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Murakami H, Fujikawa Y, Mori M, Mosu N, Taguchi A, Hayashi Y, Inoue H, Kamisuki S. Development of a novel fluorogenic assay method for screening inhibitors of bovine leukemia virus protease and identification of mitorubrinic acid as an anti-BLV compound. Biosci Biotechnol Biochem 2023; 87:946-953. [PMID: 37280167 DOI: 10.1093/bbb/zbad073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/31/2023] [Indexed: 06/08/2023]
Abstract
Bovine leukemia virus (BLV) causes enzootic bovine leukosis, a fatal cattle disease that leads to significant economic losses in the livestock industry. Currently, no effective BLV countermeasures exist, except testing and culling. In this study, we developed a high-throughput fluorogenic assay to evaluate the inhibitory activity of various compounds on BLV protease, an essential enzyme for viral replication. The developed assay method was used to screen a chemical library, and mitorubrinic acid was identified as a BLV protease inhibitor that exhibited stronger inhibitory activity than amprenavir. Additionally, the anti-BLV activity of both compounds was evaluated using a cell-based assay, and mitorubrinic acid was found to exhibit inhibitory activity without cytotoxicity. This study presents the first report of a natural inhibitor of BLV protease-mitorubrinic acid-a potential candidate for the development of anti-BLV drugs. The developed method can be used for high-throughput screening of large-scale chemical libraries.
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Affiliation(s)
- Hironobu Murakami
- School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
- Center for Human and Animal Symbiosis Science, Azabu University, Sagamihara, Kanagawa, Japan
| | - Yuuta Fujikawa
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Masaya Mori
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Nozomi Mosu
- School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
| | - Akihiro Taguchi
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Yoshio Hayashi
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Hideshi Inoue
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| | - Shinji Kamisuki
- School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
- Center for Human and Animal Symbiosis Science, Azabu University, Sagamihara, Kanagawa, Japan
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Chen Y, Liu Y, Yao Y, Zhang S, Gu Z. Reverse micelle-based water-soluble nanoparticles for simultaneous bioimaging and drug delivery. Org Biomol Chem 2018; 15:3232-3238. [PMID: 28327735 DOI: 10.1039/c7ob00169j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
With special confined water pools, reverse micelles (RMs) have shown potential for a wide range of applications. However, the inherent water-insolubility of RMs hinders their further application prospects, especially for applications related to biology. We recently reported the first successful transfer of RMs from organic media to an aqueous phase without changing the smart water pools by the hydrolysis of an arm-cleavable interfacial cross-linked reverse micelles. Herein, we employed another elaborate amphiphile 1 to construct new acrylamide-based cross-linked water-soluble nanoparticles (ACW-NPs) under much gentler conditions. The special property of the water pools of the ACW-NPs was confirmed by both the Förster resonance energy transfer (FRET) between 5-((2-aminoethyl)amino)naphthalene-1-sulfonic acid (1,5-EDANS) and benzoic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl] (DABCYL) and satisfactory colloidal stability in 10% fetal bovine serum. Importantly, featured by the gentle synthetic strategy, confined water pool, and carboxylic acid-functionalized surface, the new ACW-NPs are well suitable for biological applications. As an example, the fluorescent reagent 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) was encapsulated in the core and simultaneously, the anticancer drug gemcitabine (Gem) was covalently conjugated onto the surface exterior. As expected, the resulting multifunctional ACW-NPs@HPTS@Gem exhibits a high imaging effect and anticancer activity for non-small lung cancer cells.
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Affiliation(s)
- Ying Chen
- National Engineering Research Centre for Biomaterials, Sichuan University, 29 Wangjiang Road, Chengdu 610064, China.
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Wei T, Furgal JC, Jung JH, Scott TF. Long, self-assembled molecular ladders by cooperative dynamic covalent reactions. Polym Chem 2017. [DOI: 10.1039/c6py01951j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The dynamic covalent self-assembly of peptoid-based oligomers bearing n complementary functional groups yields molecular ladders with n covalent rungs.
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Affiliation(s)
- Tao Wei
- Department of Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
| | - Joseph C. Furgal
- Department of Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
| | - Jae Hwan Jung
- Macromolecular Science and Engineering
- University of Michigan
- Ann Arbor
- USA
| | - Timothy F. Scott
- Department of Chemical Engineering
- University of Michigan
- Ann Arbor
- USA
- Macromolecular Science and Engineering
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Handa B, Keech E, Conway E, Broadhurst A, Ritchie A. Design and Synthesis of a Quenched Fluorogenic Peptide Substrate for Human Cytomegalovirus Proteinase. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029500600408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A fluorogenic peptide substrate for HCMV proteinase was synthesized by solid-phase peptide synthesis. The amino acid sequence of this substrate is derived from the maturation cleavage site (M site) of the natural substrate, the assembly protein precursor. The minimum sequence for efficient cleavage requires at least seven residues (P4-P3′). A systematic modification of the peptide substrate was carried out to identify positions suitable for the introduction of the fluorescent donor and the quencher acceptor groups.
