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Malek-Khatabi A, Rad-Malekshahi M, Shafiei M, Sharifi F, Motasadizadeh H, Ebrahiminejad V, Rad-Malekshahi M, Akbarijavar H, Faraji Rad Z. Botulinum toxin A dissolving microneedles for hyperhidrosis treatment: design, formulation and in vivo evaluation. Biomater Sci 2023; 11:7784-7804. [PMID: 37905676 DOI: 10.1039/d3bm01301d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Multiple periodic injections of botulinum toxin A (BTX-A) are the standard treatment of hyperhidrosis which causes excessive sweating. However, BTX-A injections can create problems, including incorrect and painful injections, the risk of drug entry into the bloodstream, the need for medical expertise, and waste disposal problems. New drug delivery systems can substantially reduce these problems. Transdermal delivery is an effective alternative to conventional BTX-A injections. However, BTX-A's large molecular size and susceptibility to degradation complicate transdermal delivery. Dissolving microneedle patches (DMNPs) encapsulated with BTX-A (BTX-A/DMNPs) are a promising solution that can penetrate the dermis painlessly and provide localized translocation of BTX-A. In this study, using high-precision 3D laser lithography and subsequent molding, DMNPs were prepared based on a combination of biocompatible polyvinylpyrrolidone and hyaluronic acid polymers to deliver BTX-A with ultra-sharp needle tips of 1.5 ± 0.5 µm. Mechanical, morphological and histological assessments of the prepared DMNPs were performed to optimize their physicochemical properties. Furthermore, the BTX-A release and diffusion kinetics across the skin layers were investigated. A COMSOL simulation was conducted to study the diffusion process. The primary stability analysis reported significant stability for three months. Finally, the functionality of the BTX-A/DMNPs for the suppression of sweat glands was confirmed on the hyperhidrosis mouse footpad, which drastically reduced sweat gland activity. The results demonstrate that these engineered DMNPs can be an effective, painless, inexpensive alternative to hypodermic injections when treating hyperhidrosis.
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Affiliation(s)
- Atefeh Malek-Khatabi
- Department of Pharmaceutical Biomaterials and Medical Biomaterials Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mazda Rad-Malekshahi
- Department of Pharmaceutical Biomaterials and Medical Biomaterials Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Morvarid Shafiei
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Fatemeh Sharifi
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Hamidreza Motasadizadeh
- Department of Pharmaceutical Nanotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Vahid Ebrahiminejad
- School of Engineering, University of Southern Queensland, Springfield, Queensland, 4300, Australia.
| | | | - Hamid Akbarijavar
- Department of Pharmaceutical Biomaterials and Medical Biomaterials Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Faraji Rad
- School of Engineering, University of Southern Queensland, Springfield, Queensland, 4300, Australia.
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Lin L, Olson ME, Sugane T, Turner LD, Tararina MA, Nielsen AL, Kurbanov EK, Pellett S, Johnson EA, Cohen SM, Allen KN, Janda KD. Catch and Anchor Approach To Combat Both Toxicity and Longevity of Botulinum Toxin A. J Med Chem 2020; 63:11100-11120. [PMID: 32886509 PMCID: PMC7581224 DOI: 10.1021/acs.jmedchem.0c01006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Botulinum neurotoxins have remarkable persistence (∼weeks to months in cells), outlasting the small-molecule inhibitors designed to target them. To address this disconnect, inhibitors bearing two pharmacophores-a zinc binding group and a Cys-reactive warhead-were designed to leverage both affinity and reactivity. A series of first-generation bifunctional inhibitors was achieved through structure-based inhibitor design. Through X-ray crystallography, engagement of both the catalytic Zn2+ and Cys165 was confirmed. A second-generation series improved on affinity by incorporating known reversible inhibitor pharmacophores; the mechanism was confirmed by exhaustive dialysis, mass spectrometry, and in vitro evaluation against the C165S mutant. Finally, a third-generation inhibitor was shown to have good cellular activity and low toxicity. In addition to our findings, an alternative method of modeling time-dependent inhibition that simplifies assay setup and allows comparison of inhibition models is discussed.
