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Small-Molecule HIV Entry Inhibitors Targeting gp120 and gp41. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1366:27-43. [DOI: 10.1007/978-981-16-8702-0_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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DNA Quadruplex-Based Inhibitor With Flexible Fragments at the 3' Terminal Shows Enhanced Anti-HIV-1 Fusion Activity. J Pharm Sci 2019; 108:2243-2246. [PMID: 30797782 DOI: 10.1016/j.xphs.2019.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/14/2019] [Accepted: 02/08/2019] [Indexed: 12/20/2022]
Abstract
Chemically optimizing the molecular structure of aptamers may enhance properties such as biological activity or metabolic stability. DNA quadruplex-based HIV-1 fusion inhibitors were found to interact with HIV-1 surface glycoprotein in aptamer mode. In this work, a series of quadruplex-based HIV-1 fusion inhibitors with flexible oligodeoxynucleotide fragments at the 3' terminal was discovered. The flexible extension did not greatly influence quadruplex formation at the 5'-end. Increasing the length of the flexible fragment may increase antifusion activity. Compared with a traditional inhibitor, d(5'TGGGAG3')4, these novel inhibitors showed enhanced interaction with HIV-1 glycoproteins gp120 and gp41, which increased inhibition of 6-helical bundle formation during the course of virus fusion. These inhibitors also showed improved stability, compared with natural oligodeoxynucleotide. This work may inform the design of anti-HIV-1 DNA helix-based inhibitors with new structures or mechanisms.
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Tang Y, Han Z, Guo J, Tian Y, Liu K, Xu L. Synthesis, biophysical characterization, and anti-HIV-1 fusion activity of DNA helix-based inhibitors with a p-benzyloxyphenyl substituent at the 5'-nucleobase site. Bioorg Med Chem Lett 2018; 28:1842-1845. [PMID: 29680665 DOI: 10.1016/j.bmcl.2018.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 11/17/2022]
Abstract
DNA helix-based HIV-1 fusion inhibitors have been discovered as potent drug candidates. Introduction of hydrophobic groups to a nucleobase provides an opportunity to design inhibitors with novel structures and mechanisms of action. In this work, two novel nucleoside analogues (1 and 2) were synthesized and incorporated into four DNA duplex- and quadruplex-based inhibitors. All the molecules showed anti-HIV-1 fusion activity. The effect of the p-benzyloxyphenyl group and the attached linker on the helix formation and thermal stability were fully compared and discussed. Surface plasmon resonance analysis further indicated that inhibitors with the same DNA helix may still have variable reaction targets, mainly attributed to the different hydrophobic modifications.
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Affiliation(s)
- Yongjia Tang
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| | - Zeye Han
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| | - Jiamei Guo
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yangli Tian
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China
| | - Keliang Liu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China.
| | - Liang Xu
- State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850, China.
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4
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Xu L, Zhang T, Xu X, Chong H, Lai W, Jiang X, Wang C, He Y, Liu K. DNA Triplex-Based Complexes Display Anti-HIV-1-Cell Fusion Activity. Nucleic Acid Ther 2016; 25:219-25. [PMID: 26192705 DOI: 10.1089/nat.2015.0535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
DNA triplexes with hydrophobic modifications were designed and evaluated for their activity as inhibitors of the cell fusion of human immunodeficiency virus type 1 (HIV-1). Triplex inhibitors displayed low micromolar activities in the cell-cell fusion assay and nanomolar activities in the anti-HIV-1 pseudovirus test. Helix structure and the presence of sufficient numbers of hydrophobic regions were essential for the antifusion activity. Results from native polyacrylamide gel electrophoresis and a fluorescent resonance energy transfer-based inhibitory assay indicated that these triplexes may interact with the primary pocket at the glycoprotein 41 (gp41) N-heptad repeat, thereby inhibiting formation of the HIV-1 gp41 6-helical bundle. Triplex-based complexes may represent a novel category of HIV-1 inhibitors in anti-HIV-1 drug discovery.