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Affiliation(s)
- B.K. Handa
- Department of Physical Methods, Roche Products Limited, PO Box 8, Welwyn Garden City, Hertfordshire AL7 3AY, UK
| | - E. Keech
- Department of Physical Methods, Roche Products Limited, PO Box 8, Welwyn Garden City, Hertfordshire AL7 3AY, UK
| | - E.A. Conway
- Department of Physical Methods, Roche Products Limited, PO Box 8, Welwyn Garden City, Hertfordshire AL7 3AY, UK
| | - A. Broadhurst
- Department of Biology, Roche Products Limited, PO Box 8, Welwyn Garden City, Hertfordshire AL7 3AY, UK
| | - A. Ritchie
- Department of Biology, Roche Products Limited, PO Box 8, Welwyn Garden City, Hertfordshire AL7 3AY, UK
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Andersen RJ, Brask J. Synthesis and evaluation of fluorogenic triglycerides as lipase assay substrates. Chem Phys Lipids 2016; 198:72-9. [DOI: 10.1016/j.chemphyslip.2016.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 05/23/2016] [Accepted: 05/25/2016] [Indexed: 10/21/2022]
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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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Cheng YM, Wu IC, Lai CH, Pu SC, Chou PT, Wei CY, Yu CY, Lin YH, Ting C. Femtosecond Spectroscopy and Dynamics of the Azulenylosquaric Dye, a Near-infrared Nonfluorogenic Quencher. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200600170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Law B, Tung CH. Proteolysis: A Biological Process Adapted in Drug Delivery, Therapy, and Imaging. Bioconjug Chem 2009; 20:1683-95. [DOI: 10.1021/bc800500a] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Benedict Law
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58105, and The Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, Texas 77030
| | - Ching-Hsuan Tung
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58105, and The Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, Texas 77030
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Elston C, Wallach J, Saulnier J. New continuous and specific fluorometric assays for Pseudomonas aeruginosa elastase and LasA protease. Anal Biochem 2007; 368:87-94. [PMID: 17553454 DOI: 10.1016/j.ab.2007.04.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 04/23/2007] [Accepted: 04/23/2007] [Indexed: 11/19/2022]
Abstract
A highly sensitive assay based on new internally quenched fluorogenic peptide substrates has been developed for monitoring protease activities. These novel substrates comprise an Edans (5-(2-aminoethylamino)-1-naphthalenesulfonic acid) group at the C terminus and a Dabsyl (4-(dimethylamino)azobenzene-4'-sulfonyl chloride) fluorophore at the N terminus of the peptide chains. The Edans fluorescence increases upon peptide hydrolysis by Pseudomonas aeruginosa proteases, and this increase is directly proportional to the amount of substrate cleaved, i.e., protease activity. The substrates Dabsyl-Ala-Ala-Phe-Ala-Edans and Dabsyl-Leu-Gly-Gly-Gly-Ala-Edans were used for testing the peptidasic activities of P. aeruginosa elastase and LasA protease, respectively. Elastase and LasA kinetic parameters were calculated and a sensitive assay was designed for the detection of P. aeruginosa proteases in bacterial supernatants. The sensitivity and the small sample requirements make the assay suitable for high-throughput screening of biological samples. Furthermore, this P. aeruginosa protease assay improves upon existing assays because it is simple, it requires only one step, and even more significantly it is enzyme specific.
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Affiliation(s)
- Caroline Elston
- Laboratoire de Biochimie Analytique & Synthèse Bioorganique, UFR Chimie-Biochimie, Université Claude Bernard Lyon 1, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
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Hennig A, Florea M, Roth D, Enderle T, Nau WM. Design of peptide substrates for nanosecond time-resolved fluorescence assays of proteases: 2,3-Diazabicyclo[2.2.2]oct-2-ene as a noninvasive fluorophore. Anal Biochem 2007; 360:255-65. [PMID: 17134673 DOI: 10.1016/j.ab.2006.09.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 09/15/2006] [Accepted: 09/17/2006] [Indexed: 11/26/2022]
Abstract
Fluorescence protease assays were investigated with peptide substrates containing a 2,3-diazabicyclo[2.2.2]oct-2-ene-labeled asparagine (Dbo) as a fluorescent amino acid. The special characteristic of the fluorophore Dbo is its exceedingly long fluorescence lifetime (ca. 300 ns in water under air), which allows the use of nanosecond time-resolved fluorescence (Nano-TRF) detection to efficiently suppress shorter-lived background emission. In addition, the natural amino acids tryptophan and tyrosine can be employed as intramolecular fluorescence quenchers, which facilitates substrate design. Fourteen synthetic peptide substrates (composed of 2-19 amino acids) and five enzymes (trypsin, pepsin, carboxypeptidase A, leucine aminopeptidase, and chymotrypsin) were investigated and, in all 28 examined combinations, enzymatic activity was detected by monitoring the increase in steady state fluorescence with time and determining the reaction rates as kcat/Km values, which ranged from 0.2 to 80x10(6) M-1 min-1. The results suggest an excellent compatibility of the very small and hydrophilic fluorescent probe Dbo with solid-phase peptide synthesis and the investigated proteases. For all 14 peptides the fluorescence lifetimes before and after enzymatic cleavage were measured and Nano-TRF measurements were performed in 384-well microplates. The fluorescence lifetimes of the different peptides provide the basis for the rational design of Dbo-based fluorescent substrates for protease assays. Measurements in Nano-TRF mode revealed, in addition to efficient suppression of background fluorescence, an increased differentiation between cleaved and uncleaved substrate. The Dbo-based assays can be adapted for high-throughput screening.
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Affiliation(s)
- Andreas Hennig
- School of Engineering and Science, International University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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11
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Horáková D, Rumlová M, Pichová I, Ruml T. Luminometric method for screening retroviral protease inhibitors. Anal Biochem 2005; 345:96-101. [PMID: 16125122 DOI: 10.1016/j.ab.2005.07.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 06/30/2005] [Accepted: 07/12/2005] [Indexed: 01/08/2023]
Abstract
We have developed a sensitive luminometric assay for determining the activity of retroviral proteases that uses proteolytic cleavage of polypeptide substrate immobilized on Ni-NTA HisSorb Strips microplates. The protease substrate derived from the Gag precursor protein of Mason-Pfizer monkey virus (M-PMV) was conjugated with horseradish peroxidase (HRP), which catalyzes oxidation of luminol in the assay. The cleavage of the substrate was monitored as a decrease in luminescent signal caused by the release of the cleavage product conjugated to HRP. Testing of a set of M-PMV protease inhibitors confirmed that this method is sufficiently sensitive and specific for high-throughput screening of retroviral protease inhibitors.