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Affiliation(s)
- Lucy Lin
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Margaret E. Olson
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Takashi Sugane
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Lewis D. Turner
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Margarita A. Tararina
- Program in Biomolecular Pharmacology, Boston University School of Medicine, Boston, Massachusetts 02118, United States
| | - Alexander L. Nielsen
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Elbek K. Kurbanov
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Eric A. Johnson
- Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Seth M. Cohen
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Karen N. Allen
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Kim D. Janda
- Departments of Chemistry and Immunology, The Skaggs Institute for Chemical Biology, Worm Institute of Research and Medicine (WIRM), Scripps Research, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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Abstract
Proteases play a pivotal role in regulating important physiological processes from food digestion to blood clotting. They are also important biomarkers for many diseases such as cancers. The importance of proteases has led to extensive efforts in the screening of proteases and their inhibitors as potential drug molecules. For example, human immunodeficiency virus (HIV) patients have been treated with HIV-1 protease inhibitors to prolong the life expectancy of patients. Such a close relationship between diseases and proteases provides a strong motivation for developing sensitive, selective, and robust protease assays and sensors, which can be exploited to discover new proteases and inhibitors. In this aspect, protease assays based on levels of proteolytic activities are more relevant than protease affinity assays such as immunoassays. In this review, recent developments of protease activity assays based on different detection principles are discussed and compared. For homogenous assays, fluorescence-based techniques are the most popular due to their high sensitivity and quantitative results. However, homogeneous assays have limited multiplex sensing capabilities. In contrast, heterogeneous assays can be employed to detect multiple proteases simultaneously, given the microarray technology that is already available. Among them, electrochemical methods, surface spectroscopy techniques, and enzyme-linked peptide protease assays are commonly used. Finally, recent developments in liquid crystal (LC)-based protease assays and their applications for detecting proteases and their inhibitors are discussed.
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Affiliation(s)
| | - Kun-Lin Yang
- National University of Singapore, 4 Engineering Drive 4, Singapore 117585.
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Feltrup TM, Patel K, Kumar R, Cai S, Singh BR. A novel role of C-terminus in introducing a functionally flexible structure critical for the biological activity of botulinum neurotoxin. Sci Rep 2018; 8:8884. [PMID: 29891845 PMCID: PMC5995822 DOI: 10.1038/s41598-018-26764-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 05/17/2018] [Indexed: 02/06/2023] Open
Abstract
Botulinum neurotoxin (BoNT) is responsible for botulism, a clinical condition resulting in flaccid muscle paralysis and potentially death. The light chain is responsible for its intracellular toxicity through its endopeptidase activity. Available crystal structures of BoNT/A light chains (LCA) are based on various truncated versions (tLCA) of the full-length LCA (fLCA) and do not necessarily reflect the true structure of LCA in solution. The understanding of the mechanism of action, longevity of intoxication, and an improved development of endopeptidase inhibitors are dependent on first having a better insight into the structure of LCA in solution. Using an array of biophysical techniques, we report that the fLCA structure is significantly more flexible than tLCA in solution, which may be responsible for its dramatically higher enzymatic activity. This seems to be achieved by a much stronger, more rapid binding to substrate (SNAP-25) of the fLCA compared to tLCA. These results suggest that the C-terminus of LCA plays a critical role in introducing a flexible structure, which is essential for its biological function. This is the first report of such a massive structural role of the C-terminus of a protein being critical for maintaining a functional state.
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Affiliation(s)
- Thomas M Feltrup
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Kruti Patel
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, North Dartmouth, MA, 02747, USA
| | - Shuowei Cai
- Department of Chemistry & Biochemistry, University of Massachusetts Dartmouth, North Dartmouth, MA, 02747, USA
| | - Bal Ram Singh
- Botulinum Research Center, Institute of Advanced Sciences, North Dartmouth, MA, 02747, USA.
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Rumlová M, Ruml T. In vitro methods for testing antiviral drugs. Biotechnol Adv 2018; 36:557-576. [PMID: 29292156 PMCID: PMC7127693 DOI: 10.1016/j.biotechadv.2017.12.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/22/2017] [Accepted: 12/27/2017] [Indexed: 12/24/2022]
Abstract
Despite successful vaccination programs and effective treatments for some viral infections, humans are still losing the battle with viruses. Persisting human pandemics, emerging and re-emerging viruses, and evolution of drug-resistant strains impose continuous search for new antiviral drugs. A combination of detailed information about the molecular organization of viruses and progress in molecular biology and computer technologies has enabled rational antivirals design. Initial step in establishing efficacy of new antivirals is based on simple methods assessing inhibition of the intended target. We provide here an overview of biochemical and cell-based assays evaluating the activity of inhibitors of clinically important viruses.
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Affiliation(s)
- Michaela Rumlová
- Department of Biotechnology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague 166 28, Czech Republic.
