer Research, National Cancer Institute, Building 560, Room 21–105A, Frederick, MD 21702
| | - George H. Patterson
- Section on Biophotonics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Grzegorz Piszczek
- Biophysics Core Facility, National Heart, Lung, and Blood Institute, 50 South Drive, Bethesda, MD 20892, USA
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, 13 South Drive, Bethesda, MD 20892, USA
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15
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Khan MT, Irfan M, Ahsan H, Ahmed A, Kaushik AC, Khan AS, Chinnasamy S, Ali A, Wei DQ. Structures of SARS-CoV-2 RNA-Binding Proteins and Therapeutic Targets. Intervirology 2021; 64:55-68. [PMID: 33454715 PMCID: PMC7900486 DOI: 10.1159/000513686] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/10/2020] [Indexed: 11/19/2022] Open
Abstract
Background The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemic has resulted in thousands of infections and deaths worldwide. Several therapies are currently undergoing clinical trials for the treatment of SARS-CoV-2 infection. However, the development of new drugs and the repositioning of existing drugs can only be achieved after the identification of potential therapeutic targets within structures, as this strategy provides the most precise solution for developing treatments for sudden epidemic infectious diseases. Summary In the current investigation, crystal and cryo-electron microscopy structures encoded by the SARS-CoV-2 genome were systematically examined for the identification of potential drug targets. These structures include nonstructural proteins (Nsp-9; Nsp-12; and Nsp-15), nucleocapsid (N) proteins, and the main protease (Mpro). Key Message The structural information reveals the presence of many potential alternative therapeutic targets, primarily involved in interaction between N protein and Nsp3, forming replication-transcription complexes (RTCs) which might be a potential drug target for effective control of current SARS-CoV-2 pandemic. RTCs consist of 16 nonstructural proteins (Nsp1-16) that play the most essential role in the synthesis of viral RNA. Targeting the physical linkage between the envelope and single-stranded positive RNA, a process facilitated by matrix proteins may provide a good alternative strategy. Our current study provides useful information for the development of new lead compounds against SARS-CoV-2 infections.
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Affiliation(s)
- Muhammad Tahir Khan
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan.,School of Life Sciences and Biotechnology, and Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Muhammad Irfan
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Hina Ahsan
- Riphah Institute of Pharmaceutical Sciences, Riphah International University, Islamabad, Pakistan
| | - Abrar Ahmed
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | | | - Anwar Sheed Khan
- Department of Microbiology, University of Science and Technology, Kohat, Pakistan
| | - Sathishkumar Chinnasamy
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, and Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Arif Ali
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, and Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, and Joint Laboratory of International Cooperation in Metabolic and Developmental Sciences, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China, .,Peng Cheng Laboratory, Shenzhen, China,
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16
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Balmeh N, Mahmoudi S, Fard NA. Manipulated bio antimicrobial peptides from probiotic bacteria as proposed drugs for COVID-19 disease. INFORMATICS IN MEDICINE UNLOCKED 2021; 23:100515. [PMID: 33521241 PMCID: PMC7832255 DOI: 10.1016/j.imu.2021.100515] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 02/07/2023] Open
Abstract
Coronavirus disease 19 (COVID-19) is the latest pandemic resulted from the coronavirus family. Due to the high prevalence of this disease, its high mortality rate, and the lack of effective treatment, the need for affordable and accessible drugs is one of the main challenges in this regard. It has been proved that RdRp, 3CL, Spike, and Nucleocapsid are the most important viral proteins playing vital roles in the processes of proliferation and infection. Therefore, we started studying a wide range of bio-peptides and then conducted molecular docking analyses to investigate their binding affinity for the inhibition of these proteins. After obtaining the best bio-peptides with the highest affinity scores, they were examined for further study and then manipulated to eliminate their side effects. Additionally, the molecular dynamic simulation was performed to validate the structure and interaction stability. The results of this study reveal that glycocin F from Lactococcus lactis and lactococcine G from Lactobacillus plantarum had the high affinities to bind to the viral proteins, and the manipulation of their sequence also led to the side effects' elimination. In addition, in some cases, their affinities to attach the SARS-CoV-2 proteins have increased. It seems that these two drugs which were discovered and designed, are optimal for treating the COVID-19 infection. However, experimental and pre-clinical studies are necessary to assay their therapeutic effects.
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Affiliation(s)
- Negar Balmeh
- Department of Cell and Molecular Biology, School of Biology, Nour Danesh Institution of Higher Education, Meymeh, Iran
| | - Samira Mahmoudi
- Department of Microbial Biotechnology, School of Biological Sciences, Islamic Azad University Tehran North Branch, Tehran, Iran
| | - Najaf Allahyari Fard
- Department of Systems Biotechnology, National Institute of Genetic Engineering & Biotechnology (NIGEB), Tehran, Iran
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17
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Abstract
Many research teams all over the world focus their research on the SARS-CoV-2, the new coronavirus that causes the so-called COVID-19 disease. Most of the studies identify the main protease or 3C-like protease (Mpro/3CLpro) as a valid target for large-spectrum inhibitors. Also, the interaction of the human receptor angiotensin-converting enzyme 2 (ACE2) with the viral surface glycoprotein (S) is studied in depth. Structural studies tried to identify the residues responsible for enhancement/weaken virus-ACE2 interactions or the cross-reactivity of the neutralizing antibodies. Although the understanding of the immune system and the hyper-inflammatory process in COVID-19 are crucial for managing the immediate and the long-term consequences of the disease, not many X-ray/NMR/cryo-EM crystals are available. In addition to 3CLpro, the crystal structures of other nonstructural proteins offer valuable information for elucidating some aspects of the SARS-CoV-2 infection. Thus, the structural analysis of the SARS-CoV-2 is currently mainly focused on three directions-finding Mpro/3CLpro inhibitors, the virus-host cell invasion, and the virus-neutralizing antibody interaction.
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Affiliation(s)
- Mihaela Ileana Ionescu
- Department of Microbiology, Iuliu Hațieganu University of Medicine and Pharmacy, 6 Louis Pasteur, 400349, Cluj-Napoca, Romania.
- Department of Microbiology, County Emergency Clinical Hospital, 400006, Cluj-Napoca, Romania.
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18
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Khodadadi E, Maroufi P, Khodadadi E, Esposito I, Ganbarov K, Espsoito S, Yousefi M, Zeinalzadeh E, Kafil HS. Study of combining virtual screening and antiviral treatments of the Sars-CoV-2 (Covid-19). Microb Pathog 2020; 146:104241. [PMID: 32387389 PMCID: PMC7199731 DOI: 10.1016/j.micpath.2020.104241] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 02/07/2023]
Abstract
The recent epidemic outbreak of a novel human coronavirus called SARS-CoV-2 and causing the respiratory tract disease COVID-19 has reached worldwide resonance and a global effort is being undertaken to characterize the molecular features and evolutionary origins of this virus. Therefore, rapid and accurate identification of pathogenic viruses plays a vital role in selecting appropriate treatments, saving people's lives and preventing epidemics. Additionally, general treatments, coronavirus-specific treatments, and antiviral treatments useful in fighting COVID-19 are addressed. This review sets out to shed light on the SARS-CoV-2 and host receptor recognition, a crucial factor for successful virus infection and taking immune-informatics approaches to identify B- and T-cell epitopes for surface glycoprotein of SARS-CoV-2. A variety of improved or new approaches also have been developed. It is anticipated that this will assist researchers and clinicians in developing better techniques for timely and effective detection of coronavirus infection. Moreover, the genomic sequence of the virus responsible for COVID-19, as well as the experimentally determined three-dimensional structure of the Main protease (Mpro) is available. The reported structure of the target Mpro was described in this review to identify potential drugs for COVID-19 using virtual high throughput screening.
