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Jian T, Su Q, Liu Y, Seoh HK, Houghton JE, Tai PC, Huang X. Structure-Based Virtual Screening of Helicobacter pylori SecA Inhibitors. IEEE Trans Nanobioscience 2023; 22:933-942. [PMID: 37030876 DOI: 10.1109/tnb.2023.3259946] [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: 04/10/2023]
Abstract
The human bacterial pathogen Helicobacter pylori causes a range of gastric diseases. The killing rate of Helicobacter pylori is declining year by year because of high antibiotics resistance. It is urgent to develop new target and novel anti- Helicobacter pylori drugs. As an "energy pump" for bacterial cells, SecA is essential for bacterial growth and drives bacterial protein transmembrane transport, moreover SecA is absent in mammals, all of which nominate SecA as an attractive antimicrobial target. Here, we provided a structure-based virtual screening method to screen the 3D-diversity natural-product-like screening library against SecA for novel anti- Helicobacter pylori inhibitors with novel scaffolds. In this study, homology modeling was used to construct the three-dimensional structure of Helicobacter pylori SecA. Two rounds of molecular docking were then used to find new small-molecule inhibitors of SecA, identifying six lead candidates that maintained key interactions with the binding pocket. After that, molecular dynamics simulations were used to explore more accurate ligand-receptor binding modes in states close to natural conditions. Encouragingly, all six compounds were relatively stable during the simulation. Apart from that the binding free energy calculation based on MM/PBSA demonstrated favorable results of < -13.642 kcal/mol. Finally, ADME-T analysis indicated that these compounds were also sufficiently druggable. All six compounds can be well combined with the crystal structure, which further facilitate the development of SecA inhibitors and lead compounds against Helicobacter pylori.
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2
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Kupriyanova EV, Sinetova MA, Leusenko AV, Voronkov AS, Los DA. A leader peptide of the extracellular cyanobacterial carbonic anhydrase ensures the efficient secretion of recombinant proteins in Escherichia coli. J Biotechnol 2021; 344:11-23. [PMID: 34921977 DOI: 10.1016/j.jbiotec.2021.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 10/19/2022]
Abstract
Several forms of EcaA protein, correspondent to the extracellular α-class carbonic anhydrase (CA) of cyanobacterium Crocosphaera subtropica ATCC 51142 were expressed in Escherichia coli. The recombinant proteins with no leader peptide (EcaA and its fusion with thioredoxin or glutathione S-transferase) were allocated inside cells in a full-length form; these cells did not display any extracellular CA activity. Soluble proteins (including that of periplasmic space) of E. coli cells that expressed both ЕсаА equipped with its native leader peptide (L-EcaA) as well as L-EcaA fused with thioredoxin or glutathione S-transferase at N-terminus, mainly contained the processed EcaA. The appearance of mature ЕсаА in outer layers of E. coli cells expressed leader peptide-containing forms of recombinant proteins, has been directly confirmed by immunofluorescent microscopy. Those cells also displayed high extracellular CA activity. In addition, the mature EcaA protein was detected in the culture medium. This suggests that cyanobacterial signal peptide is recognized by the secretory machinery and by the leader peptidase of E. coli even as a part of a fusion protein. The efficiency of EcaA leader peptide was comparable to that of PelB and TorA signal peptides, commonly used for biotechnological production of extracellular recombinant proteins in E. coli.
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Affiliation(s)
- Elena V Kupriyanova
- К.А. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
| | - Maria A Sinetova
- К.А. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Anna V Leusenko
- К.А. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Alexander S Voronkov
- К.А. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
| | - Dmitry A Los
- К.А. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia
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3
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Hu B, Rao MJ, Deng X, Pandey SS, Hendrich C, Ding F, Wang N, Xu Q. Molecular signatures between citrus and Candidatus Liberibacter asiaticus. PLoS Pathog 2021; 17:e1010071. [PMID: 34882744 PMCID: PMC8659345 DOI: 10.1371/journal.ppat.1010071] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Citrus Huanglongbing (HLB), also known as citrus greening, is one of the most devastating citrus diseases worldwide. Candidatus Liberibacter asiaticus (CLas) is the most prevalent strain associated with HLB, which is yet to be cultured in vitro. None of the commercial citrus cultivars are resistant to HLB. The pathosystem of Ca. Liberibacter is complex and remains a mystery. In this review, we focus on the recent progress in genomic research on the pathogen, the interaction of host and CLas, and the influence of CLas infection on the transcripts, proteins, and metabolism of the host. We have also focused on the identification of candidate genes for CLas pathogenicity or the improvements of HLB tolerance in citrus. In the end, we propose potentially promising areas for mechanistic studies of CLas pathogenicity, defense regulators, and genetic improvement for HLB tolerance/resistance in the future.
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Affiliation(s)
- Bin Hu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Ministry of Agriculture), Huazhong Agricultural University, Wuhan, Hubei, China
| | - Muhammad Junaid Rao
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Ministry of Agriculture), Huazhong Agricultural University, Wuhan, Hubei, China
| | - Xiuxin Deng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Ministry of Agriculture), Huazhong Agricultural University, Wuhan, Hubei, China
| | - Sheo Shankar Pandey
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America
| | - Connor Hendrich
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America
| | - Fang Ding
- Hubei Key Laboratory of Plant Pathology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Lake Alfred, Florida, United States of America
| | - Qiang Xu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (Ministry of Agriculture), Huazhong Agricultural University, Wuhan, Hubei, China
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4
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Thiouracil SecA inhibitors: bypassing the effects of efflux pumps and attenuating virulence factor secretion in MRSA and Bacillus anthracis. Med Chem Res 2021. [DOI: 10.1007/s00044-021-02750-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Cui P, Zhang D, Guo X, Ji S, Jiang Q. Synthesis and Antibacterial Evaluation of Thiouracil Derivatives Containing 1,2,4-Triazolo[1,5-a]Pyrimidine. LETT ORG CHEM 2021. [DOI: 10.2174/1570178617999200826164227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A series of new thiouracil compounds containing 1,2,4-triazolo[1,5-a]pyrimidine were designed
and synthesized. The in vitro antibacterial activities of the new compounds against Bacillus amyloliquefaciens,
Staphylococcus aureus and Bacillus subtilis were tested. The results showed that some
of the new compounds had strong inhibitory activities against the tested bacteria. At the concentration
of 50 μg/mL, the compound 12d had broad and the highest inhibitory activity with the 100% inhibition
against the three tested strains, the same as norfloxacin which was used as the control.