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Affiliation(s)
- Liang Xu
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Tao Zhang
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Xiaoyu Xu
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Huihui Chong
- 2 Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Wenqing Lai
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Xifeng Jiang
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Chao Wang
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
| | - Yuxian He
- 2 Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Keliang Liu
- 1 State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Institute of Pharmacology and Toxicology , Beijing, China
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5
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Lu L, Yu F, Cai L, Debnath AK, Jiang S. Development of Small-molecule HIV Entry Inhibitors Specifically Targeting gp120 or gp41. Curr Top Med Chem 2016; 16:1074-90. [PMID: 26324044 PMCID: PMC4775441 DOI: 10.2174/1568026615666150901114527] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 05/17/2015] [Accepted: 05/27/2015] [Indexed: 12/31/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein surface subunit gp120 and transmembrane subunit gp41 play important roles in HIV-1 entry, thus serving as key targets for the development of HIV-1 entry inhibitors. T20 peptide (enfuvirtide) is the first U.S. FDA-approved HIV entry inhibitor; however, its clinical application is limited by the lack of oral availability. Here, we have described the structure and function of the HIV-1 gp120 and gp41 subunits and reviewed advancements in the development of small-molecule HIV entry inhibitors specifically targeting these two Env glycoproteins. We then compared the advantages and disadvantages of different categories of HIV entry inhibitor candidates and further predicted the future trend of HIV entry inhibitor development.
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Affiliation(s)
| | | | | | | | - Shibo Jiang
- Key Laboratory of Medical Molecular Virology of MOE/MOH, Shanghai Medical College, Fudan University, 130 Dong An Road, Building #13, Shanghai 200032, China.
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Wang Y, Huang C, Kang Y. Incorporation of ligand–receptor binding‐site models and transistor‐based sensors for resolving dissociation constants and number of binding sites. IET Nanobiotechnol 2014; 8:10-7. [DOI: 10.1049/iet-nbt.2013.0031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Yu‐Lin Wang
- Institute of Nanoengineering and MicrosystemsNational Tsing Hua UniversityHsinchu 30013Taiwan
| | - Chih‐Cheng Huang
- Institute of Nanoengineering and MicrosystemsNational Tsing Hua UniversityHsinchu 30013Taiwan
| | - Yen‐Wen Kang
- Institute of Nanoengineering and MicrosystemsNational Tsing Hua UniversityHsinchu 30013Taiwan
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7
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Bao C, Pähler G, Geil B, Janshoff A. Optical Fusion Assay Based on Membrane-Coated Spheres in a 2D Assembly. J Am Chem Soc 2013; 135:12176-9. [DOI: 10.1021/ja404071z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chunxiao Bao
- Institute of Physical Chemistry, Georg-August-University, Tammannstrasse 6, 37077 Göttingen,
Germany
| | - Gesa Pähler
- Institute of Physical Chemistry, Georg-August-University, Tammannstrasse 6, 37077 Göttingen,
Germany
| | - Burkhard Geil
- Institute of Physical Chemistry, Georg-August-University, Tammannstrasse 6, 37077 Göttingen,
Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, Georg-August-University, Tammannstrasse 6, 37077 Göttingen,
Germany
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8
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NMR-assisted computational studies of peptidomimetic inhibitors bound in the hydrophobic pocket of HIV-1 glycoprotein 41. J Comput Aided Mol Des 2013; 27:569-82. [PMID: 23893342 DOI: 10.1007/s10822-013-9662-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 06/30/2013] [Indexed: 10/26/2022]
Abstract
Due to the inherently flexible nature of a protein-protein interaction surface, it is difficult both to inhibit the association with a small molecule, and to predict how it might bind to the surface. In this study, we have examined small molecules that mediate the interaction between a WWI motif on the C-helix of HIV-1 glycoprotein-41 (gp41) and a deep hydrophobic pocket contained in the interior N-helical trimer. Association between these two components of gp41 leads to virus-cell and cell-cell fusion, which could be abrogated in the presence of an inhibitor that binds tightly in the pocket. We have studied a comprehensive combinatorial library of α-helical peptidomimetics, and found that compounds with strongly hydrophobic side chains had the highest affinity. Computational docking studies produced multiple possible binding modes due to the flexibility of both the binding site and the peptidomimetic compounds. We applied a transferred paramagnetic relaxation enhancement experiment to two selected members of the library, and showed that addition of a few experimental constraints enabled definitive identification of unique binding poses. Computational docking results were extremely sensitive to side chain conformations, and slight variations could preclude observation of the experimentally validated poses. Different receptor structures were required for docking simulations to sample the correct pose for the two compounds. The study demonstrated the sensitivity of predicted poses to receptor structure and indicated the importance of experimental verification when docking to a malleable protein-protein interaction surface.