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Affiliation(s)
- Dana Horáková
- Department of Biochemistry and Microbiology, Institute of Chemical Technology, Technická 3, 166 28 Prague, Czech Republic
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12
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Abstract
Recently, many novel peptide-based near-infrared (NIR) fluorescent molecular probes have been developed for in vivo biomedical imaging. To report specific information of biological targets, the probes were individually designed according to the unique property or functions of their targets. These peptide-based probes can be classified into targeting, crosslinking, and enzyme-activatable probes. Several of them have been tested in various in vitro and in vivo models, and the obtained imaging information has been applied to disease detection, medical diagnosis, and drug evaluations.
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Affiliation(s)
- Ching-Hsuan Tung
- Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
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13
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A solid phase linker strategy for the direct synthesis of EDANS-labelled peptide substrates. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2004.11.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Chen S, Chen LL, Luo HB, Sun T, Chen J, Ye F, Cai JH, Shen JK, Shen X, Jiang HL. Enzymatic activity characterization of SARS coronavirus 3C-like protease by fluorescence resonance energy transfer technique. Acta Pharmacol Sin 2005; 26:99-106. [PMID: 15659121 PMCID: PMC7091904 DOI: 10.1111/j.1745-7254.2005.00010.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Aim: To characterize enzymatic activity of severe acute respiratory syndrome (SARS) coronavirus (CoV) 3C-like protease (3CLpro) and its four site-directed mutants. Methods: Based on the fluorescence resonance energy transfer (FRET) principle using 5-[(2′-aminoethyl)-amino] naphthelenesulfonic acid (EDANS) and 4-[[4-(dimethylamino) phenyl] azo] benzoic acid (Dabcyl) as the energy transfer pair, one fluorogenic substrate was designed for the evaluation of SARS-CoV 3CLpro proteolytic activity. Results: The kinetic parameters of the fluorogenic substrate have been determined as Km=404 μmol·L−1, kcat=1.08 min−1, and kcat/Km=2.7 mmol−1·L·min−1. SARS-CoV 3CLpro showed substantial pH and temperature-triggered activity switches, and site-directed mutagenesis analysis of SARS-CoV 3CLpro revealed that substitutions of His41, Cys145, and His163 resulted in complete loss of enzymatic activity, while replacement of Met162 with Ala caused strongly increased activity. Conclusion: This present work has provided valuable information for understanding the catalytic mechanism of SARS-CoV 3CLpro. This FRET-based assay might supply an ideal approach for the exploration SARS-CoV 3CLpro putative inhibitors.
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Affiliation(s)
- Shuai Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Li-li Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Hai-bin Luo
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Tao Sun
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Jing Chen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Fei Ye
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Jian-hua Cai
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Jing-kang Shen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Xu Shen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
| | - Hua-liang Jiang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai, 201203 China
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Bagossi P, Kádas J, Miklóssy G, Boross P, Weber IT, Tözsér J. Development of a microtiter plate fluorescent assay for inhibition studies on the HTLV-1 and HIV-1 proteinases. J Virol Methods 2004; 119:87-93. [PMID: 15158589 DOI: 10.1016/j.jviromet.2004.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2003] [Revised: 10/18/2003] [Accepted: 03/01/2004] [Indexed: 10/26/2022]
Abstract
The proteinase of human T-cell leukemia virus type-1 (HTLV-1), similar to the proteinase of human immunodeficiency virus type-1 (HIV-1), is a potential target for chemotherapy, since the virus is associated with a number of human diseases. A microtiter plate fluorescent assay was developed for the HTLV-1 and HIV-1 proteinases for direct comparison of the inhibition profiles of the enzymes. It was established that, except for Indinavir, none of the inhibitors designed against the HIV-1 proteinase were able to inhibit the HTLV-1 proteinase in the studied concentration range, while two reduced peptide bond-containing peptides having the sequence of HTLV-1 cleavage sites were inhibitors of the HTLV-1 proteinase. One of these was potent enough to be used for active site titration of the HTLV-1 proteinase.
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Affiliation(s)
- Péter Bagossi
- Department of Biochemistry and Molecular Biology, Research Center for Molecular Medicine, Medical and Health Science Center, University of Debrecen, H4012 POB 6 Debrecen, Hungary
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Pham W, Weissleder R, Tung CH. A practical approach for the preparation of monofunctional azulenyl squaraine dye. Tetrahedron Lett 2003; 44:3975-3978. [PMID: 20740053 DOI: 10.1016/s0040-4039(03)00819-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis of monofunctional azulenyl squaraine dye NIRQ(700) is described. The essential azulene intermediate 3, 1-(methoxycarbonyl)-2-methylazulene, was achieved via [8+2] cycloaddition between lactone 2, 2H-3-methoxycarbonyl-cyclohepta[b]furan-2-one, and the in situ generated vinyl ethers under high temperature and pressure conditions. Methylation on the cycloheptatriene ring of 2-methyl azulene 6 via Meisenheimer-type intermediate following Schrott's method formed the carboxylic acid intermediate 9, 3-(2-methyl-azulen-4-yl)-propionic acid. Condensation of 9 with squaric acid provided the title compound NIRQ(700) at moderate yields. The non-fluorescent squaraine dye NIRQ(700) absorbed in a 600-700 nm range and potentially can be used to quench a number of available NIR fluorochromes in order to extend the spectrum of biological quenching assays.