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Affiliation(s)
- Ehsaneh Khodadadi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Parham Maroufi
- Department of Orthopedy, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Ehsan Khodadadi
- Department of Biology, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
| | | | | | | | - Mehdi Yousefi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Elham Zeinalzadeh
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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Nikolakaki E, Giannakouros T. SR/RS Motifs as Critical Determinants of Coronavirus Life Cycle. Front Mol Biosci 2020; 7:219. [PMID: 32974389 PMCID: PMC7471607 DOI: 10.3389/fmolb.2020.00219] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/04/2020] [Indexed: 01/24/2023] Open
Abstract
SR/RS domains are found in almost all eukaryotic genomes from C. elegans to human. These domains are thought to mediate interactions between proteins but also between proteins and RNA in complex networks associated with mRNA splicing, chromatin structure, transcription, cell cycle and cell structure. A precise and tight regulation of their function is achieved through phosphorylation of a number of serine residues within the SR/RS motifs by the Serine-Arginine protein kinases (SRPKs) that lead to delicate structural alterations. Given that coronavirus N proteins also contain SR/RS domains, we formulate the hypothesis that the viruses exploit the properties of these motifs to promote unpacking of viral RNA and virion assembly.
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Affiliation(s)
- Eleni Nikolakaki
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University, Thessaloniki, Greece
| | - Thomas Giannakouros
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University, Thessaloniki, Greece
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Abstract
Severe acute respiratory syndrome virus 2 (SARS-CoV-2) belongs to the single-stranded positive-sense RNA family. The virus contains a large genome that encodes four structural proteins, small envelope (E), matrix (M), nucleocapsid phosphoprotein (N), spike (S), and 16 nonstructural proteins (nsp1-16) that together, ensure replication of the virus in the host cell. Among these proteins, the interactions of N and Nsp3 are essential that links the viral genome for processing. The N proteins reside at CoV RNA synthesis sites known as the replication-transcription complexes (RTCs). The N-terminal of N has RNA-binding domain (N-NTD), capturing the RNA genome while the C-terminal domain (N-CTD) anchors the viral Nsp3, a component of RTCs. Although the structural information has been recently released, the residues involved in contacts between N-CTD with Nsp3 are still unknown. To find the residues involved in interactions between two proteins, three-dimensional structures of both proteins were retrieved and docked using HADDOCK. Residues at N-CTD were detected in interaction with L499, R500, K501, V502, P503, T504, D505, N506, Y507, I508, T509, K529, K530K532, S533 of Nsp3 and N-NTD to synthesize SARS-CoV-2 RNA. The interaction between Nsp3 and CTD of N protein may be a potential drug target. The current study provides information for better understanding the interaction between N protein and Nsp3 that could be a possible target for future inhibitors.
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21
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SARS-CoV-2 nucleocapsid and Nsp3 binding: an in silico study. Arch Microbiol 2020; 203:59-66. [PMID: 32749662 PMCID: PMC7401470 DOI: 10.1007/s00203-020-01998-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/16/2020] [Accepted: 07/23/2020] [Indexed: 12/18/2022]
Abstract
Severe acute respiratory syndrome virus 2 (SARS-CoV-2) belongs to the single-stranded positive-sense RNA family. The virus contains a large genome that encodes four structural proteins, small envelope (E), matrix (M), nucleocapsid phosphoprotein (N), spike (S), and 16 nonstructural proteins (nsp1-16) that together, ensure replication of the virus in the host cell. Among these proteins, the interactions of N and Nsp3 are essential that links the viral genome for processing. The N proteins reside at CoV RNA synthesis sites known as the replication-transcription complexes (RTCs). The N-terminal of N has RNA-binding domain (N-NTD), capturing the RNA genome while the C-terminal domain (N-CTD) anchors the viral Nsp3, a component of RTCs. Although the structural information has been recently released, the residues involved in contacts between N-CTD with Nsp3 are still unknown. To find the residues involved in interactions between two proteins, three-dimensional structures of both proteins were retrieved and docked using HADDOCK. Residues at N-CTD were detected in interaction with L499, R500, K501, V502, P503, T504, D505, N506, Y507, I508, T509, K529, K530K532, S533 of Nsp3 and N-NTD to synthesize SARS-CoV-2 RNA. The interaction between Nsp3 and CTD of N protein may be a potential drug target. The current study provides information for better understanding the interaction between N protein and Nsp3 that could be a possible target for future inhibitors.
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22
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Amin M, Abbas G. Docking study of chloroquine and hydroxychloroquine interaction with RNA binding domain of nucleocapsid phospho-protein - an in silico insight into the comparative efficacy of repurposing antiviral drugs. J Biomol Struct Dyn 2020; 39:4243-4255. [PMID: 32469265 DOI: 10.1080/07391102.2020.1775703] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Recent outbreak of novel Coronavirus disease () pandemic around the world is associated with severe acute respiratory syndrome. The death toll associated with the pandemic is increasing day by day. SARS-CoV-2 is an enveloped virus and its N terminal domain (NTD) of Nucleocapsid protein (N protein) binds to the viral (+) sense RNA and results in virus ribonucleoprotien complex, essential for the virus replication. The N protein is composed of a serine-rich linker region sandwiched between NTD and C terminal (CTD). These terminals play a role in viral entry and its processing post entry. The NTD of SARS-CoV-2 N protein forms orthorhombic crystals and binds to the viral genome. Therefore, there is always a quest to target RNA binding domain of nucleocapsid phosphoprotein (NTD-N-protein which in turn may help in controlling diseases caused by SARS-CoV-2 in humans. The role of Chloroquine and Hydroxychloroquine as potential treatments for is still under debate globally because of some side effects associated with it. This study involves the In silico interactions of Chloroquine and Hydroxychloroquine with the NTD-N-protein of SARS-CoV-2. With the help of various computational methods, we have explored the potential role of both of these antiviral drugs for the treatment of patients by comparing the efficacy of both of the drugs to bind to NTD-N-protein. In our research Hydroxychloroquine exhibited potential inhibitory effects of NTD-N-protein with binding energy -7.28 kcal/mol than Chloroquine (-6.30 kcal/mol) at SARS-CoV-2 receptor recognition of susceptible cells. The outcomes of this research strongly appeal for in vivo trials of Hydroxychloroquine for the patients infected with . Furthermore, the recommended doses of Hydroxychloroquine may reduce the chances of catching to the healthcare workers and staff who are in contact with or delivering direct care to coronavirus patients as long as they have not been diagnosed with . We further hypothesize that the comparative NTD-N-protein -drug docking interactions may help to understand the comparative efficacy of other candidate repurposing drugs until discovery of a proper vaccine.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Muhammad Amin
- Department of Chemistry, University of Sargodha, Sargodha, Pakistan
| | - Ghazanfar Abbas
- Department of Chemistry, University of Sargodha, Sargodha, Pakistan
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23
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Kang S, Yang M, Hong Z, Zhang L, Huang Z, Chen X, He S, Zhou Z, Zhou Z, Chen Q, Yan Y, Zhang C, Shan H, Chen S. Crystal structure of SARS-CoV-2 nucleocapsid protein RNA binding domain reveals potential unique drug targeting sites. Acta Pharm Sin B 2020; 10:1228-1238. [PMID: 32363136 PMCID: PMC7194921 DOI: 10.1016/j.apsb.2020.04.009] [Citation(s) in RCA: 446] [Impact Index Per Article: 111.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/19/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
The outbreak of coronavirus disease (COVID-19) caused by SARS-CoV-2 virus continually lead to worldwide human infections and deaths. Currently, there is no specific viral protein-targeted therapeutics. Viral nucleocapsid protein is a potential antiviral drug target, serving multiple critical functions during the viral life cycle. However, the structural information of SARS-CoV-2 nucleocapsid protein remains unclear. Herein, we have determined the 2.7 Å crystal structure of the N-terminal RNA binding domain of SARS-CoV-2 nucleocapsid protein. Although the overall structure is similar as other reported coronavirus nucleocapsid protein N-terminal domain, the surface electrostatic potential characteristics between them are distinct. Further comparison with mild virus type HCoV-OC43 equivalent domain demonstrates a unique potential RNA binding pocket alongside the β-sheet core. Complemented by in vitro binding studies, our data provide several atomic resolution features of SARS-CoV-2 nucleocapsid protein N-terminal domain, guiding the design of novel antiviral agents specific targeting to SARS-CoV-2.