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Huang CC, Lee GY, Chyi JI, Cheng HT, Hsu CP, Hsu YR, Hsu CH, Huang YF, Sun YC, Chen CC, Li SS, Andrew Yeh J, Yao DJ, Ren F, Wang YL. AlGaN/GaN high electron mobility transistors for protein-peptide binding affinity study. Biosens Bioelectron 2013; 41:717-22. [PMID: 23102432 PMCID: PMC7157921 DOI: 10.1016/j.bios.2012.09.066] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/14/2012] [Accepted: 09/27/2012] [Indexed: 01/09/2023]
Abstract
Antibody-immobilized AlGaN/GaN high electron mobility transistors (HEMTs) were used to detect a short peptide consisting of 20 amino acids. One-binding-site model and two-binding-site model were used for the analysis of the electrical signals, revealing the number of binding sites on an antibody and the dissociation constants between the antibody and the short peptide. In the binding-site models, the surface coverage ratio of the short peptide on the sensor surface is relevant to the electrical signals resulted from the peptide-antibody binding on the HEMTs. Two binding sites on an antibody were observed and two dissociation constants, 4.404×10(-11) M and 1.596×10(-9) M, were extracted from the binding-site model through the analysis of the surface coverage ratio of the short peptide on the sensor surface. We have also shown that the conventional method to extract the dissociation constant from the linear regression of curve-fitting with Langmuir isotherm equation may lead to an incorrect information if the receptor has more than one binding site for the ligand. The limit of detection (LOD) of the sensor observed in the experimental result (~10 pM of the short peptide) is very close to the LOD (around 2.7-3.4 pM) predicted from the value of the smallest dissociation constants. The sensitivity of the sensor is not only dependent on the transistors, but also highly relies on the affinity of the ligand-receptor pair. The results demonstrate that the AlGaN/GaN HEMTs cannot only be used for biosensors, but also for the biological affinity study.
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Affiliation(s)
- Chih-Cheng Huang
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - Geng-Yen Lee
- Department of Electrical engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan, ROC
| | - Jen-Inn Chyi
- Department of Electrical engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan, ROC
| | - Hui-Teng Cheng
- Department of Nephrology, National Taiwan University Hospital, Hsinchu branch, Hsinchu 300, Taiwan, ROC
| | - Chen-Pin Hsu
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - You-Ren Hsu
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - Chia-Hsien Hsu
- Division of Medical Engineering, National Health Research Institutes, MiaoLi, Taiwan, ROC
| | - Yu-Fen Huang
- Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu 300, Taiwan, ROC
| | - Yuh-Chang Sun
- Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu 300, Taiwan, ROC
| | - Chih-Chen Chen
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - Sheng-Shian Li
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - J. Andrew Yeh
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - Da-Jeng Yao
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
| | - Fan Ren
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Yu-Lin Wang
- Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu, 300, Taiwan, ROC
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Approaches for identification of HIV-1 entry inhibitors targeting gp41 pocket. Viruses 2013; 5:127-49. [PMID: 23344560 PMCID: PMC3564113 DOI: 10.3390/v5010127] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 01/03/2013] [Accepted: 01/03/2013] [Indexed: 01/08/2023] Open
Abstract
The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR) domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon), was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD), it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of production. Thus, development of small molecule compounds targeting the gp41 pocket with oral availability has been promoted. This review describes the main approaches for identification of HIV fusion/entry inhibitors targeting the gp41 pocket and summarizes the latest progress in developing these inhibitors as a new class of anti-HIV drugs.
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11
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Whitby LR, Boyle KE, Cai L, Yu X, Gochin M, Boger DL. Discovery of HIV fusion inhibitors targeting gp41 using a comprehensive α-helix mimetic library. Bioorg Med Chem Lett 2012; 22:2861-5. [PMID: 22424973 PMCID: PMC3321071 DOI: 10.1016/j.bmcl.2012.02.062] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 02/21/2012] [Indexed: 11/19/2022]
Abstract
The evaluation of a comprehensive α-helix mimetic library for binding the gp41 NHR hydrophobic pocket recognizing an intramolecular CHR α-helix provided a detailed depiction of structural features required for binding and led to the discovery of small molecule inhibitors (K(i) 0.6-1.3 μM) that not only match or exceed the potency of those disclosed over the past decade, but that also exhibit effective activity in a cell-cell fusion assay (IC(50) 5-8 μM).