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Affiliation(s)
- Penglei Cui
- College of Science, Hebei Agricultural University, 071001 Baoding,China
| | - Di Zhang
- College of Food Science and Technology, Hebei Agricultural University, 071001 Baoding,China
| | - Xiumin Guo
- College of Science, Hebei Agricultural University, 071001 Baoding,China
| | - Shujing Ji
- College of Science, Hebei Agricultural University, 071001 Baoding,China
| | - Qingmei Jiang
- College of Science, Hebei Agricultural University, 071001 Baoding,China
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6
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Oswald J, Njenga R, Natriashvili A, Sarmah P, Koch HG. The Dynamic SecYEG Translocon. Front Mol Biosci 2021; 8:664241. [PMID: 33937339 PMCID: PMC8082313 DOI: 10.3389/fmolb.2021.664241] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
The spatial and temporal coordination of protein transport is an essential cornerstone of the bacterial adaptation to different environmental conditions. By adjusting the protein composition of extra-cytosolic compartments, like the inner and outer membranes or the periplasmic space, protein transport mechanisms help shaping protein homeostasis in response to various metabolic cues. The universally conserved SecYEG translocon acts at the center of bacterial protein transport and mediates the translocation of newly synthesized proteins into and across the cytoplasmic membrane. The ability of the SecYEG translocon to transport an enormous variety of different substrates is in part determined by its ability to interact with multiple targeting factors, chaperones and accessory proteins. These interactions are crucial for the assisted passage of newly synthesized proteins from the cytosol into the different bacterial compartments. In this review, we summarize the current knowledge about SecYEG-mediated protein transport, primarily in the model organism Escherichia coli, and describe the dynamic interaction of the SecYEG translocon with its multiple partner proteins. We furthermore highlight how protein transport is regulated and explore recent developments in using the SecYEG translocon as an antimicrobial target.
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Affiliation(s)
- Julia Oswald
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Robert Njenga
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Ana Natriashvili
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Pinku Sarmah
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany
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7
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8
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Multiple ways to kill bacteria via inhibiting novel cell wall or membrane targets. Future Med Chem 2020; 12:1253-1279. [PMID: 32538147 DOI: 10.4155/fmc-2020-0046] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The rise of antibiotic-resistant infections has been well documented and the need for novel antibiotics cannot be overemphasized. US FDA approved antibiotics target only a small fraction of bacterial cell wall or membrane components, well-validated antimicrobial targets. In this review, we highlight small molecules that inhibit relatively unexplored cell wall and membrane targets. Some of these targets include teichoic acids-related proteins (DltA, LtaS, TarG and TarO), lipid II, Mur family enzymes, components of LPS assembly (MsbA, LptA, LptB and LptD), penicillin-binding protein 2a in methicillin-resistant Staphylococcus aureus, outer membrane protein transport (such as LepB and BamA) and lipoprotein transport components (LspA, LolC, LolD and LolE). Inhibitors of SecA, cell division protein, FtsZ and compounds that kill persister cells via membrane targeting are also covered.
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9
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Bamba F, Jin J, Tai PC, Wang B. Synthesis and biological evaluation of novel 4-oxo-5-cyano thiouracil derivatives as SecA inhibitors. HETEROCYCL COMMUN 2020. [DOI: 10.1515/hc-2020-0100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractThe continuous emergence of drug-resistant strains of bacteria poses an urgent risk to human health and dictates the need for new antimicrobials. Along this line, we have been working on developing inhibitors of SecA, a key component of the bacterial Sec-dependent secretion machinery. Herein, we describe the synthesis and antimicrobial evaluation of 6-oxo-1,6-dihydropyrimidine-5-carbonitrile derivatives as potential SecA inhibitors.
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Affiliation(s)
- Fante Bamba
- Departments of Chemistry, Georgia State University, Atlanta, Georgia 30303, USA
- Laboratoire de Chimie Organique et des Substances Naturelles, Université Félix Houphouët-Boigny, 22 Bp 582 Abidjan 22, AbidjanCote d‘Ivoire
| | - Jinshan Jin
- Departments of Biology, Georgia State University, Atlanta, Georgia 30303, USA
| | - Phang C. Tai
- Departments of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30303, USA
| | - Binghe Wang
- Departments of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30303, USA
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10
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Jin J, Hsieh YH, Chaudhary AS, Cui J, Houghton JE, Sui SF, Wang B, Tai PC. SecA inhibitors as potential antimicrobial agents: differential actions on SecA-only and SecA-SecYEG protein-conducting channels. FEMS Microbiol Lett 2018; 365:5037921. [PMID: 30007321 PMCID: PMC7190897 DOI: 10.1093/femsle/fny145] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022] Open
Abstract
Sec-dependent protein translocation is an essential process in bacteria. SecA is a key component of the translocation machinery and has multiple domains that interact with various ligands. SecA acts as an ATPase motor to drive the precursor protein/peptide through the SecYEG protein translocation channels. As SecA is unique to bacteria and there is no mammalian counterpart, it is an ideal target for the development of new antimicrobials. Several reviews detail the assays for ATPase and protein translocation, as well as the search for SecA inhibitors. Recent studies have shown that, in addition to the SecA-SecYEG translocation channels, there are SecA-only channels in the lipid bilayers, which function independently from the SecYEG machinery. This mini-review focuses on recent advances on the newly developed SecA inhibitors that allow the evaluation of their potential as antimicrobial agents, as well as a fundamental understanding of mechanisms of SecA function(s). These SecA inhibitors abrogate the effects of efflux pumps in both Gram-positive and Gram-negative bacteria. We also discuss recent findings that SecA binds to ribosomes and nascent peptides, which suggest other roles of SecA. A model for the multiple roles of SecA is presented.