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Affiliation(s)
- Wellington Pham
- Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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Wang L, Hall JG, Lu M, Liu Q, Smith LM. A DNA computing readout operation based on structure-specific cleavage. Nat Biotechnol 2001; 19:1053-9. [PMID: 11689851 DOI: 10.1038/nbt1101-1053] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe a structure-specific cleavage-based READOUT strategy for surface-based DNA computing. The strategy was demonstrated in the solution of a 4-variable/3-satisfiability (SAT) problem. The READOUT step identifies the DNA molecules present at the end of the computational process. The specificity of the sequence detection used here derives from the sequence specificity of DNA hybridization coupled with the structure specificity of the enzymatic cleavage. The process is linear, yielding a higher uniformity of detection of the DNA computing products compared to that obtained with PCR amplification. The structure-specific cleavage-based readout is simple, accurate, and compatible with multiple-word DNA computing.
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Affiliation(s)
- L Wang
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA
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Badalassi F, Wahler D, Klein G, Crotti P, Reymond JL. A Versatile Periodate-Coupled Fluorogenic Assay for Hydrolytic Enzymes We would like to thank Prof. R. Furstoss and Dr. A. Archelas at the Faculté des Sciences de Luminy, Marseille (France) for providing a sample of Aspergillus niger EH and Dr. C. Weijers at the Department of Food Technology and Nutrition Sciences, Wageningen University (the Netherlands) for providing a sample of Rhodotorula glutinis EH. This work was supported by the University of Bern, the European COST program (Action D12), the Swiss Office Fédéral de l'Education et de la Science, the Wander Stiftung, the Ministero della Università e della Ricerca Scientifica e Tecnologica (MURST), and Consiglio Nazionale delle Ricerche (CNR) (Roma). P.C. gratefully acknowledges Merck for generous financial support from the 1999 ADP Chemistry Award. Angew Chem Int Ed Engl 2000; 39:4067-4070. [PMID: 11093207 DOI: 10.1002/1521-3773(20001117)39:22<4067::aid-anie4067>3.0.co;2-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- F Badalassi
- Dipartimento di Chimica Bioorganica e Biofarmacia Università di Pisa 56126 Pisa (Italy)
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Abstract
BACKGROUND We reported an aptamer, RNATat that binds to the Tat protein of HIV with two orders of magnitude greater (133-fold) affinity over the TAR RNA of HIV-1 and specifically inhibits the Tat-dependent trans-activation of transcription, both in vitro and in vivo (demonstrated in the accompanying article, Yamamoto et al., this issue pp. 371-388). We now report the use of aptamer-derived oligomers to analyze the Tat of HIV and the possible applications of such constructs in the field of biosensors. RESULTS To make new molecular beacon, we constructed two RNA oligomers that derived from RNATat. To one of the split RNA oligomers that forms a hairpin structure, the fluorophore and quencher were attached at the 5'- and 3'-ends, respectively. Specifically in the presence of Tat or its peptides, but not in the presence of other RNA binding proteins, the two oligomers undergo a conformational change to form a duplex that leads to relieving of fluorophore from the quencher, and thus a significant enhancement of the fluorescence of fluorescein was observed. CONCLUSION A novel strategy for exploiting aptamers in the analysis of Tat (analyte) has been described. A similar strategy could be used to study other analytes such as proteins and small molecules. In addition, the molecular beacon aptamer requires half the length of target sequence (eight nucleotides) in comparison with molecular beacons. Thus, it is conceivable that we could insert an analyte-binding site into molecular beacons to convert them to signalling beacons.
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Affiliation(s)
- R Yamamoto
- National Institute of Bioscience and Human Technology, University of Tsukuba, Tsukuba 305-8572, Japan
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23
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Lin YC, Beck Z, Lee T, Le VD, Morris GM, Olson AJ, Wong CH, Elder JH. Alteration of substrate and inhibitor specificity of feline immunodeficiency virus protease. J Virol 2000; 74:4710-20. [PMID: 10775609 PMCID: PMC111993 DOI: 10.1128/jvi.74.10.4710-4720.2000] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Feline immunodeficiency virus (FIV) protease is structurally very similar to human immunodeficiency virus (HIV) protease but exhibits distinct substrate and inhibitor specificities. We performed mutagenesis of subsite residues of FIV protease in order to define interactions that dictate this specificity. The I37V, N55M, M56I, V59I, and Q99V mutants yielded full activity. The I37V, N55M, V59I, and Q99V mutants showed a significant increase in activity against the HIV-1 reverse transcriptase/integrase and P2/nucleocapsid junction peptides compared with wild-type (wt) FIV protease. The I37V, V59I, and Q99V mutants also showed an increase in activity against two rapidly cleaved peptides selected by cleavage of a phage display library with HIV-1 protease. Mutations at Q54K, I98P, and L101I dramatically reduced activity. Mutants containing a I35D or I57G substitution showed no activity against either FIV or HIV substrates. FIV proteases all failed to cut HIV-1 matrix/capsid, P1/P6, P6/protease, and protease/reverse transcriptase junctions, indicating that none of the substitutions were sufficient to change the specificity completely. The I37V, N55M, M56I, V59I, and Q99V mutants, compared with wt FIV protease, all showed inhibitor specificity more similar to that of HIV-1 protease. The data also suggest that FIV protease prefers a hydrophobic P2/P2' residue like Val over Asn or Glu, which are utilized by HIV-1 protease, and that S2/S2' might play a critical role in distinguishing FIV and HIV-1 protease by specificity. The findings extend our observations regarding the interactions involved in substrate binding and aid in the development of broad-based inhibitors.