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Affiliation(s)
- Sisi Kang
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Mei Yang
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Zhongsi Hong
- Department of Infectious Diseases, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Liping Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Institution of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Zhaoxia Huang
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Xiaoxue Chen
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Suhua He
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Ziliang Zhou
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Zhechong Zhou
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Qiuyue Chen
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Yan Yan
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
| | - Changsheng Zhang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Institution of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Hong Shan
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Department of Interventional Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Corresponding authors. Tel: +86 13612221254 (Shoudeng Chen), +86 18207306672 (Hong Shan).
| | - Shoudeng Chen
- Molecular Imaging Center, Guangdong Provincial Key Laboratory of Biomedical Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Guangdong Provincial Engineering Research Center of Molecular Imaging, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Department of Experimental Medicine, the Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China
- Corresponding authors. Tel: +86 13612221254 (Shoudeng Chen), +86 18207306672 (Hong Shan).
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24
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Deejai N, Roshorm YM, Kubera A. Antiviral Compounds Against Nucleocapsid Protein of Porcine Epidemic Diarrhea Virus. Anim Biotechnol 2016; 28:120-130. [PMID: 27791596 DOI: 10.1080/10495398.2016.1232268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Porcine epidemic diarrhea (PED) is a severe diarrhea disease in swine that is caused by porcine epidemic diarrhea virus (PEDV). Nucleocapsid (N) protein is the RNA-binding protein of PEDV, which plays an important role for virus life cycle. The aim of this research was to screen and characterize the compounds that could inhibit the activity of PEDV N protein. The gene encoding PEDV N protein obtained from PEDV Thai isolate was cloned and expressed in E. coli. Its amino acid sequence was employed to generate the three dimensional structure by homology modeling. There were 1,286 compounds of FDA-approved drug database that could virtually bind to the RNA-binding region of N protein. Three compounds, trichlormethiazide, D-(+) biotin, and glutathione successfully bound to the N protein, in vitro, with the IC50 at 8.754 mg/mL, 0.925 mg/mL, and 2.722 mg/mL. Antiviral activity in PEDV-infected Vero cells demonstrated that the effective concentration of trichlormethiazide, D-(+) biotin, and glutathione in inhibiting PEDV replication were 0.094, 0.094 and 1.5 mg/mL. This study demonstrated a strategy applied for discovery of antiviral agents capable of inhibiting PEDV N protein and PEDV replication. The compounds identified here exhibited a potential use as therapeutic agents for controlling PEDV infection.
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Affiliation(s)
- Nipaporn Deejai
- a Department of Genetics, Faculty of Science , Kasetsart University , Bangkok , Thailand
| | - Yaowaluck Maprang Roshorm
- b Division of Biotechnology, School of Bioresources and Technology , King Mongkut's University Thonburi , Bangkok , Thailand
| | - Anchanee Kubera
- a Department of Genetics, Faculty of Science , Kasetsart University , Bangkok , Thailand.,c Centre for Advanced Studies in Tropical Natural Resources , Kasetsart University , Bangkok , Thailand
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Recent insights into the development of therapeutics against coronavirus diseases by targeting N protein. Drug Discov Today 2015; 21:562-72. [PMID: 26691874 PMCID: PMC7108309 DOI: 10.1016/j.drudis.2015.11.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/11/2015] [Accepted: 11/30/2015] [Indexed: 12/18/2022]
Abstract
Coronavirus nucleocapsid proteins are appealing drug targets against coronavirus-induced diseases. A variety of compounds targeting the coronavirus nucleocapsid protein have been developed. Many of these compounds show potential antiviral activity.
The advent of severe acute respiratory syndrome (SARS) in the 21st century and the recent outbreak of Middle-East respiratory syndrome (MERS) highlight the importance of coronaviruses (CoVs) as human pathogens, emphasizing the need for development of novel antiviral strategies to combat acute respiratory infections caused by CoVs. Recent studies suggest that nucleocapsid (N) proteins from coronaviruses and other viruses can be useful antiviral drug targets against viral infections. This review aims to provide readers with a concise survey of the structural features of coronavirus N proteins and how these features provide insights into structure-based development of therapeutics against coronaviruses. We will also present our latest results on MERS-CoV N protein and its potential as an antiviral drug target.
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26
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The Nucleocapsid Protein of Coronaviruses Acts as a Viral Suppressor of RNA Silencing in Mammalian Cells. J Virol 2015; 89:9029-43. [PMID: 26085159 DOI: 10.1128/jvi.01331-15] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
RNA interference (RNAi) is a process of eukaryotic posttranscriptional gene silencing that functions in antiviral immunity in plants, nematodes, and insects. However, recent studies provided strong supports that RNAi also plays a role in antiviral mechanism in mammalian cells. To combat RNAi-mediated antiviral responses, many viruses encode viral suppressors of RNA silencing (VSR) to facilitate their replication. VSRs have been widely studied for plant and insect viruses, but only a few have been defined for mammalian viruses currently. We identified a novel VSR from coronaviruses, a group of medically important mammalian viruses including Severe acute respiratory syndrome coronavirus (SARS-CoV), and showed that the nucleocapsid protein (N protein) of coronaviruses suppresses RNAi triggered by either short hairpin RNAs or small interfering RNAs in mammalian cells. Mouse hepatitis virus (MHV) is closely related to SARS-CoV in the family Coronaviridae and was used as a coronavirus replication model. The replication of MHV increased when the N proteins were expressed in trans, while knockdown of Dicer1 or Ago2 transcripts facilitated the MHV replication in mammalian cells. These results support the hypothesis that RNAi is a part of the antiviral immunity responses in mammalian cells. IMPORTANCE RNAi has been well known to play important antiviral roles from plants to invertebrates. However, recent studies provided strong supports that RNAi is also involved in antiviral response in mammalian cells. An important indication for RNAi-mediated antiviral activity in mammals is the fact that a number of mammalian viruses encode potent suppressors of RNA silencing. Our results demonstrate that coronavirus N protein could function as a VSR through its double-stranded RNA binding activity. Mutational analysis of N protein allowed us to find out the critical residues for the VSR activity. Using the MHV-A59 as the coronavirus replication model, we showed that ectopic expression of SARS-CoV N protein could promote MHV replication in RNAi-active cells but not in RNAi-depleted cells. These results indicate that coronaviruses encode a VSR that functions in the replication cycle and provide further evidence to support that RNAi-mediated antiviral response exists in mammalian cells.