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Affiliation(s)
- Jinshan Jin
- Department of Biology, Center for Biotechnology and Drug Design and Georgia State University, Atlanta, GA 30303, USA
| | - Ying-Hsin Hsieh
- Department of Biology, Center for Biotechnology and Drug Design and Georgia State University, Atlanta, GA 30303, USA
| | - Arpana S Chaudhary
- Department of Chemistry, Center for Biotechnology and Drug Design and Georgia State University, P.O. Box 3965, Atlanta, GA 30303, USA
| | - Jianmei Cui
- Department of Chemistry, Center for Biotechnology and Drug Design and Georgia State University, P.O. Box 3965, Atlanta, GA 30303, USA
| | - John E Houghton
- Department of Biology, Center for Biotechnology and Drug Design and Georgia State University, Atlanta, GA 30303, USA
| | - Sen-fang Sui
- State Key Laboratory of Membrane Biology, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Binghe Wang
- Department of Chemistry, Center for Biotechnology and Drug Design and Georgia State University, P.O. Box 3965, Atlanta, GA 30303, USA
| | - Phang C Tai
- Department of Biology, Center for Biotechnology and Drug Design and Georgia State University, Atlanta, GA 30303, USA
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11
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Cui P, Li X, Zhu M, Wang B, Liu J, Chen H. Design, synthesis and antibacterial activities of thiouracil derivatives containing acyl thiourea as SecA inhibitors. Bioorg Med Chem Lett 2017; 27:2234-2237. [DOI: 10.1016/j.bmcl.2016.11.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/11/2016] [Accepted: 11/22/2016] [Indexed: 12/28/2022]
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12
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Cui P, Li X, Zhu M, Wang B, Liu J, Chen H. Design, synthesis and antimicrobial activities of thiouracil derivatives containing triazolo-thiadiazole as SecA inhibitors. Eur J Med Chem 2016; 127:159-165. [PMID: 28039774 DOI: 10.1016/j.ejmech.2016.12.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 12/23/2016] [Accepted: 12/24/2016] [Indexed: 11/28/2022]
Abstract
A series of novel thiouracil derivatives containing a triazolo-thiadiazole moiety (7a-7l) have been synthesized by structural modifications on a lead SecA inhibitor, 2. All the compounds have been evaluated for their antibacterial activities against Bacillus amyloliquefaciens, Staphylococcus aureus, and Bacillus subtilis. Compounds 7d and 7g were also tested for their inhibitory activities against SecA ATPase due to their promising antimicrobial activities. The inhibitory activity of compound 7d was found to be higher than that of 2. Molecular docking work suggests that compound 7d might bind at a pocket close to the ATPase ATP-binding domain.
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Affiliation(s)
- Penglei Cui
- Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China; College of Science, Agricultural University of Hebei, Baoding 071001, China
| | - Xiaoliu Li
- Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
| | - Mengyuan Zhu
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302-4098, USA
| | - Binghe Wang
- Department of Chemistry and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302-4098, USA
| | - Jing Liu
- College of Veterinary Medicine, Agricultural University of Hebei, Baoding 071001, China
| | - Hua Chen
- Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China.
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13
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Jin J, Hsieh YH, Cui J, Damera K, Dai C, Chaudhary AS, Zhang H, Yang H, Cao N, Jiang C, Vaara M, Wang B, Tai PC. Using Chemical Probes to Assess the Feasibility of Targeting SecA for Developing Antimicrobial Agents against Gram-Negative Bacteria. ChemMedChem 2016; 11:2511-2521. [PMID: 27753464 PMCID: PMC5189635 DOI: 10.1002/cmdc.201600421] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 09/25/2016] [Indexed: 11/07/2022]
Abstract
With the widespread emergence of drug resistance, there is an urgent need to search for new antimicrobials, especially those against Gram-negative bacteria. Along this line, the identification of viable targets is a critical first step. The protein translocase SecA is commonly believed to be an excellent target for the development of broad-spectrum antimicrobials. In recent years, we developed three structural classes of SecA inhibitors that have proven to be very effective against Gram-positive bacteria. However, we have not achieved the same level of success against Gram-negative bacteria, despite the potent inhibition of SecA in enzyme assays by the same inhibitors. In this study, we use representative inhibitors as chemical probes to gain an understanding as to why these inhibitors were not effective against Gram-negative bacteria. The results validate our initial postulation that the major difference in effectiveness against Gram-positive and Gram-negative bacteria is in the additional permeability barrier posed by the outer membrane of Gram-negative bacteria. We also found that the expression of efflux pumps, which are responsible for multidrug resistance (MDR), have no effect on the effectiveness of these SecA inhibitors. Identification of an inhibitor-resistant mutant and complementation tests of the plasmids containing secA in a secAts mutant showed that a single secA-azi-9 mutation increased the resistance, providing genetic evidence that SecA is indeed the target of these inhibitors in bacteria. Such results strongly suggest SecA as an excellent target for developing effective antimicrobials against Gram-negative bacteria with the intrinsic ability to overcome MDR. A key future research direction should be the optimization of membrane permeability.
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Affiliation(s)
- Jinshan Jin
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Ying-Hsin Hsieh
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Jianmei Cui
- Department of Chemistry, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Krishna Damera
- Department of Chemistry, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Chaofeng Dai
- Department of Chemistry, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Arpana S. Chaudhary
- Department of Chemistry, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Hao Zhang
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Hsiuchin Yang
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Nannan Cao
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Chun Jiang
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Martti Vaara
- Division of Clinical Microbiology, Helsinki University Hospital, FI-00029 HUSLAB, Helsinki, Finland, and Northern Antibiotics Ltd, FI-00720, Helsinki, Finland
| | - Binghe Wang
- Department of Chemistry, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
| | - Phang C. Tai
- Department of Biology, Center for Biotechnology and Drug Design, and Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303
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14
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Abstract
There is a consensus in the medical profession of the pressing need for novel antimicrobial agents due to issues related to drug resistance. In practice, solutions to this problem to a large degree lie with the identification of new and vital targets in bacteria and subsequently designing their inhibitors. We consider SecA a very promising antimicrobial target. In this review, we compile and analyze information available on SecA to show that inhibition of SecA has a multitude of consequences. Furthermore, we discuss issues critical to the design and evaluation of SecA inhibitors.
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15
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Cui J, Jin J, Chaudhary AS, Hsieh YH, Zhang H, Dai C, Damera K, Chen W, Tai PC, Wang B. Design, Synthesis and Evaluation of Triazole-Pyrimidine Analogues as SecA Inhibitors. ChemMedChem 2016; 11:43-56. [PMID: 26607404 PMCID: PMC4778717 DOI: 10.1002/cmdc.201500447] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Indexed: 01/15/2023]
Abstract
SecA, a key component of the bacterial Sec-dependent secretion pathway, is an attractive target for the development of new antimicrobial agents. Through a combination of virtual screening and experimental exploration of the surrounding chemical space, we identified a hit bistriazole SecA inhibitor, SCA-21, and studied a series of analogues by systematic dissections of the core scaffold. Evaluation of these analogues allowed us to establish an initial structure-activity relationship in SecA inhibition. The best compounds in this group are potent inhibitors of SecA-dependent protein-conducting channel activity and protein translocation activity at low- to sub-micromolar concentrations. They also have minimal inhibitory concentration (MIC) values against various strains of bacteria that correlate well with the SecA and protein translocation inhibition data. These compounds are effective against methicillin-resistant Staphylococcus aureus strains with various levels of efflux pump activity, indicating the capacity of SecA inhibitors to null the effect of multidrug resistance. Results from studies of drug-affinity-responsive target stability and protein pull-down assays are consistent with SecA as a target for these compounds.