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Ambrin G, Kumar R, Singh BR. Differential endopeptidase activity of different forms of type A botulinum neurotoxin: A unique relationship between the size of the substrate and activity of the enzyme. Toxicon 2018; 144:34-41. [PMID: 29309744 DOI: 10.1016/j.toxicon.2017.12.055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/27/2017] [Accepted: 12/30/2017] [Indexed: 10/18/2022]
Abstract
Botulinum neurotoxins (BoNTs; serotypes A-G) are metalloproteases, which cleave and inactivate cellular proteins essential for neurotransmitter release. In bacterial cultures, BoNTs are secreted as a complex of the neurotoxin and a group of neurotoxin associated proteins (NAPs). Under physiological condition (pH 7.4), this complex is believed to be dissociated to separate the neurotoxin from NAPs. BoNT consists of a 50 kDa light (L) chain (LC or catalytic domain) and a 100 kDa heavy (H) chain (or HC) linked through a disulfide bond and other non-covalent interactions. The cell intoxication involves three major steps; binding, membrane translocation and inhibition of neurotransmitter release. The last step of intoxication, endopeptidase activity, is very unique and specific that can be used for detection of the complex and isolated forms of the toxin. A fluorescent tag-labeled synthetic peptide (SNAPtide) derived from a segment of SNAP-25, an intracellular substrate of BoNT/A, is used to detect and assay the endopeptidase activity of BoNT/A. The detection of the signal is based on the change in the fluorescence energy transfer after selective cleavage of the peptide by the BoNT/A. In this report, we demonstrate that SNAPtide as a commonly used substrate widely differ in reaction with BoNT/A complex, BoNT/A, and BoNT/A light chain. These findings have implications for assays used in detection, and in screening potential inhibitors.
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Affiliation(s)
- Ghuncha Ambrin
- Department of Chemistry and Biochemistry, University of Massachusetts, North Dartmouth, MA, 02747, USA
| | - Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA
| | - Bal Ram Singh
- Department of Chemistry and Biochemistry, University of Massachusetts, North Dartmouth, MA, 02747, USA; Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
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High Yield Preparation of Functionally Active Catalytic-Translocation Domain Module of Botulinum Neurotoxin Type A That Exhibits Uniquely Different Enzyme Kinetics. Protein J 2017; 36:489-501. [PMID: 29030733 DOI: 10.1007/s10930-017-9744-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most toxic proteins known to cause flaccid muscle paralysis as a result of inhibition of neurotransmitter release from peripheral cholinergic synapses. BoNT type A (BoNT/A) is a 150 kDa protein consisting of two major subunits: light chain (LC) and heavy chain (HC). The LC is required for the catalytic activity of neurotoxin, whereas the C and N terminal domains of the HC are required for cell binding, and translocation of LC across the endosome membranes, respectively. To better understand the structural and functional aspects of BoNT/A intoxication we report here the development of high yield Escherichia coli expression system (2-20-fold higher yield than the value reported in the literature) for the production of recombinant light chain-translocation domain (rLC-TD/A) module of BoNT/A which is catalytically active and translocation competent. The open reading frame of rLC-TD/A was PCR amplified from deactivated recombinant BoNT/A gene (a non-select agent reagent), and was cloned using pET45b (+) vector to express in E. coli cells. The purification procedure included a sequential order of affinity chromatography, trypsinization, and anion exchange column chromatography. We were able to purify > 95% pure, catalytically active and structurally well-folded protein. Comparison of enzyme kinetics of purified LC-TD/A to full-length toxin and recombinant light chain A suggest that the affinity for the substrate is in between endopeptidase domain and botulinum toxin. The potential application of the purified protein has been discussed in toxicity and translocation assays.
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Liu J, Gao S, Kang L, Ji B, Xin W, Kang J, Li P, Gao J, Wang H, Wang J, Yang H. An Ultrasensitive Gold Nanoparticle-based Lateral Flow Test for the Detection of Active Botulinum Neurotoxin Type A. NANOSCALE RESEARCH LETTERS 2017; 12:227. [PMID: 28359137 PMCID: PMC5371539 DOI: 10.1186/s11671-017-1944-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 02/22/2017] [Indexed: 06/07/2023]
Abstract
Botulism is a severe and potentially lethal paralytic disease caused by several botulinum neurotoxin-producing Clostridia spp. In China, the majority of the cases caused by botulism were from less-developed rural areas. Here, we designed specific substrate peptides and reconfigured gold nanoparticle-based lateral flow test strip (LFTS) to develop an endopeptidase-based lateral flow assay for the diagnosis of botulism. We performed this lateral flow assay on botulinum neurotoxin-spiked human serum samples. The as-prepared LFTS had excellent performance in the detection of botulinum neurotoxin using only 1 μL of simulated serum, and its sensitivity and specificity were comparable to that of mouse lethality assay. Moreover, the assay takes only half a day and does not require highly trained laboratory staff, specialized facility, or equipment. Finally, our LFTS can be potentially extended to other serotypes of BoNTs by designing specific substrate peptides against the different types of BoNTs. Overall, we demonstrate a strategy by which LFTS and endopeptidase activity assays can be integrated to achieve facile and economic diagnosis of botulism in resource-limited settings.