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Affiliation(s)
- Y C Lin
- Departments of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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24
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Ton-That H, Liu G, Mazmanian SK, Faull KF, Schneewind O. Purification and characterization of sortase, the transpeptidase that cleaves surface proteins of Staphylococcus aureus at the LPXTG motif. Proc Natl Acad Sci U S A 1999; 96:12424-9. [PMID: 10535938 PMCID: PMC22937 DOI: 10.1073/pnas.96.22.12424] [Citation(s) in RCA: 448] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Surface proteins of Staphylococcus aureus are linked to the bacterial cell wall by sortase, an enzyme that cleaves polypeptides at the threonine of the LPXTG motif. Surface proteins can be released from staphylococci by treatment with hydroxylamine, resulting in the formation of threonine hydroxamate. Staphylococcal extracts, as well as purified sortase, catalyze the hydroxylaminolysis of peptides bearing an LPXTG motif, a reaction that can be inhibited with sulfhydryl-modifying reagents. Replacement of the single conserved cysteine at position 184 of sortase with alanine abolishes enzyme activity. Thus, sortase appears to catalyze surface-protein anchoring by means of a transpeptidation reaction that captures cleaved polypeptides as thioester enzyme intermediates.
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Affiliation(s)
- H Ton-That
- Department of Microbiology, Department of Psychiatry, University of California, Los Angeles School of Medicine, USA
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25
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Abstract
Both isotopic and nonisotopic assay methodologies are employed in high-throughput screening for drug discovery. Recent advances in cell-based and in vitro biochemical assays will be reviewed, with special emphasis on detection technologies amenable to automated 'mix and read' procedures in high-throughput screening. A major trend is the advent of homogenous assay systems which employ fluorescence resonance energy transfer, fluorescence polarization, and fluorescence correlation spectroscopy. Cell-based assay systems have also become popular in high-throughput screens in which active compounds that directly modulate the disease target are identified. Colorimetric and amperometric methods have also been described recently, but are yet to be adapted widely in high-throughput screens.
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Affiliation(s)
- G S Sittampalam
- Research Technologies and Proteins, Lilly Research Laboratories, Eli Lilly and Company Indianapolis, Indiana, 46285, USA.
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26
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Packard BZ, Toptygin DD, Komoriya A, Brand L. Characterization of fluorescence quenching in bifluorophoric protease substrates. Biophys Chem 1997; 67:167-76. [PMID: 17029895 DOI: 10.1016/s0301-4622(97)00036-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/1997] [Revised: 03/13/1997] [Accepted: 03/14/1997] [Indexed: 11/28/2022]
Abstract
NorFES is a relatively rigid, bent undecapeptide which contains an amino acid sequence that is recognized by the serine protease elastase (AspAlaIleProNle downward arrow SerIleProLysGlyTyr ( downward arrow indicates the primary cleavage site)). Covalent attachment of a fluorophore on each side of NorFES's elastase cleavage site enables one to use a change of fluorescence intensity as a measure of enzymatic activity. In this study two bichromophoric NorFES derivatives, D-NorFES-A and D-NorFES-D, were prepared in which D (donor) was tetramethylrhodamine and A (acceptor) was rhodamine-X, two chromophores with characteristics suitable for energy transfer. Absorption and fluorescence spectra were obtained with both the intact and cleaved homodoubly, heterodoubly and singly labeled derivatives. It was found that both the homo and hetero doubly-labeled derivatives form ground-state complexes which exhibit exciton bands. The hetero labeled derivative exhibits little or no resonance energy transfer. Spectral measurements were also done in urea, which partially disrupts ground-state dimers.
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Affiliation(s)
- B Z Packard
- Oncolmmunin, Inc., 335 Paint Branch Drive, College Park, MD 20742, USA.
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27
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Vance JE, LeBlanc DA, Wingfield P, London RE. Conformational selectivity of HIV-1 protease cleavage of X-Pro peptide bonds and its implications. J Biol Chem 1997; 272:15603-6. [PMID: 9188447 DOI: 10.1074/jbc.272.25.15603] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Kinetic measurements on a fluorescent peptide analog of the p17/p24 cleavage site of the Gag polyprotein demonstrate the conformational selectivity of human immunodeficiency virus, type 1 protease for the trans conformation of the Tyr-Pro bond. A mean cis/trans ratio of 0. 3, and a cis --> trans isomerization rate constant of 0.022 s-1 are determined at T = 22 degrees C. This rate is in excellent agreement with that predicted by 19F NMR studies of structurally analogous peptides containing a fluorine/hydroxyl substitution on the tyrosyl residue. Addition of recombinant human cyclophilin resulted in a significant enhancement of this rate, and it is proposed that this enzyme, which has been shown to be associated with the Gag protein, functions as an auxiliary enzyme for the protease during cleavage in the virion.
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Affiliation(s)
- J E Vance
- Laboratory of Structural Biology, NIEHS, Research Triangle Park, North Carolina 27709, USA
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28
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Nazarenko IA, Bhatnagar SK, Hohman RJ. A closed tube format for amplification and detection of DNA based on energy transfer. Nucleic Acids Res 1997; 25:2516-21. [PMID: 9171107 PMCID: PMC146748 DOI: 10.1093/nar/25.12.2516] [Citation(s) in RCA: 232] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A new method for the direct detection of PCR-amplified DNA in a closed system is described. The method is based on the incorporation of energy transfer-labeled primers into the amplification product. The PCR primers contain hairpin structures on their 5'ends with donor and acceptor moieties located in close proximity on the hairpin stem. The primers are designed in such a way that a fluorescent signal is generated only when the primers are incorporated into an amplification product. A signal to background ratio of 35:1 was obtained using the hairpin primers labeled with fluorescein as a donor and 4-(4'-dimethylaminophenylazo) benzoic acid (DABCYL) as a quencher. The modified hairpin-primers do not interfere with the activity of DNA polymerase, and both thermostable Pfu and Taq polymerase can be used. This method was applied to the detection of cDNA for prostate specific antigen. The results demonstrate that the fluorescent intensity of the amplified product correlates with the amount of incorporated primers, and as few as 10 molecules of the initial template can be detected. This technology eliminates the risk of carry-over contamination, simplifies the amplification assay and opens up new possibilities for the real-time quantification of the amplified DNA over an extremely wide dynamic range.