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Zuwała K, Golda A, Kabala W, Burmistrz M, Zdzalik M, Nowak P, Kedracka-Krok S, Zarebski M, Dobrucki J, Florek D, Zeglen S, Wojarski J, Potempa J, Dubin G, Pyrc K. The nucleocapsid protein of human coronavirus NL63. PLoS One 2015; 10:e0117833. [PMID: 25700263 PMCID: PMC4336326 DOI: 10.1371/journal.pone.0117833] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 01/02/2015] [Indexed: 12/19/2022] Open
Abstract
Human coronavirus (HCoV) NL63 was first described in 2004 and is associated with respiratory tract disease of varying severity. At the genetic and structural level, HCoV-NL63 is similar to other members of the Coronavirinae subfamily, especially human coronavirus 229E (HCoV-229E). Detailed analysis, however, reveals several unique features of the pathogen. The coronaviral nucleocapsid protein is abundantly present in infected cells. It is a multi-domain, multi-functional protein important for viral replication and a number of cellular processes. The aim of the present study was to characterize the HCoV-NL63 nucleocapsid protein. Biochemical analyses revealed that the protein shares characteristics with homologous proteins encoded in other coronaviral genomes, with the N-terminal domain responsible for nucleic acid binding and the C-terminal domain involved in protein oligomerization. Surprisingly, analysis of the subcellular localization of the N protein of HCoV-NL63 revealed that, differently than homologous proteins from other coronaviral species except for SARS-CoV, it is not present in the nucleus of infected or transfected cells. Furthermore, no significant alteration in cell cycle progression in cells expressing the protein was observed. This is in stark contrast with results obtained for other coronaviruses, except for the SARS-CoV.
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Affiliation(s)
- Kaja Zuwała
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Anna Golda
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Wojciech Kabala
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Michał Burmistrz
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Michal Zdzalik
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Paulina Nowak
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Sylwia Kedracka-Krok
- Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Mirosław Zarebski
- Division of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jerzy Dobrucki
- Division of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Dominik Florek
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Sławomir Zeglen
- Department of Cardiac Surgery and Transplantology, Silesian Center for Heart Diseases, Szpitalna 2, 41–800, Zabrze, Poland
| | - Jacek Wojarski
- Department of Cardiac Surgery and Transplantology, Silesian Center for Heart Diseases, Szpitalna 2, 41–800, Zabrze, Poland
| | - Jan Potempa
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- Oral Health and Systemic Disease Research Group, School of Dentistry, University of Louisville, Louisville, KY, United States of America
| | - Grzegorz Dubin
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
| | - Krzysztof Pyrc
- Microbiology Department, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7, 30–387, Krakow, Poland
- * E-mail:
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Lin SY, Liu CL, Chang YM, Zhao J, Perlman S, Hou MH. Structural basis for the identification of the N-terminal domain of coronavirus nucleocapsid protein as an antiviral target. J Med Chem 2014; 57:2247-57. [PMID: 24564608 PMCID: PMC3983370 DOI: 10.1021/jm500089r] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Coronaviruses
(CoVs) cause numerous diseases, including Middle
East respiratory syndrome and severe acute respiratory syndrome, generating
significant health-related and economic consequences. CoVs encode
the nucleocapsid (N) protein, a major structural protein that plays
multiple roles in the virus replication cycle and forms a ribonucleoprotein
complex with the viral RNA through the N protein’s N-terminal
domain (N-NTD). Using human CoV-OC43 (HCoV-OC43) as a model for CoV,
we present the 3D structure of HCoV-OC43 N-NTD complexed with ribonucleoside
5′-monophosphates to identify a distinct ribonucleotide-binding
pocket. By targeting this pocket, we identified and developed a new
coronavirus N protein inhibitor, N-(6-oxo-5,6-dihydrophenanthridin-2-yl)(N,N-dimethylamino)acetamide hydrochloride
(PJ34), using virtual screening; this inhibitor reduced the N protein’s
RNA-binding affinity and hindered viral replication. We also determined
the crystal structure of the N-NTD–PJ34 complex. On the basis
of these findings, we propose guidelines for developing new N protein-based
antiviral agents that target CoVs.
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Affiliation(s)
- Shing-Yen Lin
- College of Life Science, ‡Institute of Genomics and Bioinformatics, and §Agriculture Biotechnology Center, National Chung Hsing University , Taichung 40254, Taiwan
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Zinzula L, Tramontano E. Strategies of highly pathogenic RNA viruses to block dsRNA detection by RIG-I-like receptors: hide, mask, hit. Antiviral Res 2013; 100:615-35. [PMID: 24129118 PMCID: PMC7113674 DOI: 10.1016/j.antiviral.2013.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/24/2013] [Accepted: 10/04/2013] [Indexed: 12/24/2022]
Abstract
dsRNA species are byproducts of RNA virus replication and/or transcription. Prompt detection of dsRNA by RIG-I like receptors (RLRs) is a hallmark of the innate immune response. RLRs activation triggers production of the type I interferon (IFN)-based antiviral response. Highly pathogenic RNA viruses encode proteins that block the RLRs pathway. Hide, mask and hit are 3 strategies of RNA viruses to avoid immune system activation.
Double-stranded RNA (dsRNA) is synthesized during the course of infection by RNA viruses as a byproduct of replication and transcription and acts as a potent trigger of the host innate antiviral response. In the cytoplasm of the infected cell, recognition of the presence of viral dsRNA as a signature of “non-self” nucleic acid is carried out by RIG-I-like receptors (RLRs), a set of dedicated helicases whose activation leads to the production of type I interferon α/β (IFN-α/β). To overcome the innate antiviral response, RNA viruses encode suppressors of IFN-α/β induction, which block RLRs recognition of dsRNA by means of different mechanisms that can be categorized into: (i) dsRNA binding and/or shielding (“hide”), (ii) dsRNA termini processing (“mask”) and (iii) direct interaction with components of the RLRs pathway (“hit”). In light of recent functional, biochemical and structural findings, we review the inhibition mechanisms of RLRs recognition of dsRNA displayed by a number of highly pathogenic RNA viruses with different disease phenotypes such as haemorrhagic fever (Ebola, Marburg, Lassa fever, Lujo, Machupo, Junin, Guanarito, Crimean-Congo, Rift Valley fever, dengue), severe respiratory disease (influenza, SARS, Hendra, Hantaan, Sin Nombre, Andes) and encephalitis (Nipah, West Nile).
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Affiliation(s)
- Luca Zinzula
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella di Monserrato, SS554, 09042 Monserrato (Cagliari), Italy.
