1
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Gao Y, Xie R, Chen Y, Yang B, Wang M, Hua L, Wang X, Wang W, Wang N, Ge H, Ma J. Structural basis for substrate recognition by a S-adenosylhomocysteine hydrolase Lpg2021 from Legionella pneumophila. Int J Biol Macromol 2024; 270:132289. [PMID: 38735607 DOI: 10.1016/j.ijbiomac.2024.132289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 04/24/2024] [Accepted: 05/09/2024] [Indexed: 05/14/2024]
Abstract
S-Adenosyl-l-homocysteine hydrolase (SAHH) is a crucial enzyme that governs S-adenosyl methionine (SAM)-dependent methylation reactions within cells and regulates the intracellular concentration of SAH. Legionella pneumophila, the causative pathogen of Legionnaires' disease, encodes Lpg2021, which is the first identified dimeric SAHH in bacteria and is a promising target for drug development. Here, we report the structure of Lpg2021 in its ligand-free state and in complexes with adenine (ADE), adenosine (ADO), and 3-Deazaneplanocin A (DZNep). X-ray crystallography, isothermal titration calorimetry (ITC), and molecular docking were used to elucidate the binding mechanisms of Lpg2021 to its substrates and inhibitors. Virtual screening was performed to identify potential Lpg2021 inhibitors. This study contributes a novel perspective to the understanding of SAHH evolution and establishes a structural framework for designing specific inhibitors targeting pathogenic Legionella pneumophila SAHH.
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Affiliation(s)
- Yongshan Gao
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China; School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China
| | - Rao Xie
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Yanan Chen
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Beibei Yang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Min Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Lan Hua
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Xu Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Weiqiang Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China
| | - Na Wang
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
| | - Honghua Ge
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
| | - Jinming Ma
- Institute of Health Sciences and Technology, Institutes of Material Science and Information Technology, Anhui University, Hefei 230601, China.
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2
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Derry A, Altman RB. Explainable protein function annotation using local structure embeddings. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.13.562298. [PMID: 37905033 PMCID: PMC10614799 DOI: 10.1101/2023.10.13.562298] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
The rapid expansion of protein sequence and structure databases has resulted in a significant number of proteins with ambiguous or unknown function. While advances in machine learning techniques hold great potential to fill this annotation gap, current methods for function prediction are unable to associate global function reliably to the specific residues responsible for that function. We address this issue by introducing PARSE (Protein Annotation by Residue-Specific Enrichment), a knowledge-based method which combines pre-trained embeddings of local structural environments with traditional statistical techniques to identify enriched functions with residue-level explainability. For the task of predicting the catalytic function of enzymes, PARSE achieves comparable or superior global performance to state-of-the-art machine learning methods (F1 score > 85%) while simultaneously annotating the specific residues involved in each function with much greater precision. Since it does not require supervised training, our method can make one-shot predictions for very rare functions and is not limited to a particular type of functional label (e.g. Enzyme Commission numbers or Gene Ontology codes). Finally, we leverage the AlphaFold Structure Database to perform functional annotation at a proteome scale. By applying PARSE to the dark proteome-predicted structures which cannot be classified into known structural families-we predict several novel bacterial metalloproteases. Each of these proteins shares a strongly conserved catalytic site despite highly divergent sequences and global folds, illustrating the value of local structure representations for new function discovery.