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Affiliation(s)
- Jianmei Cui
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Jinshan Jin
- Department of Biology, Center for Biotechnology and Drug Design, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30303, USA
| | | | - Ying-hsin Hsieh
- Department of Biology, Center for Biotechnology and Drug Design, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30303, USA
| | - Hao Zhang
- Department of Biology, Center for Biotechnology and Drug Design, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30303, USA
| | - Chaofeng Dai
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Krishna Damera
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Weixuan Chen
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
| | - Phang C Tai
- Department of Biology, Center for Biotechnology and Drug Design, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, 30303, USA.
| | - Binghe Wang
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA.
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16
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Dwivedi UN, Tiwari S, Singh P, Singh S, Awasthi M, Pandey VP. Treponema pallidum putative novel drug target identification and validation: rethinking syphilis therapeutics with plant-derived terpenoids. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2015; 19:104-14. [PMID: 25683888 DOI: 10.1089/omi.2014.0154] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Syphilis, a slow progressive and the third most common sexually transmitted disease found worldwide, is caused by a spirochete gram negative bacteria Treponema pallidum. Emergence of antibiotic resistant T. pallidum has led to a search for novel drugs and their targets. Subtractive genomics analyses of pathogen T. pallidum and host Homo sapiens resulted in identification of 126 proteins essential for survival and viability of the pathogen. Metabolic pathway analyses of these essential proteins led to discovery of nineteen proteins distributed among six metabolic pathways unique to T. pallidum. One hundred plant-derived terpenoids, as potential therapeutic molecules against T. pallidum, were screened for their drug likeness and ADMET (absorption, distribution, metabolism, and toxicity) properties. Subsequently the resulting nine terpenoids were docked with five unique T. pallidum targets through molecular modeling approaches. Out of five targets analyzed, D-alanine:D-alanine ligase was found to be the most promising target, while terpenoid salvicine was the most potent inhibitor. A comparison of the inhibitory potential of the best docked readily available natural compound, namely pomiferin (flavonoid) with that of the best docked terpenoid salvicine, revealed that salvicine was a more potent inhibitor than that of pomiferin. To the best of our knowledge, this is the first report of a terpenoid as a potential therapeutic molecule against T. pallidum with D-alanine:D-alanine ligase as a novel target. Further studies are warranted to evaluate and explore the potential clinical ramifications of these findings in relation to syphilis that has public health importance worldwide.
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Affiliation(s)
- Upendra N Dwivedi
- Department of Biochemistry, Centre of Excellence in Bioinformatics, Bioinformatics Infrastructure Facility, University of Lucknow , Lucknow, U.P., India
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Identification of small-molecule inhibitors against SecA by structure-based virtual ligand screening. J Antibiot (Tokyo) 2015; 68:666-73. [PMID: 25990955 DOI: 10.1038/ja.2015.53] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 03/17/2015] [Accepted: 04/13/2015] [Indexed: 12/28/2022]
Abstract
The rapid rise of antibiotic-resistant bacteria is one of the major concerns in modern medicine. Therefore, to treat bacterial infections, there is an urgent need for new antibacterials-preferably directed against alternative bacterial targets. One such potential target is the preprotein translocation motor SecA. SecA is a peripheral membrane ATPase and a key component of the Sec secretion pathway, the major route for bacterial protein export across or into the cytoplasmic membrane. As SecA is essential for bacterial viability, ubiquitous and highly conserved in bacteria, but not present in eukaryotic cells, it represents an attractive antibacterial target. Using an in silico approach, we have defined several potentially druggable and conserved pockets on the surface of SecA. We show that three of these potentially druggable sites are important for SecA function. A starting collection of ~500 000 commercially available small-molecules was virtually screened against a predicted druggable pocket in the preprotein-binding domain of Escherichia coli SecA using a multi-step virtual ligand screening protocol. The 1040 top-scoring molecules were tested in vitro for inhibition of the translocation ATPase activity of E. coli SecA. Five inhibitors of the translocation ATPase, and not of basal or membrane ATPase, were identified with IC50 values <65 μm. The most potent inhibitor showed an IC50 of 24 μm. The antimicrobial activity was determined for the five most potent SecA inhibitors. Two compounds were found to possess weak antibacterial activity (IC50 ~198 μm) against E. coli, whereas some compounds showed moderate antibacterial activity (IC50 ~100 μm) against Staphylococcus aureus.
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Chaudhary AS, Jin J, Chen W, Tai PC, Wang B. Design, syntheses and evaluation of 4-oxo-5-cyano thiouracils as SecA inhibitors. Bioorg Med Chem 2014; 23:105-17. [PMID: 25498235 DOI: 10.1016/j.bmc.2014.11.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 11/02/2014] [Accepted: 11/14/2014] [Indexed: 11/26/2022]
Abstract
Protein translocation is essential for bacterial survival and the most important translocation mechanism is the secretion (Sec) pathway in which SecA is a central core driving force. Thus targeting SecA is a promising strategy for developing novel antibacterial therapeutics. Herein, we report the syntheses and evaluation of a series of nearly 60 4-oxo-5-cyano thiouracil derivatives based upon our previously reported core pyrimidine structure. Introduction of polar group such as -N3 and linker groups such as -CH2-O- enhanced the potency several fold. Apart from being potential antibacterial agents, these inhibitors can be indispensable tools for biologists to probe the mechanism of protein translocation via the SecA machinery in bacteria.
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Affiliation(s)
- Arpana S Chaudhary
- College of Arts and Sciences, Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Jinshan Jin
- Department of Biology, Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, USA
| | - Weixuan Chen
- College of Arts and Sciences, Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA
| | - Phang C Tai
- Department of Biology, Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, USA.
| | - Binghe Wang
- College of Arts and Sciences, Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
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19
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Hsieh YH, Huang YJ, Jin JS, Yu L, Yang H, Jiang C, Wang B, Tai PC. Mechanisms of Rose Bengal inhibition on SecA ATPase and ion channel activities. Biochem Biophys Res Commun 2014; 454:308-12. [PMID: 25450394 DOI: 10.1016/j.bbrc.2014.10.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
Abstract
SecA is an essential protein possessing ATPase activity in bacterial protein translocation for which Rose Bengal (RB) is the first reported sub-micromolar inhibitor in ATPase activity and protein translocation. Here, we examined the mechanisms of inhibition on various forms of SecA ATPase by conventional enzymatic assays, and by monitoring the SecA-dependent channel activity in the semi-physiological system in cells. We build on the previous observation that SecA with liposomes form active protein-conducting channels in the oocytes. Such ion channel activity is enhanced by purified Escherichia coli SecYEG-SecDF·YajC liposome complexes. Inhibition by RB could be monitored, providing correlation of in vitro activity and intact cell functionality. In this work, we found the intrinsic SecA ATPase is inhibited by RB competitively at low ATP concentration, and non-competitively at high ATP concentrations while the translocation ATPase with precursors and SecYEG is inhibited non-competitively by RB. The Inhibition by RB on SecA channel activity in the oocytes with exogenous ATP-Mg(2+), mimicking translocation ATPase activity, is also non-competitive. The non-competitive inhibition on channel activity has also been observed with SecA from other bacteria which otherwise would be difficult to examine without the cognate precursors and membranes.