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30
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Chen IJ, Yuann JMP, Chang YM, Lin SY, Zhao J, Perlman S, Shen YY, Huang TH, Hou MH. Crystal structure-based exploration of the important role of Arg106 in the RNA-binding domain of human coronavirus OC43 nucleocapsid protein. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1054-62. [PMID: 23501675 PMCID: PMC3774783 DOI: 10.1016/j.bbapap.2013.03.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 02/06/2013] [Accepted: 03/05/2013] [Indexed: 02/04/2023]
Abstract
Human coronavirus OC43 (HCoV-OC43) is a causative agent of the common cold. The nucleocapsid (N) protein, which is a major structural protein of CoVs, binds to the viral RNA genome to form the virion core and results in the formation of the ribonucleoprotein (RNP) complex. We have solved the crystal structure of the N-terminal domain of HCoV-OC43 N protein (N-NTD) (residues 58 to 195) to a resolution of 2.0Å. The HCoV-OC43 N-NTD is a single domain protein composed of a five-stranded β-sheet core and a long extended loop, similar to that observed in the structures of N-NTDs from other coronaviruses. The positively charged loop of the HCoV-OC43 N-NTD contains a structurally well-conserved positively charged residue, R106. To assess the role of R106 in RNA binding, we undertook a series of site-directed mutagenesis experiments and docking simulations to characterize the interaction between R106 and RNA. The results show that R106 plays an important role in the interaction between the N protein and RNA. In addition, we showed that, in cells transfected with plasmids that encoded the mutant (R106A) N protein and infected with virus, the level of the matrix protein gene was decreased by 7-fold compared to cells that were transfected with the wild-type N protein. This finding suggests that R106, by enhancing binding of the N protein to viral RNA plays a critical role in the viral replication. The results also indicate that the strength of N protein/RNA interactions is critical for HCoV-OC43 replication.
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Affiliation(s)
- I-Jung Chen
- Department of Life Science, National Chung Hsing University, Taichung, Taiwan
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31
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Lo YS, Lin SY, Wang SM, Wang CT, Chiu YL, Huang TH, Hou MH. Oligomerization of the carboxyl terminal domain of the human coronavirus 229E nucleocapsid protein. FEBS Lett 2012. [PMID: 23178926 PMCID: PMC7089611 DOI: 10.1016/j.febslet.2012.11.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
N and N bind by cross‐linking study (View Interaction: 1, 2, 3, 4) ► The role of the C‐terminal tail of the HCoV‐229E N protein in oligomerization. ► A correlation between oligomerization and thermostability. ► The C‐terminal tail peptide interferes with the oligomerization. ► The development of drugs to disrupt the oligomerization of the viral N protein.
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Affiliation(s)
- Yu-Sheng Lo
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 402, Taiwan
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32
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Liang FY, Lin LC, Ying TH, Yao CW, Tang TK, Chen YW, Hou MH. Immunoreactivity characterisation of the three structural regions of the human coronavirus OC43 nucleocapsid protein by Western blot: implications for the diagnosis of coronavirus infection. J Virol Methods 2012; 187:413-20. [PMID: 23174159 PMCID: PMC7112824 DOI: 10.1016/j.jviromet.2012.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2011] [Revised: 10/15/2012] [Accepted: 11/08/2012] [Indexed: 01/25/2023]
Abstract
Previous studies have reported that a prokaryotic-expressed recombinant nucleocapsid protein (NP) is a suitable reagent for the epidemiological screening of coronavirus infection. In this study, soluble recombinant human coronavirus OC43 (HCoV-OC43) NP was produced to examine the antigenicity of the HCoV-OC43 NP of betacoronavirus. Using the purified recombinant NP as an antigen, a polyclonal antibody from rabbit serum with specificity for HCoV-OC43 NP was generated; this antibody reacts specifically with HCoV-OC43 NP and does not cross-react with other human CoV NPs (including those of SARS-CoV and HCoV-229E) by Western blot. Sera from 26 young adults, 17 middle-aged and elderly patients with respiratory infection, and 15 cord blood samples were also tested. Strong reactivity to the NPs of HCoV-OC43 was observed in 96%, 82%, and 93% of the serum samples from the young adults, respiratory patients, and cord blood samples, respectively. To identify the immunoreactivities of the three structural regions of the NP that are recognised by the rabbit polyclonal antibody and human serum, the antigenicities of three protein fragments, including the N-terminal domain (aa 1-173), the central-linker region (aa 174-300), and the C-terminal domain (aa 301-448), were evaluated by Western blot. The rabbit polyclonal antibody demonstrated greater immunoreactivity to the central-linker region and the C-terminal domain than to the N-terminal domain. Three different patterns for the immunoreactivities of the three structural regions of HCoV-OC43 NP were observed in human serum, suggesting variability in the immune responses that occur during HCoV-OC43 infection in humans. The central-linker region of the NP appeared to be the most highly immunoreactive region for all three patterns observed. The goal of this study was to offer insight into the design of diagnostic tools for HCoV infection.
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Affiliation(s)
- Fang-Ying Liang
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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33
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Zhang J, Wang D, Li Y, Zhao Q, Huang A, Zheng J, Chen W. SARS coronavirus nucleocapsid protein monoclonal antibodies developed using a prokaryotic expressed protein. Hybridoma (Larchmt) 2012; 30:481-5. [PMID: 22008077 DOI: 10.1089/hyb.2011.0028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Immunological detection of viruses and their components using monoclonal antibodies (MAbs) is a powerful diagnostic method. Here we report a detailed method for the establishment of MAbs against severe acute respiratory syndrome coronavirus (SARS-CoV). To express and purify the nucleocapsid protein (N protein) of SARS-CoV and generate MAbs against the N protein, gene encoding N protein was separated into two parts according to the prediction of epitopes and cloned into pET32a(+), respectively. Expression of the target proteins were induced by M isopropyl-β-thio-D-galactopyranoside (IPTG) and purified by a single-step affinity chromatography on a Ni-NTA column. BALB/c mice were immunized with the purified recombinant proteins to prepare MAbs by hybridoma technique. The reactivity and specificity of the MAbs were analyzed by ELISA and Western blot analysis. Seven MAbs against N1 and two MAbs against N2 were obtained. In the present study, recombinant SARS-CoV N protein was expressed and purified and nine specific MAbs against SARS-CoV N protein were obtained successfully. This panel of anti-N MAbs may be used as a tool for rapid and specific diagnosis of SARS-CoV.
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Affiliation(s)
- Juan Zhang
- The Clinical Laboratory Center, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
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34
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Cao YL, Wang Y, Guo R, Yang F, Zhang Y, Wang SH, Liu L. Identification and characterization of three novel small interference RNAs that effectively down-regulate the isolated nucleocapsid gene expression of SARS coronavirus. Molecules 2011; 16:1544-58. [PMID: 21317844 PMCID: PMC6259856 DOI: 10.3390/molecules16021544] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 02/09/2011] [Indexed: 01/20/2023] Open
Abstract
Nucleocapsid (N) protein of severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is a major pathological determinant in the host that may cause host cell apoptosis, upregulate the proinflammatory cytokine production, and block innate immune responses. Therefore, N gene has long been thought an ideal target for the design of small interference RNA (siRNA). siRNA is a class of small non-coding RNAs with a size of 21-25nt that functions post-transcriptionally to block targeted gene expression. In this study, we analyzed the N gene coding sequences derived from 16 different isolates, and found that nucleotide deletions and substitutions are mainly located at the first 440nt sequence. Combining previous reports and the above sequence information, we create three novel siRNAs that specifically target the conserved and unexploited regions in the N gene. We show that these siRNAs could effectively and specifically block the isolated N gene expression in mammal cells. Furthermore, we provide evidence to show that N gene can effectively up-regulate M gene mediated interferon β (IFNβ) production, while blocking N gene expression by specific siRNA significantly reduces IFNβ gene expression. Our data indicate that the inhibitory effect of siRNA on the isolated N gene expression might be influenced by the sequence context around the targeted sites.