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Affiliation(s)
- Alexander Derry
- Department of Biomedical Data Science, Stanford University, Stanford, CA
| | - Russ B Altman
- Department of Biomedical Data Science, Stanford University, Stanford, CA
- Departments of Bioengineering, Genetics, and Medicine, Stanford University, Stanford, CA
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3
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Wang J, Song Y, Huang Z, Lin W, Yu G, Xiong Y, Jiang G, Tan Y, Wang J, Liao X. Coupling a Virulence-Targeting Moiety with Ru-Based AMP Mimics Efficiently Improved Its Anti-Infective Potency and Therapeutic Index. J Med Chem 2023; 66:13304-13318. [PMID: 37704628 DOI: 10.1021/acs.jmedchem.3c01282] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
The surge of antibiotic resistance in Staphylococcus aureus calls for novel drugs that attack new targets. Developing antimicrobial peptides (AMPs) or antivirulence agents (AvAs) is a promising strategy to tackle this challenge. However, AMPs, which kill bacteria by disrupting cell membranes, suffer from low stability and high synthesis cost, while AvAs, which inhibit toxin secretion, have relatively poor bactericidal activity. Here, to address their respective shortcomings, we combined these two different antibacterial activities on the same molecular scaffold and developed a Ru-based metalloantibiotic, termed Ru1. Notably, Ru1 exerted remarkable bactericidal activity (MICS = 460 nM) and attenuated bacterial virulence as well. Mechanistic studies demonstrated that Ru1 had two independent targets: CcpA and bacterial membrane integrity. Based on its dual mechanism of action, Ru1 effectively overcame S. aureus resistance and showed high efficacy in a mouse infection model against S. aureus. This study provides a promising approach to confronting bacterial infections.
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Affiliation(s)
- Jing Wang
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Yun Song
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Ziying Huang
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Wenjing Lin
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Guangying Yu
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Yanshi Xiong
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Guijuan Jiang
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Yanhui Tan
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
| | - Jintao Wang
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
| | - Xiangwen Liao
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China
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4
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Sundar S, Piramanayagam S, Natarajan J. A comprehensive review on human disease-causing bacterial proteases and their impeding agents. Arch Microbiol 2023; 205:276. [PMID: 37414902 DOI: 10.1007/s00203-023-03618-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/20/2023] [Accepted: 06/24/2023] [Indexed: 07/08/2023]
Abstract
Proteases are enzymes that catalyze the amide bond dissociation in polypeptide and protein peptide units. They are categorized into seven families and are responsible for a wide spectrum of human ailments, such as various types of cancers, skin infections, urinary tract infections etc. Specifically, the bacterial proteases cause a huge impact in the disease progression. Extracellular bacterial proteases break down the host defense proteins, while intracellular proteases are essential for pathogens virulence. Due to its involvement in disease pathogenesis and virulence, bacterial proteases are considered to be potential drug targets. Several studies have reported potential bacterial protease inhibitors in both Gram-positive and Gram-negative disease causing pathogens. In this study, we have comprehensively reviewed about the various human disease-causing cysteine, metallo, and serine bacterial proteases as well as their potential inhibitors.
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Affiliation(s)
- Shobana Sundar
- Department of Biotechnology, PSG College of Technology, Coimbatore, India
| | | | - Jeyakumar Natarajan
- Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, Tamil Nadu, India.
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5
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Li M, Chen S, Wang Y, Zhang S, Song D, Tian R, Geng J, Wang L. Label-free high-precise nanopore detection of endopeptidase activity of anthrax lethal factor regulated by diverse conditions. Biosens Bioelectron 2023; 219:114800. [PMID: 36274430 DOI: 10.1016/j.bios.2022.114800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/24/2022] [Accepted: 10/08/2022] [Indexed: 11/19/2022]
Abstract
Endopeptidase activity of anthrax lethal factor (aLF) prevents the destroy of anthracis spore intracellularly by host macrophages, meanwhile disables the signaling pathways extracellularly that leads to host lethality. Hence, inhibitory of this activity is expected to be an alternative option to cure anthrax infection. Herein, we fabricated a nanopore platform via transmembrane pore construction in vitro, which allows precise mimics, monitoring of intercellular proteinic transport and enables the quantitative detection of aLF endopeptidase activity towards MAPKK signaling protein at single molecule level. Next, we inhibited the aLF activity via screening approaches of protein-metal ion acquisition and other condition controlment (proton/hydroxide strength, adapted temperature, ionizing irradiation), which were identified by nanopore electrokinetic study. Upon the results, we found that Ca2+, Mg2+, Mn2+, Ni2+ collaborating with Zn2+ promote aLF activity efficiently. In contrary, Cd2+, Co2+, Cu2+ have great inhibitory effect. Result further revealed that, the speed of aLF endopeptidase activity with different ions functions as the nanopore signal frequency in linear manner, which enables evident distinction of those divalent ions using this proteinase assay. We also found the higher strength of the proton or hydroxide, the higher the inhibitory to aLF activity. Besides, adapted temperature and γ-ray also play integral roles in inhibiting this activity. Our results lay experimental basis for accurate detection of aLF activity, meanwhile provide new direction to screening novel stimuli-responsive inhibitors specific to aLF.