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Affiliation(s)
- I A Nazarenko
- Oncor, Inc., 209 Perry Parkway, Gaithersburg, MD 20877, USA.
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29
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Abstract
Fluorescence resonance energy transfer has facilitated the development of a new class of high-performance fluorescent labeling reagents for multiplex analyses of nucleic acids. The enhanced emission of energy transfer (ET) primers has provided a decadic improvement in the performance of automated DNA sequencers. The emission spectral purity of ET primers permits the development of robust multiplex diagnostic methods for the detection of PCR products. High affinity bifunctional intercalation reagents containing ET-coupled dyes are also being used for high-performance multiplex assays of double-stranded DNA when noncovalent labeling is preferred.
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Affiliation(s)
- A N Glazer
- Department of Molecular and Cell Biology, 229 Stanley Hall, University of California, Berkeley, CA 94720-3206, USA.
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30
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Packard BZ, Toptygin DD, Komoriya A, Brand L. Design of profluorescent protease substrates guided by exciton theory. Methods Enzymol 1997; 278:15-23. [PMID: 9170307 DOI: 10.1016/s0076-6879(97)78004-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- B Z Packard
- Oncolmmunin, Inc., College Park, Maryland 20742, USA
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31
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Gershkovich AA, Kholodovych VV. Fluorogenic substrates for proteases based on intramolecular fluorescence energy transfer (IFETS). JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 1996; 33:135-62. [PMID: 9029259 DOI: 10.1016/s0165-022x(96)00023-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A prospective class of intramolecular fluorescence energy transfer substrates (IFETS) is described. In contrast to the known chromogenic and fluorogenic substrates that are used widely in the scientific and medical research, IFETS allow to control the enzymatic cleavage at any point of the peptide chain and thus permit simultaneous studies of enzymes of different specificity. We discuss the main types of donor and acceptor, their advantages and drawbacks and the effectiveness of exited-state energy transfer between them. High sensitivity and selectivity of IFETS in the assay of proteinases was demonstrated. They prove to be a very useful and very promising instrument for enzymology and medicine.
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Affiliation(s)
- A A Gershkovich
- Department of Protein Chemistry, Ukrainian National Academy of Sciences, Kiev, Ukraine.
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32
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Luker KE, Francis SE, Gluzman IY, Goldberg DE. Kinetic analysis of plasmepsins I and II aspartic proteases of the Plasmodium falciparum digestive vacuole. Mol Biochem Parasitol 1996; 79:71-8. [PMID: 8844673 DOI: 10.1016/0166-6851(96)02651-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Plasmepsins I and II are Plasmodium falciparum aspartic proteases implicated in hemoglobin degradation. Using a synthetic fluorogenic peptide substrate based on the initial hemoglobin cleavage site, we have analyzed kinetic parameters of the two enzymes in native and recombinant forms. Both native plasmepsins cleave the model substrate well. Recombinant plasmepsin II behaves similarly to native enzyme, substantiating its usefulness for inhibition and structural studies. In contrast, recombinant plasmepsin I does not resemble its native homolog kinetically. A hybrid molecule, in which the polyproline loop of plasmepsin I has been replaced by the homologous sequence from plasmepsin II, still maintains the specificity/kinetics of plasmepsin II. This suggests that the polyproline loop, important for substrate recognition in the mammalian aspartic protease renin, does not play a similar role in the plasmepsins.
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Affiliation(s)
- K E Luker
- Howard Hughes Medical Institute, Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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33
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Abstract
We have developed novel nucleic acid probes that recognize and report the presence of specific nucleic acids in homogeneous solutions. These probes undergo a spontaneous fluorogenic conformational change when they hybridize to their targets. Only perfectly complementary targets elicit this response, as hybridization does not occur when the target contains a mismatched nucleotide or a deletion. The probes are particularly suited for monitoring the synthesis of specific nucleic acids in real time. When used in nucleic acid amplification assays, gene detection is homogeneous and sensitive, and can be carried out in a sealed tube. When introduced into living cells, these probes should enable the origin, movement, and fate of specific mRNAs to be traced.
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Affiliation(s)
- S Tyagi
- Department of Molecular Genetics, Public Health Research Institute, New York, NY 10016, USA.
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34
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Garc�a-Echeverr�a C, Rich DH. Kinetic studies of papain: Effect of P3? substituents and donor/acceptor pairs of intramolecularly quenched fluorogenic substrates. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf00128501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Affiliation(s)
- C G Knight
- Department of Cell Adhesion and Signalling, Strangeways Research Laboratory, Cambridge, United Kingdom
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36
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Rice WG, Bader JP. Discovery and in vitro development of AIDS antiviral drugs as biopharmaceuticals. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1995; 33:389-438. [PMID: 7495676 DOI: 10.1016/s1054-3589(08)60675-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The goal of developing an effective drug against HIV-1 and AIDS has been approached by several routes, with enough encouraging results to stimulate further efforts. Compounds active against HIV-1 have been discovered for many of the functions in the reproductive cycle recognized as virus-specific targets. Discoveries have been made in cell-based assays as well as mechanistic assays, and the value of both types of assays in the drug discovery process has been discussed. Although the final test of a drug's efficacy comes in the clinical experience, submission of an antiviral compound to an in vitro developmental gauntlet can save much time, effort, expense, and human resource in the in vivo developmental regimen required prior to human use. Emergence of viral resistance to drugs in several structural classes has compromised their clinical efficacy, suggesting that development of other potential drugs in those classes may not be good investments. Strains of HIV-1 resistant to specific compound classes are used to categorize new active discoveries for possible developmental exclusion, and defining the mechanism of action of such a new compound may confirm the discouraging judgement. On the other hand, novel compounds which exhibit a broad range of activity in drug-resistant and other HIV-1 strains deserve greater scrutiny. Clinicians most likely will be hesitant to treat patients with compounds shown to act on virus-cell surface interactions, given the failure in the past of several such compounds in clinical studies. But a compound shown to have a unique and novel mechanism of action will be looked upon more favorably, and surviving other tests of potency, solubility, and stability will be unhesitatingly presented for in vivo development. The partial successes of drugs currently in clinical use against AIDS offers great encouragement that other more-effective, less-toxic drugs will be found. Exquisite techniques for identifying new targets on virus gene products, the selection of compounds on activity paradigms, and the enormous variety of compounds becoming available through synthesis libraries, all offer opportunities for anti-HIV drug discovery, which, in our view, cannot fail to present potent antiviral compounds which will survive the rigorous preclinical and clinical tests leading to a drug effective against AIDS.