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Affiliation(s)
- Landon R. Whitby
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037
| | - Kristopher E. Boyle
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037
| | - Lifeng Cai
- Department of Basic Sciences, Touro University – California, 1310 Club Drive, Mare Island, Vallejo, CA 94592
| | - Xiaoqian Yu
- Department of Basic Sciences, Touro University – California, 1310 Club Drive, Mare Island, Vallejo, CA 94592
| | - Miriam Gochin
- Department of Basic Sciences, Touro University – California, 1310 Club Drive, Mare Island, Vallejo, CA 94592
| | - Dale L. Boger
- Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N Torrey Pines Rd, La Jolla, CA 92037
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12
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Cai L, Jiang S. Development of peptide and small-molecule HIV-1 fusion inhibitors that target gp41. ChemMedChem 2011; 5:1813-24. [PMID: 20845360 DOI: 10.1002/cmdc.201000289] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
It has been 25 years since the development of the first efficient HIV-1/AIDS treatment. Scientists now know more about the HIV-1 infection life cycle, and more than 30 antiretroviral drugs have been developed, including HIV-1 fusion inhibitors. Fundamental work was begun in the early 1990s and led to the development of a novel class of anti-HIV-1 drugs, culminating in a peptide known as T20, which is currently the only HIV-1 fusion inhibitor approved by the US Food and Drug Administration. However, more work needs to be done to perfect the development of peptide and small-molecule HIV fusion inhibitors, particularly those that target gp41. Herein we present a brief overview of the development of this class of anti-HIV-1 drug by focusing on the achievements, challenges, and lessons learned. We cite hallmark studies of the past and comment on future drug development.
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Affiliation(s)
- Lifeng Cai
- Department of Medicinal Chemistry, Beijing Institute of Pharmacology & Toxicology, 27 Taiping Road, Haidian District, Beijing 100850, China.
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13
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Pan C, Liu S, Jiang S. HIV-1 gp41 Fusion Intermediate: A Target for HIV Therapeutics. J Formos Med Assoc 2010; 109:94-105. [DOI: 10.1016/s0929-6646(10)60029-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 09/25/2009] [Accepted: 09/25/2009] [Indexed: 11/28/2022] Open
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Oishi S, Watanabe K, Ito S, Tanaka M, Nishikawa H, Ohno H, Shimane K, Izumi K, Sakagami Y, Kodama EN, Matsuoka M, Asai A, Fujii N. Affinity selection and sequence-activity relationships of HIV-1 membrane fusion inhibitors directed at the drug-resistant variants. MEDCHEMCOMM 2010. [DOI: 10.1039/c0md00091d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Nishikawa H, Oishi S, Fujita M, Watanabe K, Tokiwa R, Ohno H, Kodama E, Izumi K, Kajiwara K, Naitoh T, Matsuoka M, Otaka A, Fujii N. Identification of minimal sequence for HIV-1 fusion inhibitors. Bioorg Med Chem 2008; 16:9184-7. [DOI: 10.1016/j.bmc.2008.09.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 08/29/2008] [Accepted: 09/05/2008] [Indexed: 11/26/2022]
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16
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Hou Y, Gochin M. Artificial Ion Channel Biosensor in Human Immunodeficiency Virus gp41 Drug Sensing. Anal Chem 2008; 80:5924-9. [DOI: 10.1021/ac800511n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yanxia Hou
- Department of Basic Sciences, Touro University-California, Vallejo, California 94592, and Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94143
| | - Miriam Gochin
- Department of Basic Sciences, Touro University-California, Vallejo, California 94592, and Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California 94143
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Xu W, Taylor JW. A Template-assembled Model of the N-peptide Helix Bundle from HIV-1 Gp-41 with High Affinity for C-peptide. Chem Biol Drug Des 2007; 70:319-28. [DOI: 10.1111/j.1747-0285.2007.00562.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Cai L, Gochin M. A novel fluorescence intensity screening assay identifies new low-molecular-weight inhibitors of the gp41 coiled-coil domain of human immunodeficiency virus type 1. Antimicrob Agents Chemother 2007; 51:2388-95. [PMID: 17452484 PMCID: PMC1913228 DOI: 10.1128/aac.00150-07] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 03/16/2007] [Accepted: 04/13/2007] [Indexed: 11/20/2022] Open
Abstract
A metallopeptide-based fluorescence assay has been designed for the detection of small-molecule inhibitors of human immunodeficiency virus type 1 gp41, the viral protein involved in membrane fusion. The assay involves two peptides representing the inner N-terminal-heptad-repeat (HR1) coiled coil and the outer C-terminal-heptad-repeat (HR2) helical domains of the gp41 six-helix bundle which forms prior to fusion. The two peptides span a hydrophobic pocket previously defined in the literature. The HR1 peptide is modified with a metal-ligated dye complex, which maintains structural integrity and permits association with a fluorophore-labeled HR2 peptide to be followed by fluorescence quenching. Compounds able to disrupt six-helix bundle formation can act as fusion inhibitors, and we show that they can be detected in the assay from an increase in the fluorescence that is correlated with the potency of the compound. Assay optimization and validation have resulted in a simple quantitative competitive inhibition assay for fusion inhibitors that bind in the hydrophobic pocket. The assay has an assay quality factor (Z') of 0.88 and can rank order inhibitors at 10 microM concentration with K(i)s in the range of 0.2 microM to 30 microM, an ideal range for drug discovery. Screening of a small peptidomimetic library has yielded three new low-molecular-weight gp41 inhibitors. In vitro syncytium inhibition assays confirmed that the compounds inhibited cell-cell fusion in the low micromolar range. These lead compounds provide a new molecular scaffold for the development of fusion inhibitors.