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Affiliation(s)
- Jing Liu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
- The 307th Hospital of Military Chinese People's Liberation Army, Beijing, 100071, People's Republic of China
| | - Shan Gao
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Lin Kang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Bin Ji
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Wenwen Xin
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Jingjing Kang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Ping Li
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Jie Gao
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China
| | - Hanbin Wang
- The 307th Hospital of Military Chinese People's Liberation Army, Beijing, 100071, People's Republic of China
| | - Jinglin Wang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
| | - Hao Yang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, People's Republic of China.
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9
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Minnow YV, Goldberg R, Tummalapalli SR, Rotella DP, Goodey NM. Mechanism of inhibition of botulinum neurotoxin type A light chain by two quinolinol compounds. Arch Biochem Biophys 2017; 618:15-22. [DOI: 10.1016/j.abb.2017.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/06/2017] [Accepted: 01/12/2017] [Indexed: 11/26/2022]
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11
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Guo J, Xu C, Li X, Chen S. A simple, rapid and sensitive FRET assay for botulinum neurotoxin serotype B detection. PLoS One 2014; 9:e114124. [PMID: 25437190 PMCID: PMC4250190 DOI: 10.1371/journal.pone.0114124] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 11/04/2014] [Indexed: 12/20/2022] Open
Abstract
Botulinum neurotoxins (BoNTs), the most potent naturally-occurring neurotoxins known to humans, comprise seven distinct serotypes (BoNT/A-G), each of which exhibits unique substrate specificity. Many methods have been developed for BoNT detection, in particular for BoNT/A, with various complexity and sensitivity, while substrate based FRET assay is considered as the most widely used approach due to its simplicity and sensitivity. In this study, we designed a vesicle-associated membrane protein 2 (VAMP2) based FRET assay based on the understanding of the VAMP2 and light chain/B (LC/B) interactions in our previous studies. The current design constituted the shortest peptide, VAMP2 (63–85), with FRET dyes (EDAN and Dabcyl) labelled at position 76 and 85, respectively, which showed minimal effect on VAMP2 substrate catalysis by LC/B and therefore enhanced the sensitivity of the assay. The FRET peptide, designated as FVP-B, was specific to LC/B, with a detection sensitivity as low as ∼20 pM in 2 h. Importantly, FVP-B showed the potential to be scaled up and used in high throughput screening of LC/B inhibitor. The currently developed FRET assay is one of the most economic and rapid FRET assays for LC/B detection.
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Affiliation(s)
- Jiubiao Guo
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
| | - Ci Xu
- Department of Chemistry, University of Hong Kong, Pokfulam, Hong Kong
| | - Xuechen Li
- Department of Chemistry, University of Hong Kong, Pokfulam, Hong Kong
- * E-mail: (XL); (SC)
| | - Sheng Chen
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR
- * E-mail: (XL); (SC)
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12
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Shi J, Guo J, Bai G, Chan C, Liu X, Ye W, Hao J, Chen S, Yang M. A graphene oxide based fluorescence resonance energy transfer (FRET) biosensor for ultrasensitive detection of botulinum neurotoxin A (BoNT/A) enzymatic activity. Biosens Bioelectron 2014; 65:238-44. [PMID: 25461164 DOI: 10.1016/j.bios.2014.10.050] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 11/18/2022]
Abstract
Botulinum neurotoxins (BoNTs) are among the most potent toxic bacterial proteins for humans, which make them potential agents for bioterrorism. Therefore, an ultrasensitive detection of BoNTs and their active states is in great need as field-deployable systems for anti-terrorism applications. We report the construction of a novel graphene oxide (GO)-peptide based fluorescence resonance energy transfer (FRET) biosensor for ultrasensitive detection of the BoNT serotype A light chain (BoNT-LcA) protease activity. A green fluorescence protein (GFP) modified SNAP-25 peptide substrate (SNAP-25-GFP) was optimally designed and synthesized with the centralized recognition/cleavage sites. This FRET platform was constructed by covalent immobilization of peptide substrate on GO with BSA passivation which have advantages of low non-specific adsorption and high stability in protein abundant solution. BoNT-LcA can specifically cleave SNAP-25-GFP substrate covalently immobilized on GO to release the fragment with GFP. Based on fluorescence signal recovery measurement, the target BoNT-LcA was detected sensitively and selectively with the linear detection range from 1fg/mL to 1pg/mL. The limit of detection (LOD) for BoNT-LcA is around 1fg/mL.
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Affiliation(s)
- Jingyu Shi
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China
| | - Jiubiao Guo
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Gongxun Bai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Chunyu Chan
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China
| | - Xuan Liu
- Institute of Textiles & Clothing, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Weiwei Ye
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China
| | - Jianhua Hao
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Sheng Chen
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, PR China
| | - Mo Yang
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China.
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