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Affiliation(s)
| | | | | | | | | | | | - Li Liu
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86 10 65592203; Fax: +86 10 62737136
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35
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SARS-CoV nucleocapsid protein antagonizes IFN-β response by targeting initial step of IFN-β induction pathway, and its C-terminal region is critical for the antagonism. Virus Genes 2010; 42:37-45. [PMID: 20976535 PMCID: PMC7088804 DOI: 10.1007/s11262-010-0544-x] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 10/13/2010] [Indexed: 11/25/2022]
Abstract
Severe acute respiratory syndrome coronavirus (SARS-CoV) encodes a highly basic nucleocapsid (N) protein which can inhibit the synthesis of type I interferon (IFN), but the molecular mechanism of this antagonism remains to be identified. In this study, we demonstrated that the N protein of SARS-CoV could inhibit IFN-beta (IFN-β) induced by poly(I:C) or Sendai virus. However, we found that N protein could not inhibit IFN-β production induced by overexpression of downstream signaling molecules of two important IFN-β induction pathways, toll-like receptor 3 (TLR3)- and RIG-I-like receptors (RLR)-dependent pathways. These results indicate that SARS-CoV N protein targets the initial step, probably the cellular PRRs (pattern recognition receptors)-RNAs-recognition step in the innate immune pathways, to suppress IFN expression responses. In addition, co-immunoprecipitation assays revealed that N protein did not interact with RIG-I or MDA5. Further, an assay using truncated mutants revealed that the C-terminal domain of N protein was critical for its antagonism of IFN induction, and the N deletion mutant impaired for RNA-binding almost completely lost the IFN-β antagonist activity. These results contribute to our further understanding of the pathogenesis of SARS-CoV.
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36
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Huang CY, Hsu YL, Chiang WL, Hou MH. Elucidation of the stability and functional regions of the human coronavirus OC43 nucleocapsid protein. Protein Sci 2010; 18:2209-18. [PMID: 19691129 PMCID: PMC2788276 DOI: 10.1002/pro.225] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Human coronavirus OC43 (HCoV-OC43) is one of the causes of the “common cold” in human during seasons of cold weather. The primary function of the HCoV-OC43 nucleocapsid protein (N protein) is to recognize viral genomic RNA, which leads to ribonucleocapsid formation. Here, we characterized the stability and identified the functional regions of the recombinant HCoV-OC43 N protein. Circular dichroism and fluorescence measurements revealed that the HCoV-OC43 N protein is more highly ordered and stabler than the SARS-CoV N protein previously studied. Surface plasmon resonance (SPR) experiments showed that the affinity of HCoV-OC43 N protein for RNA was approximately fivefold higher than that of N protein for DNA. Moreover, we found that the HCoV-OC43 N protein contains three RNA-binding regions in its N-terminal region (residues 1–173) and central-linker region (residues 174–232 and 233–300). The binding affinities of the truncated N proteins and RNA follow the order: residues 1–173–residues 233–300 > residues 174–232. SPR experiments demonstrated that the C-terminal region (residues 301–448) of HCoV-OC43 N protein lacks RNA-binding activity, while crosslinking and gel filtration analyses revealed that the C-terminal region is mainly involved in the oligomerization of the HCoV-OC43 N protein. This study may benefit the understanding of the mechanism of HCoV-OC43 nucleocapsid formation.
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Affiliation(s)
- Chun-Yu Huang
- Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
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37
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Coronavirus nucleocapsid protein facilitates template switching and is required for efficient transcription. J Virol 2009; 84:2169-75. [PMID: 19955314 DOI: 10.1128/jvi.02011-09] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purified nucleocapsid protein (N protein) from transmissible gastroenteritis virus (TGEV) enhanced hammerhead ribozyme self-cleavage and favored nucleic acid annealing, properties that define RNA chaperones, as previously reported. Several TGEV N-protein deletion mutants were expressed in Escherichia coli and purified, and their RNA binding ability and RNA chaperone activity were evaluated. The smallest N-protein domain analyzed with RNA chaperone activity, facilitating DNA and RNA annealing, contained the central unstructured region (amino acids 117 to 268). Interestingly, N protein and its deletion mutants with RNA chaperone activity enhanced template switching in a retrovirus-derived heterologous system, reinforcing the concept that TGEV N protein is an RNA chaperone that could be involved in template switching. This result is in agreement with the observation that in vivo, N protein is not necessary for TGEV replication, but it is required for efficient transcription.
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38
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Wang SM, Wang CT. APOBEC3G cytidine deaminase association with coronavirus nucleocapsid protein. Virology 2009; 388:112-20. [PMID: 19345973 PMCID: PMC7103413 DOI: 10.1016/j.virol.2009.03.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 01/09/2009] [Accepted: 03/10/2009] [Indexed: 01/20/2023]
Abstract
We previously reported that replacing HIV-1 nucleocapsid (NC) domain with SARS-CoV nucleocapsid (N) residues 2–213, 215–421, or 234–421 results in efficient virus-like particle (VLP) production at a level comparable to that of wild-type HIV-1. In this study we demonstrate that these chimeras are capable of packaging large amounts of human APOBEC3G (hA3G), and that an HIV-1 Gag chimera containing the carboxyl-terminal half of human coronavirus 229E (HCoV-229E) N as a substitute for NC is capable of directing VLP assembly and efficiently packaging hA3G. When co-expressed with SARS-CoV N and M (membrane) proteins, hA3G was efficiently incorporated into SARS-CoV VLPs. Data from GST pull-down assays suggest that the N sequence involved in N–hA3G interactions is located between residues 86 and 302. Like HIV-1 NC, the SARS-CoV or HCoV-229E N-associated with hA3G depends on the presence of RNA, with the first linker region essential for hA3G packaging into both HIV-1 and SARS-CoV VLPs. The results raise the possibility that hA3G is capable of associating with different species of viral structural proteins through a potentially common, RNA-mediated mechanism.
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Affiliation(s)
- Shui-Mei Wang
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan
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39
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Multiple nucleic acid binding sites and intrinsic disorder of severe acute respiratory syndrome coronavirus nucleocapsid protein: implications for ribonucleocapsid protein packaging. J Virol 2008; 83:2255-64. [PMID: 19052082 DOI: 10.1128/jvi.02001-08] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The nucleocapsid protein (N) of the severe acute respiratory syndrome coronavirus (SARS-CoV) packages the viral genomic RNA and is crucial for viability. However, the RNA-binding mechanism is poorly understood. We have shown previously that the N protein contains two structural domains--the N-terminal domain (NTD; residues 45 to 181) and the C-terminal dimerization domain (CTD; residues 248 to 365)--flanked by long stretches of disordered regions accounting for almost half of the entire sequence. Small-angle X-ray scattering data show that the protein is in an extended conformation and that the two structural domains of the SARS-CoV N protein are far apart. Both the NTD and the CTD have been shown to bind RNA. Here we show that all disordered regions are also capable of binding to RNA. Constructs containing multiple RNA-binding regions showed Hill coefficients greater than 1, suggesting that the N protein binds to RNA cooperatively. The effect can be explained by the "coupled-allostery" model, devised to explain the allosteric effect in a multidomain regulatory system. Although the N proteins of different coronaviruses share very low sequence homology, the physicochemical features described above may be conserved across different groups of Coronaviridae. The current results underscore the important roles of multisite nucleic acid binding and intrinsic disorder in N protein function and RNP packaging.