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Affiliation(s)
- Ying-Hsin Hsieh
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Ying-Ju Huang
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Jin-Shan Jin
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Liyan Yu
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Hsiuchin Yang
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Chun Jiang
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Binghe Wang
- Department of Chemistry, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States
| | - Phang C Tai
- Department of Biology, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, United States.
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Rao C V S, De Waelheyns E, Economou A, Anné J. Antibiotic targeting of the bacterial secretory pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1762-83. [PMID: 24534745 DOI: 10.1016/j.bbamcr.2014.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/27/2014] [Accepted: 02/06/2014] [Indexed: 02/06/2023]
Abstract
Finding new, effective antibiotics is a challenging research area driven by novel approaches required to tackle unconventional targets. In this review we focus on the bacterial protein secretion pathway as a target for eliminating or disarming pathogens. We discuss the latest developments in targeting the Sec-pathway for novel antibiotics focusing on two key components: SecA, the ATP-driven motor protein responsible for driving preproteins across the cytoplasmic membrane and the Type I signal peptidase that is responsible for the removal of the signal peptide allowing the release of the mature protein from the membrane. We take a bird's-eye view of other potential targets in the Sec-pathway as well as other Sec-dependent or Sec-independent protein secretion pathways as targets for the development of novel antibiotics. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Smitha Rao C V
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
| | - Evelien De Waelheyns
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
| | - Anastassios Economou
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium; Institute of Molecular Biology and Biotechnology, FORTH, University of Crete, P.O. Box 1385, GR-711 10 Iraklio, Crete, Greece; Department of Biology, University of Crete, P.O. Box 1385, GR-71110 Iraklio, Crete, Greece.
| | - Jozef Anné
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
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21
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Design and bio-evaluation of indole derivatives as potent Kv1.5 inhibitors. Bioorg Med Chem 2013; 21:6466-76. [DOI: 10.1016/j.bmc.2013.08.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 01/29/2023]
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22
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Cui J, Jin J, Hsieh YH, Yang H, Ke B, Damera K, Tai PC, Wang B. Design, Synthesis and Biological Evaluation of Rose Bengal Analogues as SecA Inhibitors. ChemMedChem 2013; 8:1384-93. [DOI: 10.1002/cmdc.201300216] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Indexed: 11/06/2022]
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23
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Mascini M, Montesano C, Sergi M, Perez G, De Cicco M, Curini R, Compagnone D. Peptides trapping cocaine: docking simulation and experimental screening by solid phase extraction followed by liquid chromatography mass spectrometry in plasma samples. Anal Chim Acta 2013; 772:40-6. [DOI: 10.1016/j.aca.2013.02.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 02/15/2013] [Accepted: 02/19/2013] [Indexed: 11/29/2022]
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24
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Zhu P, Peng H, Ni N, Wang B, Li M. Novel AI-2 quorum sensing inhibitors in Vibrio harveyi identified through structure-based virtual screening. Bioorg Med Chem Lett 2012; 22:6413-7. [PMID: 22963763 DOI: 10.1016/j.bmcl.2012.08.062] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 07/21/2012] [Accepted: 08/16/2012] [Indexed: 12/11/2022]
Abstract
In this letter, a high-throughput virtual screening was accomplished to identify potent inhibitors against AI-2 quorum sensing on the basis of Vibrio harveyi LuxPQ crystal structure. Seven compounds were found to inhibit AI-2 quorum sensing with IC(50) values in the micromolar range, and presented low cytotoxicity or no cytotoxicity in V. harveyi.
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Affiliation(s)
- Peng Zhu
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology of Natural Products (MOE), School of Pharmacy, Shandong University, Jinan, Shandong, PR China
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25
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Akula N, Trivedi P, Han FQ, Wang N. Identification of small molecule inhibitors against SecA of Candidatus Liberibacter asiaticus by structure based design. Eur J Med Chem 2012; 54:919-24. [PMID: 22703844 DOI: 10.1016/j.ejmech.2012.05.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/20/2012] [Accepted: 05/23/2012] [Indexed: 11/17/2022]
Abstract
Huanglongbing is the most devastating disease of citrus caused by Candidatus Liberibacter asiaticus (Las). In the present study, we report the discovery of novel small molecule inhibitors against SecA ATPase of Las by using structure based design methods. We built the homology model of SecA protein structure of Las based on the SecA of Escherichia coli. The model was used for in-silico screening of commercially available compounds from ZINC database. Using the glide flexible molecular docking method, twenty structures were chosen for in vitro studies. Five compounds were found to inhibit the ATPase activity of SecA of Las at nano molar concentrations and showed antimicrobial activities against Agrobacterium tumefaciens with MBC ranging from 128 to 256 μg/mL. These compounds appear to be suitable as lead compounds for further development of antimicrobial compounds against Las.
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Affiliation(s)
- Nagaraju Akula
- Citrus Research & Education Center, Department of Microbiology and Cell Science, University of Florida, 700 Experiment Station Rd., Lake Alfred, FL 33850, USA
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26
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Huang YJ, Wang H, Gao FB, Li M, Yang H, Wang B, Tai PC. Fluorescein analogues inhibit SecA ATPase: the first sub-micromolar inhibitor of bacterial protein translocation. ChemMedChem 2012; 7:571-7. [PMID: 22354575 DOI: 10.1002/cmdc.201100594] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Indexed: 11/10/2022]
Abstract
SecA is a central component of the general secretion system that is essential for bacterial growth and thus an ideal target for antimicrobial agents. A series of fluorescein analogues were first screened against the ATPase activity using the truncated unregulated SecA catalytic domain. Rose bengal (RB) and erythrosin B (EB) were found to be potent inhibitors SecA with IC(50) values of 0.5 μM and 2 μM, respectively. RB and EB inhibit the catalytic SecA ATPase more effectively than the F(1) F(0) -proton ATPase. We used three assays to test the effect of these compounds on full-length SecA ATPase: in solution (intrinsic ATPase), in membrane preparation, and translocation ATPase. RB and EB show the following trend in terms of IC(50) values: translocation ATPase<membrane ATPase<intrinsic ATPase. Very importantly, the potency of these fluorescein analogues in inhibiting the truncated SecA ATPase correlates with their ability to inhibit the biologically relevant protein translocation activity of SecA. The in vitro translocation of proOmpA precursors into membrane vesicles is strongly inhibited by RB with IC(50) values of approximately 0.25 μM, making RB the most potent inhibitor of SecA ATPase and SecA-dependent protein translocation reported thus far. The ability of these compounds to inhibit SecA also directly translates into antibacterial effects. Our findings show the value of fluorescein analogues as probes for mechanistic studies of SecA functions and for the potential development of new antimicrobial agents with SecA as the target.