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Affiliation(s)
- W G Rice
- Laboratory of Antiviral Drug Mechanisms, National Cancer Institute, Frederick Cancer Research and Development Center, Maryland 21701-1201, USA
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37
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Pennington MW, Baur P. A facile method to prepare C-terminal fluorescently labelled peptides by an Fmoc strategy. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf00128532] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Wang GT, Ladror US, Holzman TF, Klein WL, Krafft GA. Cleavage of fluorogenic substrates for APP-processing proteases by human brain extracts. Ca(2+)-substrate interaction is responsible for Ca2+ stimulation of the neural protease activity. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1994; 23:191-9. [PMID: 7702708 DOI: 10.1007/bf02815411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The proteases that cleave amyloid precursor protein (APP) leading to generation of amyloid A beta peptide are potential targets for therapeutical intervention of Alzheimer disease. We have been pursuing the identification and characterization of these proteases using as probes the fluorogenic substrates encompassing the cleavage sites of APP that we described recently (Wang, G. T., Krafft, G. A. [1992] Bioorg. Med. Chem. Lett. 2, 1665). This article describes results of experiments designed to examine the effect of Ca(2+) on the cleavage of these substrates by human brain extracts. Fluorogenic substrates encompassing either the N-terminal amyloidogenic cleavage site or the secretory cleavage site were synthesized in five formats with various peripheral residues. Incubation with extracts from normal brain tissue revealed that more negatively charged amyloidogenic substrates were less reactive and exhibited larger rate enhancement in the presence of Ca(2+). The results imply that Ca(2+) stimulation of substrate cleavage by brain proteases occurs primarily as a result of Ca(2+)-substrate interactions, and caution against interpretations that invoke the involvement of Ca(2+)-stimulated proteases in A beta formation.
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Affiliation(s)
- G T Wang
- Drug Design and Delivery, Pharmaceutical Product Division, Abbott Laboratories, Abbott Park, IL 60064
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39
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Ferro V, Meldal M, Bock K. Synthesis of 2′- and 2″-O-acylated maltotriosides as potential fluorescence-quenched substrates for α-amylase. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/p19940002169] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Abstract
This chapter has described a number of approaches for continuous assay of retroviral proteases using either chromogenic or fluorogenic synthetic substrates. The significant progress in this area has been catalyzed by the intense interest in HIV protease as a therapeutic target, but these versatile methods will be used widely in future for studies of many other proteases.
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Affiliation(s)
- G A Krafft
- Department of Structural Biology, Drug Design and Delivery, Abbott Laboratories, Abbott Park, Illinois 60064
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41
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Abstract
A variety of assay methods for retroviral proteases have been developed in response to different experimental requirements, such as initial identification of a protease, subsequent enzymatic characterization, and high-capacity automated screening of potential inhibitors. This chapter has reviewed a number of these methods above; most have been closely tailored to match specific experimental requirements, and some of them are described in greater detail in other chapters in this volume. They include analysis of polyprotein cleavage using SDS-PAGE, analysis of the determinants of substrate cleavage using either chromogenic peptides or reversed-phase HPLC for product separation after cleavage of unmodified peptides, and the design and utilization of quenched fluoregenic peptides for use in continuous assay.
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Affiliation(s)
- C U Hellen
- Department of Microbiology, State University of New York at Stonybrook 11794
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42
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Bolin DR. Vasoactive intestinal peptide: role of calmodulin and catalytic antibodies. Neurochem Int 1993; 23:221-7. [PMID: 8220168 DOI: 10.1016/0197-0186(93)90113-j] [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: 01/29/2023]
Abstract
In the accompanying article Paul and Ebadi [1993 (Neurochem Int. 23, 197-214)] review recent observations that the neuropeptide vasoactive intestinal peptide (VIP) and the related peptide growth hormone releasing factor (GRF) bind to two novel protein molecules unrelated to their G-protein coupled receptors. VIP and GRF have been reported to bind with high affinity to calmodulin, leading to modulation of biological activities of the regulatory protein. VIP has also been reported to bind to autoantibodies isolated from both normal and asthmatic subjects. Several of these autoantibodies have been found to catalyze the hydrolysis of the native VIP molecule. The biological consequences of the binding of VIP and GRF to these macromolecular "receptors" are considered.