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40
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Severe acute respiratory syndrome coronavirus nucleocapsid protein confers ability to efficiently produce virus-like particles when substituted for the human immunodeficiency virus nucleocapsid domain. J Biomed Sci 2008; 15:719-29. [PMID: 18592403 PMCID: PMC7088652 DOI: 10.1007/s11373-008-9265-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Accepted: 06/17/2008] [Indexed: 12/14/2022] Open
Abstract
We replaced the HIV-1 nucleocapsid (NC) domain with different N-coding sequences to test SARS-CoV nucleocapsid (N) self-interaction capacity, and determined the capabilities of each chimera to direct virus-like particle (VLP) assembly. Analysis results indicate that the replacement of NC with the carboxyl-terminal half of the SARS-CoV N resulted in the production of wild type (wt)-level virus-like particles (VLPs) with the density of a wt HIV-1 particle. When co-expressed with SARS-CoV N, chimeras containing the N carboxyl-terminal half sequence efficiently packaged N. However, the same was not true for the chimera bearing the N amino-terminal half sequence, despite its production of substantial amounts of VLPs. According to further analysis, HIV-1 NC replacement with N residues 2–213, 215–421, or 234–421 resulted in efficient VLP production at levels comparable to that of wt HIV-1, but replacement with residues 215–359, 302–421, 2–168, or 2–86 failed to restore VLP production to wild-type levels. The results suggest that the domain conferring the ability to direct VLP assembly and release in SARS-CoV N is largely contained between residues 168 and 421.
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41
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Chen CY, Chang CK, Chang YW, Sue SC, Bai HI, Riang L, Hsiao CD, Huang TH. Structure of the SARS coronavirus nucleocapsid protein RNA-binding dimerization domain suggests a mechanism for helical packaging of viral RNA. J Mol Biol 2007; 368:1075-86. [PMID: 17379242 PMCID: PMC7094638 DOI: 10.1016/j.jmb.2007.02.069] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 02/15/2007] [Accepted: 02/17/2007] [Indexed: 11/22/2022]
Abstract
Coronavirus nucleocapsid proteins are basic proteins that encapsulate viral genomic RNA to form part of the virus structure. The nucleocapsid protein of SARS-CoV is highly antigenic and associated with several host-cell interactions. Our previous studies using nuclear magnetic resonance revealed the domain organization of the SARS-CoV nucleocapsid protein. RNA has been shown to bind to the N-terminal domain (NTD), although recently the C-terminal half of the protein has also been implicated in RNA binding. Here, we report that the C-terminal domain (CTD), spanning residues 248-365 (NP248-365), had stronger nucleic acid-binding activity than the NTD. To determine the molecular basis of this activity, we have also solved the crystal structure of the NP248-365 region. Residues 248-280 form a positively charged groove similar to that found in the infectious bronchitis virus (IBV) nucleocapsid protein. Furthermore, the positively charged surface area is larger in the SARS-CoV construct than in the IBV. Interactions between residues 248-280 and the rest of the molecule also stabilize the formation of an octamer in the asymmetric unit. Packing of the octamers in the crystal forms two parallel, basic helical grooves, which may be oligonucleotide attachment sites, and suggests a mechanism for helical RNA packaging in the virus.
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Affiliation(s)
- Chun-Yuan Chen
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan, ROC
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42
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Kim H, Jung S, Kim S, Suh I, Kim WJ, Jung J, Yuk JS, Kim Y, Ha K. High-throughput analysis of mumps virus and the virus-specific monoclonal antibody on the arrays of a cationic polyelectrolyte with a spectral SPR biosensor. Proteomics 2007; 6:6426-32. [PMID: 17111437 PMCID: PMC7167642 DOI: 10.1002/pmic.200600432] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
We investigated the potential use of a spectral surface plasmon resonance (SPR) biosensor in a high‐throughput analysis of mumps virus and a mumps virus‐specific mAb on the arrays of a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA). The PDDA surface was constructed by electrostatic adsorption of the polyelectrolyte onto a monolayer of 11‐mercaptoundecanoic acid (MUA). Poly‐l‐lysine was also adsorbed onto the MUA monolayer and compared with the PDDA surface in the capacity of mumps virus immobilization. The PDDA surface showed a higher adsorption of mumps virus than the poly‐l‐lysine surface. The SPR signal caused by the virus binding onto the PDDA surface was proportional to the concentration of mumps virus from 0.5 × 105 to 14 × 105 pfu/mL. The surface structure of the virus arrays was visualized by atomic force microscopy. Then, a dose‐dependent increase in the SPR signal was observed when various concentrations of the antimumps virus antibody in buffer or human serum were applied to the virus arrays, and their interaction was specific. Thus, it is likely that the spectral SPR biosensor based on the cationic polyelectrolyte surface may provide an efficient system for a high‐throughput analysis of intact virus and serodiagnosis of infectious diseases.
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Affiliation(s)
- Hyun‐Soo Kim
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Se‐Hui Jung
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Sang‐Hyun Kim
- Department of Microbiology, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - In‐Bum Suh
- Department of Laboratory Medicine, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Woo Jin Kim
- Department of Internal Medicine, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Jae‐Wan Jung
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Jong seol Yuk
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Young‐Myeong Kim
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
| | - Kwon‐Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University College of Medicine, Chuncheon, Kangwon‐do, Korea
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43
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Bussmann BM, Reiche S, Jacob LH, Braun JM, Jassoy C. Antigenic and cellular localisation analysis of the severe acute respiratory syndrome coronavirus nucleocapsid protein using monoclonal antibodies. Virus Res 2006; 122:119-26. [PMID: 16920216 PMCID: PMC7114340 DOI: 10.1016/j.virusres.2006.07.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 07/07/2006] [Accepted: 07/12/2006] [Indexed: 01/19/2023]
Abstract
A member of the family of coronaviruses has previously been identified as the cause of the severe acute respiratory syndrome (SARS). In this study, several monoclonal antibodies against the nucleocapsid protein have been generated to examine distribution of the nucleocapsid in virus-infected cells and to study antigenic regions of the protein. Confocal microscopic analysis identified nucleocapsids packaged in vesicles in the perinuclear area indicating viral synthesis at the endoplasmic reticulum and Golgi apparatus. The monoclonal antibodies bound to the central and carboxyterminal half of the nucleocapsid protein indicating prominent exposure and immunogenicity of this part of the protein. Antibodies recognised both linear and conformational epitopes. Predictions of antigenicity using mathematical modelling based on hydrophobicity analysis of SARS nucleoprotein could not be confirmed fully. Antibody binding to discontinuous peptides provides evidence that amino acids 274–283 and 373–382 assemble to a structural unit particularly rich in basic amino acids. In addition, amino acids 286–295, 316–325 and 361–367 that represent the epitope recognised by monoclonal antibody 6D11C1 converge indicating a well-structured C-terminal region of the SARS virus nucleocapsid protein and functional relationship of the peptide regions involved. Alternatively, dimerisation of the nucleocapsid protein may result in juxtaposition of the amino acid sequences 316–325 and 361–367 on one nucleoprotein molecule to amino acid 286–295 on the second peptide. The monoclonal antibodies will be available to assess antigenicity and immunological variabilities between different SARS CoV strains.