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Affiliation(s)
- Minghan Li
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China; Department of Laboratory Medicine, State Key Laboratory of Biotherapy, Med-X Center for Manufacturing, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Shanchuan Chen
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China
| | - Yunjiao Wang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China
| | - Shaoxia Zhang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China; School of Optoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
| | - Dandan Song
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China; School of Optoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing, 400065, China
| | - Rong Tian
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China
| | - Jia Geng
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy, Med-X Center for Manufacturing, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China
| | - Liang Wang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China.
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6
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Research Progress on Small Molecular Inhibitors of the Type 3 Secretion System. Molecules 2022; 27:molecules27238348. [PMID: 36500441 PMCID: PMC9740592 DOI: 10.3390/molecules27238348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
The overuse of antibiotics has led to severe bacterial drug resistance. Blocking pathogen virulence devices is a highly effective approach to combating bacterial resistance worldwide. Type three secretion systems (T3SSs) are significant virulence factors in Gram-negative pathogens. Inhibition of these systems can effectively weaken infection whilst having no significant effect on bacterial growth. Therefore, T3SS inhibitors may be a powerful weapon against resistance in Gram-negative bacteria, and there has been increasing interest in the research and development of T3SS inhibitors. This review outlines several reported small-molecule inhibitors of the T3SS, covering those of synthetic and natural origin, including their sources, structures, and mechanisms of action.
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7
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Hou R, He Y, Yan G, Hou S, Xie Z, Liao C. Zinc enzymes in medicinal chemistry. Eur J Med Chem 2021; 226:113877. [PMID: 34624823 DOI: 10.1016/j.ejmech.2021.113877] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/27/2021] [Accepted: 09/17/2021] [Indexed: 12/31/2022]
Abstract
In humans, more than three hundred diverse enzymes that require zinc as an essential cofactor have been identified. These zinc enzymes have demonstrated different and important physiological functions and some of them have been considered as valuable therapeutic targets for drug discovery. Indeed, many drugs targeting a few zinc enzymes have been marketed to treat a variety of diseases. This review discusses drug discovery and drug development based on a dozen of zinc enzymes, including their biological functions and pathogenic roles, their best in class inhibitors (and clinical trial data when available), coordination and binding modes of representative inhibitors, and their implications for further drug design. The opportunities and challenges in developing zinc enzyme inhibitors for the treatment of human disorders are highlighted, too.
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Affiliation(s)
- Rui Hou
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Yan He
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Guangwei Yan
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Shuzeng Hou
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China
| | - Zhouling Xie
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.
| | - Chenzhong Liao
- Department of Pharmaceutical Sciences and Engineering, School of Food and Biological Engineering, Hefei University of Technology, Hefei, 230009, China.