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Affiliation(s)
- Lifeng Cai
- Department of Basic Sciences, Touro University - California, Vallejo, California 94592, USA
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19
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Berezin MY, Lee H, Akers W, Achilefu S. Near infrared dyes as lifetime solvatochromic probes for micropolarity measurements of biological systems. Biophys J 2007; 93:2892-9. [PMID: 17573433 PMCID: PMC1989699 DOI: 10.1529/biophysj.107.111609] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The polarity of biological mediums controls a host of physiological processes such as digestion, signaling, transportation, metabolism, and excretion. With the recent widespread use of near-infrared (NIR) fluorescent dyes for biological imaging of cells and living organisms, reporting medium polarity with these dyes would provide invaluable functional information in addition to conventional optical imaging parameters. Here, we report a new approach to determine polarities of macro- and microsystems for in vitro and potential in vivo applications using NIR polymethine molecular probes. Unlike the poor solvatochromic response of NIR dyes in solvents with diverse polarity, their fluorescence lifetimes are highly sensitive, increasing by a factor of up to 8 on moving from polar to nonpolar mediums. We also established a correlation between fluorescence lifetime and solvent orientation polarizability and developed a lifetime polarity index for determining the polarity of complex systems, including micelles and albumin binding sites. Because of the importance of medium polarity in molecular, cellular, and biochemical processes and the significance of reduced autofluorescence and deep tissue penetration of light in the NIR region, the findings reported herein represent an important advance toward using NIR molecular probes to measure the polarity of complex biological systems in vitro and in vivo.
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Affiliation(s)
- Mikhail Y Berezin
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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20
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Dams G, Van Acker K, Gustin E, Vereycken I, Bunkens L, Holemans P, Smeulders L, Clayton R, Ohagen A, Hertogs K. A Time-Resolved Fluorescence Assay to Identify Small-Molecule Inhibitors of HIV-1 Fusion. ACTA ACUST UNITED AC 2007; 12:865-74. [PMID: 17644771 DOI: 10.1177/1087057107304645] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fusion of host cell and human immunodeficiency virus type 1 (HIV-1) membranes is mediated by the 2 “heptad-repeat” regions of the viral gp41 protein. The collapse of the C-terminal heptad-repeat regions into the hydrophobic grooves of a coiled-coil formed by the corresponding homotrimeric N-terminal heptad-repeat regions generates a stable 6-helix bundle. This brings viral and cell membranes together for membrane fusion, facilitating viral entry. The authors developed an assay based on soluble peptides derived from the gp41 N-terminal heptad-repeat region (IQN36) as well as from the C-terminal region (C34). Both peptides were labeled with fluorophores, IQN36 with allophycocyanin (APC) and C34 with the lanthanide europium (Eu3+). Formation of the 6-helix bundle brings both fluorophores in close proximity needed for Förster resonance energy transfer (FRET). Compounds that interfere with binding of C34-Eu with IQN36-APC suppress the FRET signal. The assay was validated with various peptides and small molecules, and quenching issues were addressed. Evaluation of a diversified compound collection in a high-throughput screening campaign enabled identification of small molecules with different chemical scaffolds that inhibit this crucial intermediate in the HIV-1 entry process. This study's observations substantiate the expediency of time-resolved FRET-based assays to identify small-molecule inhibitors of protein-protein interactions. ( Journal of Biomolecular Screening 2007:865-874)
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