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Affiliation(s)
- Bianca M. Bussmann
- Institute of Virology, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
| | - Sven Reiche
- Institute of Virology, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
| | - Lotta H. Jacob
- Institute of Virology, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
| | - Jan Matthias Braun
- Institute of Clinical Immunology and Transfusion Medicine (IKIT) and Interdisciplinary Centre of Clinical Research (IZKF), Faculty of Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
| | - Christian Jassoy
- Institute of Virology, University of Leipzig, Johannisallee 30, 04103 Leipzig, Germany
- Corresponding author. Tel.: +49 341 9714314; fax: +49 341 9714309.
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44
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Das D, Suresh MR. Copious production of SARS-CoV nucleocapsid protein employing codon optimized synthetic gene. J Virol Methods 2006; 137:343-6. [PMID: 16904198 PMCID: PMC7112773 DOI: 10.1016/j.jviromet.2006.06.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 04/04/2006] [Accepted: 06/29/2006] [Indexed: 12/15/2022]
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein (NP) is one of the predominant antigenic protein and the most abundant shed antigen throughout the SARS-CoV infection. This feature makes it a suitable molecular target for diagnostic applications. In this study the full length codon optimized NP gene and its subfragment gene segment was cloned in a bacterial expression vector. The full length NP could be expressed in E. coli at very high level within inclusion bodies. The inclusion bodies were successfully solubilized, purified under denaturing conditions employing IMAC column and refolded. The non-glycosylated NP was used to immunize mice for hybridoma development. The polyclonal antiserum from animals immunized with this recombinant NP protein was found to specifically recognize the NP and its subfragments, thus demonstrating the immunogenic nature of the recombinant protein. The NP antigen or a subfragment could be useful for developing a sensitive serum diagnostic assay to monitor SARS-CoV outbreaks by detecting the early human anti-SARS antibodies. In addition, the availability of the NP fragments could facilitate epitope mapping of anti-NP monoclonals for identifying suitable sandwich pairs.
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MESH Headings
- Animals
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/immunology
- Antigens, Viral/biosynthesis
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Antigens, Viral/isolation & purification
- Cloning, Molecular
- Codon/genetics
- Coronavirus Nucleocapsid Proteins
- Electrophoresis, Polyacrylamide Gel
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Genes, Synthetic
- Inclusion Bodies
- Mice
- Nucleocapsid Proteins/biosynthesis
- Nucleocapsid Proteins/genetics
- Nucleocapsid Proteins/immunology
- Nucleocapsid Proteins/isolation & purification
- Recombinant Proteins/biosynthesis
- Severe acute respiratory syndrome-related coronavirus/genetics
- Severe acute respiratory syndrome-related coronavirus/immunology
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45
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Yan X, Hao Q, Mu Y, Timani KA, Ye L, Zhu Y, Wu J. Nucleocapsid protein of SARS-CoV activates the expression of cyclooxygenase-2 by binding directly to regulatory elements for nuclear factor-kappa B and CCAAT/enhancer binding protein. Int J Biochem Cell Biol 2006; 38:1417-28. [PMID: 16546436 PMCID: PMC7108415 DOI: 10.1016/j.biocel.2006.02.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2005] [Revised: 01/17/2006] [Accepted: 02/07/2006] [Indexed: 02/02/2023]
Abstract
SARS-associated coronavirus (SARS-CoV) causes inflammation and damage to the lungs resulting in severe acute respiratory syndrome. To evaluate the molecular mechanisms behind this event, we investigated the roles of SARS-CoV proteins in regulation of the proinflammatory factor, cyclooxygenase-2 (COX-2). Individual viral proteins were tested for their abilities to regulate COX-2 gene expression. Results showed that the COX-2 promoter was activated by the nucleocapsid (N) protein in a concentration-dependent manner. Western blot analysis indicated that N protein was sufficient to stimulate the production of COX-2 protein in mammalian cells. COX-2 promoter mutations suggested that activation of COX-2 transcription depended on two regulatory elements, a nuclear factor-kappa B (NF-κB) binding site, and a CCAAT/enhancer binding protein (C/EBP) binding site. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) demonstrated that SARS-CoV N protein bound directly to these regulatory sequences. Protein mutation analysis revealed that a Lys-rich motif of N protein acted as a nuclear localization signal and was essential for the activation of COX-2. In addition, a Leu-rich motif was found to be required for the N protein function. A sequence of 68 residuals was identified as a potential DNA-binding domain essential for activating COX-2 expression. We propose that SARS-CoV N protein causes inflammation of the lungs by activating COX-2 gene expression by binding directly to the promoter resulting in inflammation through multiple COX-2 signaling cascades.
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Affiliation(s)
| | | | | | | | | | | | - Jianguo Wu
- Corresponding author. Tel.: +86 27 68754979; fax: +86 27 68754592.
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Chang CK, Sue SC, Yu TH, Hsieh CM, Tsai CK, Chiang YC, Lee SJ, Hsiao HH, Wu WJ, Chang WL, Lin CH, Huang TH. Modular organization of SARS coronavirus nucleocapsid protein. J Biomed Sci 2005; 13:59-72. [PMID: 16228284 PMCID: PMC7089556 DOI: 10.1007/s11373-005-9035-9] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Accepted: 09/12/2005] [Indexed: 12/25/2022] Open
Abstract
The SARS-CoV nucleocapsid (N) protein is a major antigen in severe acute respiratory syndrome. It binds to the viral RNA genome and forms the ribonucleoprotein core. The SARS-CoV N protein has also been suggested to be involved in other important functions in the viral life cycle. Here we show that the N protein consists of two non-interacting structural domains, the N-terminal RNA-binding domain (RBD) (residues 45-181) and the C-terminal dimerization domain (residues 248-365) (DD), surrounded by flexible linkers. The C-terminal domain exists exclusively as a dimer in solution. The flexible linkers are intrinsically disordered and represent potential interaction sites with other protein and protein-RNA partners. Bioinformatics reveal that other coronavirus N proteins could share the same modular organization. This study provides information on the domain structure partition of SARS-CoV N protein and insights into the differing roles of structured and disordered regions in coronavirus nucleocapsid proteins.
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Affiliation(s)
- Chung-ke Chang
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Shih-Che Sue
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Tsan-hung Yu
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Chiu-Min Hsieh
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Cheng-Kun Tsai
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
- Department of Physics, National Taiwan Normal University, Taipei, Taiwan, ROC
| | - Yen-Chieh Chiang
- Department of Agronomy, National Taiwan University, Taipei, Taiwan, ROC
| | - Shin-jye Lee
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Hsin-hao Hsiao
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Wen-Jin Wu
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Wei-Lun Chang
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan, ROC
| | - Tai-huang Huang
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, ROC
- Department of Physics, National Taiwan Normal University, Taipei, Taiwan, ROC
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47
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Current Awareness on Comparative and Functional Genomics. Comp Funct Genomics 2005. [PMCID: PMC2447491 DOI: 10.1002/cfg.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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