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Affiliation(s)
- Ying-Ju Huang
- Department of Biology, Georgia State University, 490 Petit Science Center, 161 Jesse Hill Jr. Drive, Atlanta, GA 30303, USA
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27
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Crowther GJ, Quadri SA, Shannon-Alferes BJ, Van Voorhis WC, Rosen H. A mechanism-based whole-cell screening assay to identify inhibitors of protein export in Escherichia coli by the Sec pathway. ACTA ACUST UNITED AC 2012; 17:535-41. [PMID: 22233648 DOI: 10.1177/1087057111431606] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
More than 20% of bacterial proteins are noncytoplasmic, and most of these pass through the SecYEG channel en route to the periplasm, cell membrane, or surrounding environment. The Sec pathway, encompassing SecYEG and several associated proteins (SecA, SecB, YidC, SecDFYajC), is of interest as a potential drug target because it is distinct from targets of current drugs, is essential for bacterial growth, and exhibits dissimilarities in eukaryotes and bacteria that increase the likelihood of selectively inhibiting the microbial pathway. As a step toward validating the pathway as a drug target, we have adapted a mechanism-based whole-cell assay in a manner suitable for high-throughput screening (HTS). The assay uses an engineered strain of Escherichia coli that accumulates beta-galactosidase (β-gal) in its cytoplasm if translocation through SecYEG is blocked. The assay should facilitate rapid identification of compounds that specifically block the Sec pathway because widely, toxic compounds and nonspecific protein synthesis inhibitors prevent β-gal production and thus do not register as hits. Testing of current antibiotics confirmed that they do not generally act through the Sec pathway. A mini-screen of 800 compounds indicated the assay's readiness for larger screening projects.
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28
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Page MGP. The role of the outer membrane of Gram-negative bacteria in antibiotic resistance: Ajax' shield or Achilles' heel? Handb Exp Pharmacol 2012:67-86. [PMID: 23090596 DOI: 10.1007/978-3-642-28951-4_5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There has been an enormous increase in our knowledge of the fundamental steps in the biosynthesis and assembly of the outer membrane of Gram-negative bacteria. Lipopolysaccharide is a major component of the outer membrane of Gram-negative bacteria as is peptidoglycan. Porins, efflux pumps and other transport proteins of the outer membrane are also present. It is clear that there are numerous essential proteins that have the potential to be targets for novel antimicrobial agents. Progress, however, has been slow. Much of the emphasis has been on cytoplasmic processes that were better understood earlier on, but have the drawback that two penetration barriers, with different permeability properties, have to be crossed. With the increased understanding of the late-stage events occurring in the periplasm, it may be possible to shift focus to these more accessible targets. Nevertheless, getting drugs across the outer membrane will remain a challenge to the ingenuity of the medicinal chemist.
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29
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Traffic jam at the bacterial sec translocase: targeting the SecA nanomotor by small-molecule inhibitors. ACTA ACUST UNITED AC 2011; 18:685-98. [PMID: 21700205 DOI: 10.1016/j.chembiol.2011.04.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 04/27/2011] [Accepted: 04/28/2011] [Indexed: 11/20/2022]
Abstract
The rapid rise of drug-resistant bacteria is one of the most serious unmet medical needs facing the world. Despite this increasing problem of antibiotic resistance, the number of different antibiotics available for the treatment of serious infections is dwindling. Therefore, there is an urgent need for new antibacterial drugs, preferably with novel modes of action to potentially avoid cross-resistance with existing antibacterial agents. In recent years, increasing attention has been paid to bacterial protein secretion as a potential antibacterial target. Among the different protein secretion pathways that are present in bacterial pathogens, the general protein secretory (Sec) pathway is widely considered as an attractive target for antibacterial therapy. One of the key components of the Sec pathway is the peripheral membrane ATPase SecA, which provides the energy for the translocation of preproteins across the bacterial cytoplasmic membrane. In this review, we will provide an overview of research efforts on the discovery and development of small-molecule SecA inhibitors. Furthermore, recent advances on the structure and function of SecA and their potential impact on antibacterial drug discovery will be discussed.
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30
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Akula N, Zheng H, Han FQ, Wang N. Discovery of novel SecA inhibitors of Candidatus Liberibacter asiaticus by structure based design. Bioorg Med Chem Lett 2011; 21:4183-8. [DOI: 10.1016/j.bmcl.2011.05.086] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2011] [Revised: 05/22/2011] [Accepted: 05/23/2011] [Indexed: 11/27/2022]
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31
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Bini A, Mascini M, Mascini M, Turner APF. Selection of thrombin-binding aptamers by using computational approach for aptasensor application. Biosens Bioelectron 2011; 26:4411-6. [PMID: 21636260 DOI: 10.1016/j.bios.2011.04.053] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/21/2011] [Accepted: 04/28/2011] [Indexed: 10/18/2022]
Abstract
The possibility of introducing a computationally assisted method to study aptamer-protein interaction was evaluated with the aim of streamlining the screening and selection of new aptamers. Starting from information on the 15-mer (5'-GGTTGGTGTGGTTGG-3') thrombin binding aptamer (TBA), a library of mutated DNA sequences (994 elements) was generated and screened using shapegauss a shape-based scoring function from openeye software to generate computationally derived binding scores. The TBA and three other mutated oligonucleotides, selected on the basis of their binding score (best, medium, worst), were incorporated into surface plasmon resonance (SPR) biosensors. By reducing the ionic strength (binding buffer, 50 mM TrisHCl pH 7.4, 140 mM NaCl, 1mM MgCl₂, diluted 1:50) in order to match the simulated condition, the analytical performances of the four oligonucleotide sequences were compared using signal amplitude, sensitivity (slope), linearity (R²) and reproducibility (CVav %). The experimental results were in agreement with the simulation findings.