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Affiliation(s)
- D R Bolin
- Roche Research Center, Hoffmann-La Roche, Inc., Nutley, NJ 07110
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43
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Wang GT, Krafft GA. Automated synthesis of fluorogenic protease substrates: design of probes for alzheimer's disease-associated proteases. Bioorg Med Chem Lett 1992. [DOI: 10.1016/s0960-894x(00)80452-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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44
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García-Echeverría C, Rich DH. Effect of P2' substituents on kinetic constants for hydrolysis by cysteine proteinases. Biochem Biophys Res Commun 1992; 187:615-9. [PMID: 1530620 DOI: 10.1016/0006-291x(92)91239-m] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Intramolecularly quenched fluorogenic peptide substrates with the general sequence: DABCYL-Lys-Phe-Gly-Gly-Xxx-Ala-EDANS have been utilized to explore the effect of the hydrophobicity of amino acid side chains in the P2' position on the steady-state kinetic constants for papain catalyzed hydrolysis. The results demonstrate that subsite interactions between the enzyme and the peptide substrate modulate the enzyme specificity by slowing the release of the C-terminal product. This series of substrates can be used to characterize substrate specificity studies of other cysteine proteinases.
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45
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Capobianco JO, Lerner CG, Goldman RC. Application of a fluorogenic substrate in the assay of proteolytic activity and in the discovery of a potent inhibitor of Candida albicans aspartic proteinase. Anal Biochem 1992; 204:96-102. [PMID: 1514700 DOI: 10.1016/0003-2697(92)90145-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A fluorescent method for monitoring the activity of the secreted Candida carboxyl (aspartic) proteinase (EC 3.4.23.6) was developed using a fluorogenic substrate based on resonance energy transfer. The fluorescent assay was used to monitor proteinase production, purification, and inhibition. The Km for the fluorogenic substrate, 4-(4-dimethylaminophenylazo)benzoyl-gamma-aminobutyryl-Ile-His-Pro - Phe-His-Leu-Val-Ile-His-Thr- [5-(2-aminoethyl)amino]naphthalene-1-sulfonic acid, was found to be 4.3 microM at the optimum pH of 4.5. Reaction products were separated by reverse-phase high-performance liquid chromatography and identified by amino acid analysis or by 252Cf plasma desorption mass spectrometry. Cleavage of the fluorogenic substrate was between the histidine-threonine residues, releasing the fluorescent product, threonine-[5-(2-aminoethyl)amino]naphthalene-1-sulfonic acid. Proteolytic activity was expressed as nanomoles of fluorescent product released at 22 degrees C/60 min, pH 4.5, and the release of 0.9 nmol product was equivalent to one hemoglobin proteolytic unit (O.D.A700 increase of 0.100) produced at 37 degrees C/60 min, pH 3.5. The aspartic proteinase inhibitor pepstatin had an IC50 of 27 nM when tested in a dose-response study with the purified enzyme. The apparent Ki for pepstatis was 2.9 nM. Several synthetic inhibitors of the enzymes were identified with IC50's in the nanomolar range. The most potent compound, A70450, was characterized as a fast, tight-binding inhibitor having an IC50 of 1.3 nM and apparent Ki of 0.17 nM.
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Affiliation(s)
- J O Capobianco
- Anti-Infective Research Division, Abbott Laboratories, Abbott Park, Illinois 60064-3500
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46
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García-Echeverría C, Rich DH. New intramolecularly quenched fluorogenic peptide substrates for the study of the kinetic specificity of papain. FEBS Lett 1992; 297:100-2. [PMID: 1551413 DOI: 10.1016/0014-5793(92)80336-f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A series of new substrates for determining the catalytic activity of cysteine proteinases is described. The rate of hydrolysis by papain was monitored by a fluorescence continuous assay based on internal resonance energy transfer using 5-[(2-aminoethyl)amino]naphtalene-1-sulfonic acid (EDANS) and 4-(4-dimethylaminophenylazo)benzoic acid (DABCYL) as fluorescent donor and quenching acceptor, respectively, in peptides with the general structure: DABCYL-Lys-Phe-Gly-Xxx-Ala-Ala-EDANS. The substrates were used to evaluate the effect of amino acid structure in the S1' position on the kinetic parameters for papain catalyzed hydrolysis.
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47
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Abstract
HIV produces a small , dimeric aspartyl protease which specifically cleaves the polyprotein precursors encoding the structural proteins and enzymes of the virus. This proteolytic activity is absolutely required for the production of mature, infectious virions and is therefore an attractive target for therapeutic intervention. This review summarizes the strategies and multidisciplinary efforts that have been applied to date to the identification of specific inhibitors of this critical viral enzyme. These inhibitors include rationally designed peptide substrate analogs, compounds conceived from tertiary structure information on the enzyme and natural products. Future directions in the discovery and development of HIV-1 protease inhibitors are also discussed.
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Affiliation(s)
- C Debouck
- Department of Molecular Genetics, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406
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48
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Edalji R, Holzman TF, Gubbins EJ. Active prorenin: evidence for the formation of a conformational variant of recombinant human prorenin. JOURNAL OF PROTEIN CHEMISTRY 1991; 10:403-6. [PMID: 1781885 DOI: 10.1007/bf01025254] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Using highly purified recombinant human prorenin, we report the first evidence for the formation of a stable, partially active, conformational variant of the recombinant proenzyme. The enzymatically active prorenin exhibits the following characteristics: (1) the proenzyme N-terminal sequence and molecular weight are maintained; (2) the active proenzyme is capable of cleaving a novel fluorogenic peptide substrate based on the sequence of human angiotensinogen and exhibits about 30% of mature renin specific activity for the fluorogenic substrate; (3) the active proenzyme conformation binds to, and can be eluted from, a pepstatin affinity column; and (4) the activity of the active proenzyme can be inhibited by a novel peptidomimetic renin inhibitor.
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Affiliation(s)
- R Edalji
- Protein Biochemistry, Pharmaceutical Discovery Research, Abbott Laboratories, Abbott Park, Illinois 60064
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