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Affiliation(s)
- Alessandra Bini
- Dipartimento di Chimica, Università degli Studi di Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino, Italy
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32
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Feltcher ME, Sullivan JT, Braunstein M. Protein export systems of Mycobacterium tuberculosis: novel targets for drug development? Future Microbiol 2011; 5:1581-97. [PMID: 21073315 DOI: 10.2217/fmb.10.112] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Protein export is essential in all bacteria and many bacterial pathogens depend on specialized protein export systems for virulence. In Mycobacterium tuberculosis, the etiological agent of the disease tuberculosis, the conserved general secretion (Sec) and twin-arginine translocation (Tat) pathways perform the bulk of protein export and are both essential. M. tuberculosis also has specialized export pathways that transport specific subsets of proteins. One such pathway is the accessory SecA2 system, which is important for M. tuberculosis virulence. There are also specialized ESX export systems that function in virulence (ESX-1) or essential physiologic processes (ESX-3). The increasing prevalence of drug-resistant M. tuberculosis strains makes the development of novel drugs for tuberculosis an urgent priority. In this article, we discuss our current understanding of the protein export systems of M. tuberculosis and consider the potential of these pathways to be novel targets for tuberculosis drugs.
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Affiliation(s)
- Meghan E Feltcher
- Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, CB # 7290, Chapel Hill, NC 27599, USA
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33
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Segers K, Klaassen H, Economou A, Chaltin P, Anné J. Development of a high-throughput screening assay for the discovery of small-molecule SecA inhibitors. Anal Biochem 2011; 413:90-6. [PMID: 21338570 DOI: 10.1016/j.ab.2011.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 02/08/2011] [Accepted: 02/08/2011] [Indexed: 10/18/2022]
Abstract
A major pathway for bacterial preprotein translocation is provided by the Sec-dependent preprotein translocation pathway. Proteins destined for Sec-dependent translocation are synthesized as preproteins with an N-terminal signal peptide, which targets them to the SecYEG translocase channel. The driving force for the translocation reaction is provided by the peripheral membrane ATPase SecA, which couples the hydrolysis of ATP to the stepwise transport of unfolded preproteins across the bacterial membrane. Since SecA is essential, highly conserved among bacterial species, and has no close human homologues, it represents a promising target for antibacterial chemotherapy. However, high-throughput screening (HTS) campaigns to identify SecA inhibitors are hampered by the low intrinsic ATPase activity of SecA and the requirement of hydrophobic membranes for measuring the membrane or translocation ATPase activity of SecA. To address this issue, we have developed a colorimetric high-throughput screening assay in a 384-well format, employing an Escherichia coli (E. coli) SecA mutant with elevated intrinsic ATPase activity. The assay was applied for screening of a chemical library consisting of ~27,000 compounds and proved to be highly reliable (average Z' factor of 0.89). In conclusion, a robust HTS assay has been established that will facilitate the search for novel SecA inhibitors.
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Affiliation(s)
- Kenneth Segers
- Laboratory of Bacteriology, Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroederstraat 10, 3000 Leuven, Belgium.
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Wu J, Wang J, Li M, Yang Y, Wang B, Zheng YG. Small molecule inhibitors of histone acetyltransferase Tip60. Bioorg Chem 2011; 39:53-8. [PMID: 21186043 PMCID: PMC3144758 DOI: 10.1016/j.bioorg.2010.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 11/26/2010] [Accepted: 11/29/2010] [Indexed: 12/13/2022]
Abstract
Tip60 is a key member of the MYST family of histone acetyltransferases and involved in a broad spectrum of cellular pathways and disease conditions. So far, small molecule inhibitors of Tip60 and other members of MYST HATs are rarely reported. To discover new small molecule inhibitors of Tip60 as mechanistic tools for functional study and as chemical leads for therapeutic development, we performed virtual screening using the crystal structure of Esa1 (the yeast homolog of Tip60) on a small molecule library database. Radioactive acetylation assays were carried out to further evaluate the virtual screen hits. Several compounds with new structural scaffolds were identified with micromolar inhibition potency for Tip60 from the biochemical studies. Further, computer modeling and kinetic assays suggest that these molecules target the acetyl-CoA binding site in Tip60. These new inhibitors provide valuable chemical hits to develop further potent inhibitors for the MYST HATs.
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Affiliation(s)
- Jiang Wu
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
| | - Juxian Wang
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
| | - Minyong Li
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
| | - Yutao Yang
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
| | - Binghe Wang
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
| | - Y. George Zheng
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, PO Box 4098, Atlanta, GA 30302, USA
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Synthesis of novel 5-amino-thiazolo[4,5-d]pyrimidines as E. coli and S. aureus SecA inhibitors. Bioorg Med Chem 2011; 19:702-14. [DOI: 10.1016/j.bmc.2010.10.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/11/2010] [Accepted: 10/12/2010] [Indexed: 11/22/2022]
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Yang Q, Fedida D, Xu H, Wang B, Du L, Wang X, Li M, You Q. Structure-based virtual screening and electrophysiological evaluation of new chemotypes of K(v)1.5 channel blockers. ChemMedChem 2010; 5:1353-8. [PMID: 20540065 DOI: 10.1002/cmdc.201000162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Atrial fibrillation (AF) is the most prevalent nonfatal cardiac rhythm disorder associated with an increased risk of heart failure and stroke. Considering the ventricular side effects induced by anti-arrhythmic agents in current use, K(v)1.5 channel blockers have attracted a great deal of deliberation owing to their selective actions on atrial electrophysiology. Herein we report new chemotypes of K(v)1.5 channel blockers that were identified through a combination of structure-based virtual screening and in silico druglike property prediction including six scoring functions, as well as electrophysiological evaluation. Among them, five of the 18 compounds exhibited >50 % blockade ratio at 10 microM, and have structural features different from conventional K(v)1.5 channel blockers. These novel scaffolds could serve as hits for further optimization and SAR studies for the discovery of selective agents to treat AF.
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Affiliation(s)
- Qian Yang
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, Jiangsu, China
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37
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Feng Y, Li M, Wang B, Zheng YG. Discovery and Mechanistic Study of a Class of Protein Arginine Methylation Inhibitors. J Med Chem 2010; 53:6028-39. [DOI: 10.1021/jm100416n] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- You Feng
- Department of Chemistry, Center for Biotechnology and Drug Design, Georgia State University, P.O. Box 4098, Atlanta, Georgia 30302
| | - Mingyong Li
- Department of Chemistry, Center for Biotechnology and Drug Design, Georgia State University, P.O. Box 4098, Atlanta, Georgia 30302
| | - Binghe Wang
- Department of Chemistry, Center for Biotechnology and Drug Design, Georgia State University, P.O. Box 4098, Atlanta, Georgia 30302
| | - Yujun George Zheng
- Department of Chemistry, Center for Biotechnology and Drug Design, Georgia State University, P.O. Box 4098, Atlanta, Georgia 30302
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38
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Chemical validation of phosphodiesterase C as a chemotherapeutic target in Trypanosoma cruzi, the etiological agent of Chagas' disease. Antimicrob Agents Chemother 2010; 54:3738-45. [PMID: 20625148 DOI: 10.1128/aac.00313-10] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trypanosoma cruzi phosphodiesterase (PDE) C (TcrPDEC), a novel and rather unusual PDE in which, unlike all other class I PDEs, the catalytic domain is localized in the middle of the polypeptide chain, is able to hydrolyze cyclic GMP (cGMP), although it prefers cyclic AMP (cAMP), and has a FYVE-type domain in its N-terminal region (S. Kunz et al., FEBS J. 272:6412-6422, 2005). TcrPDEC shows homology to the mammalian PDE4 family members. PDE4 inhibitors are currently under development for the treatment of inflammatory diseases, such as asthma, chronic pulmonary diseases, and psoriasis, and for treating depression and serving as cognitive enhancers. We therefore tested a number of compounds originally synthesized as potential PDE4 inhibitors on T. cruzi amastigote growth, and we obtained several useful hits. We then conducted homology modeling of T. cruzi PDEC and identified other compounds as potential inhibitors through virtual screening. Testing of these compounds against amastigote growth and recombinant TcrPDEC activity resulted in several potent inhibitors. The most-potent inhibitors were found to increase the cellular concentration of cAMP. Preincubation of cells in the presence of one of these compounds stimulated volume recovery after hyposmotic stress, in agreement with their TcrPDEC inhibitory activity in vitro, providing chemical validation of this target. The compounds found could be useful tools in the study of osmoregulation in T. cruzi. In addition, their further optimization could result in the development of new drugs against Chagas' disease and other trypanosomiases.
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Chen W, Huang YJ, Gundala SR, Yang H, Li M, Tai PC, Wang B. The first low microM SecA inhibitors. Bioorg Med Chem 2010; 18:1617-25. [PMID: 20096592 DOI: 10.1016/j.bmc.2009.12.074] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 12/21/2009] [Accepted: 12/31/2009] [Indexed: 01/26/2023]
Abstract
SecA ATPase is a critical member of the Sec family, which is important in the translocation of membrane and secreted polypeptides/proteins in bacteria. Small molecule inhibitors can be very useful research tools as well as leads for future antimicrobial agent development. Based on previous virtual screening work, we optimized the structures of two hit compounds and obtained SecA ATPase inhibitors with IC(50) in the single digit micromolar range. These represent the first low micromolar synthetic inhibitors of bacterial SecA and will be very useful for mechanistic studies.
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Affiliation(s)
- Weixuan Chen
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-4098, USA
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40
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Ni N, Li M, Wang J, Wang B. Inhibitors and antagonists of bacterial quorum sensing. Med Res Rev 2009; 29:65-124. [DOI: 10.1002/med.20145] [Citation(s) in RCA: 158] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Parish CA, de la Cruz M, Smith SK, Zink D, Baxter J, Tucker-Samaras S, Collado J, Platas G, Bills G, Díez MT, Vicente F, Peláez F, Wilson K. Antisense-guided isolation and structure elucidation of pannomycin, a substituted cis-decalin from Geomyces pannorum. JOURNAL OF NATURAL PRODUCTS 2009; 72:59-62. [PMID: 19102658 DOI: 10.1021/np800528a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Antisense-based screening strategies can be used to sensitize a microorganism and selectively detect inhibitors against a particular cellular target of interest. A strain of Staphylococcus aureus that generates an antisense RNA against SecA,a central member of the protein secretion machinery, has been used to screen for novel antibacterials. Possible inhibitors of the SecA ATP-ase were selected with a high-throughput, two-plate agar-based whole cell differential sensitivity screen. After screening a library of over 115 000 natural products extracts with the SecA antisense strain, an extract of Geomyces pannorum was identified as providing increased activity against the sensitized strain as compared with the wild-type control. Bioassay-guided isolation of the active component from this fungal extract provided a new cis-decalin secondary metabolite, which we have named pannomycin.
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Affiliation(s)
- Craig A Parish
- Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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Li M, Ni N, Chou HT, Lu CD, Tai PC, Wang B. Structure-based discovery and experimental verification of novel AI-2 quorum sensing inhibitors against Vibrio harveyi. ChemMedChem 2008; 3:1242-9. [PMID: 18537200 DOI: 10.1002/cmdc.200800076] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Quorum sensing has been implicated in the control of pathologically relevant bacterial behavior such as secretion of virulence factors, biofilm formation, sporulation, and swarming motility. The AI-2 quorum sensing pathway is found in both gram-positive and gram-negative bacteria. Therefore, antagonizing AI-2 quorum sensing is a possible approach to modifying bacterial behaviour. However, efforts in developing inhibitors of AI-2-mediated quorum sensing are especially lacking. High-throughput virtual screening using the V. harveyi LuxP crystal structure identified two compounds that were found to antagonize AI-2-mediated quorum sensing in V. harveyi without cytotoxicity. The sulfone functionality of these inhibitors was identified as critical to their ability to mimic the natural ligand in their interactions with Arg 215 and Arg 310 of the active site.
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Affiliation(s)
- Minyong Li
- Department of Chemistry and Center for Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30302-4098, USA
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Tsai KC, Wang SH, Hsiao NW, Li M, Wang B. The effect of different electrostatic potentials on docking accuracy: a case study using DOCK5.4. Bioorg Med Chem Lett 2008; 18:3509-12. [PMID: 18502122 DOI: 10.1016/j.bmcl.2008.05.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 05/06/2008] [Accepted: 05/07/2008] [Indexed: 11/19/2022]
Abstract
As a commonly used structure-based approach for virtual screening, molecular design and lead optimization, molecular docking can search the preferred orientation and conformation of a ligand for its optimal binding to a receptor or enzyme active site. In doing so, selecting an appropriate method to calculate the electrostatic potentials is critical. In the current report, nine different semi-empirical and empirical methods, including AM1, AM1-BCC, Del-Re, MMFF, Gasteiger, Hückel, Gasteiger-Hückel, Pullman and formal charges were investigated for their performance on the prediction of docking poses using the DOCK5.4 program. The results demonstrated that the AM1-BCC charges had the highest success rate.
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Affiliation(s)
- Keng-Chang Tsai
- The Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115, Taiwan
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