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8
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Pollock J, Low AS, McHugh RE, Muwonge A, Stevens MP, Corbishley A, Gally DL. Alternatives to antibiotics in a One Health context and the role genomics can play in reducing antimicrobial use. Clin Microbiol Infect 2020; 26:1617-1621. [PMID: 32220638 DOI: 10.1016/j.cmi.2020.02.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/19/2020] [Accepted: 02/22/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND This review follows on from the International Conference on One Health Antimicrobial Resistance (ICOHAR 2019), where strategies to improve the fundamental understanding and management of antimicrobial resistance at the interface between humans, animals and the environment were discussed. OBJECTIVE This review identifies alternatives to antimicrobials in a One Health context, noting how advances in genomic technologies are assisting their development and enabling more targeted use of antimicrobials. SOURCES Key articles on the use of microbiota modulation, livestock breeding and gene editing, vaccination, antivirulence strategies and bacteriophage therapy are discussed. CONTENT Antimicrobials are central for disease control, but reducing their use is paramount as a result of the rise of transmissible antimicrobial resistance. This review discusses antimicrobial alternatives in the context of improved understanding of fundamental host-pathogen and microbiota interactions using genomic tools. IMPLICATIONS Host and microbial genomics and other novel technologies play an important role in devising disease control strategies for healthier animals and humans that in turn reduce our reliance on antimicrobials.
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Affiliation(s)
- J Pollock
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - A S Low
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - R E McHugh
- Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, Scotland, UK; Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK
| | - A Muwonge
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - M P Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - A Corbishley
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK
| | - D L Gally
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, Edinburgh, UK.
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9
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Wang J, Yang D, Shen X, Wang J, Liu X, Lin J, Zhong J, Zhao Y, Qi Z. BPTES inhibits anthrax lethal toxin-induced inflammatory response. Int Immunopharmacol 2020; 85:106664. [PMID: 32521490 DOI: 10.1016/j.intimp.2020.106664] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 11/17/2022]
Abstract
Bacillus anthracis is a lethal agent of anthrax disease and the toxins are required in anthrax pathogenesis. The anthrax lethal toxin can trigger NLRP1b inflammasome activation and pyroptosis. Although the underlying mechanism is well understood, the medications targeting the NLRP1b inflammasome are not available in the clinic. Herein, we describe that BPTES, a known Glutaminase (GLS) inhibitor, is an effective NLRP1b inflammasome inhibitor. BPTES could effectively and specifically suppress NLRP1b inflammasome activation in macrophages but have no effects on NLRP3, NLRC4 and AIM2 inflammasome activation. Mechanistically, BPTES alleviated the UBR2 mediated proteasomal degradation pathway of the NLRP1b N terminus, thus blocking the release of the CARD domain for subsequent caspase-1 processing. Furthermore, BPTES could prevent disease progression in mice challenged with the anthrax lethal toxin. Taken together, our studies indicate that BPTES can be a promising pharmacological inhibitor to treat anthrax lethal toxin-related inflammatory diseases.
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Affiliation(s)
- Jinling Wang
- Department of Emergency, Zhongshan Hospital of Xiamen University, Xiamen 361005, China
| | - Daowei Yang
- Department of Emergency, Zhongshan Hospital of Xiamen University, Xiamen 361005, China.
| | - Xizi Shen
- Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Junsheng Wang
- Department of Emergency, Zhongshan Hospital of Xiamen University, Xiamen 361005, China
| | - Xiaomei Liu
- Department of Emergency, Zhongshan Hospital of Xiamen University, Xiamen 361005, China
| | - Jinzhou Lin
- Department of Emergency, Zhongshan Hospital of Xiamen University, Xiamen 361005, China
| | - Jiaying Zhong
- Faculty of Medicine, Xiamen University, Xiamen, China
| | - Yilin Zhao
- Department of Oncology and Vascular Interventional Radiology, Zhongshan Hospital of Xiamen University, Xiamen, China
| | - Zhongquan Qi
- School of Medicine, Guangxi University, Nanning 530004, China.
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10
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Potential Therapeutic Targeting of Coronavirus Spike Glycoprotein Priming. Molecules 2020; 25:molecules25102424. [PMID: 32455942 PMCID: PMC7287953 DOI: 10.3390/molecules25102424] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022] Open
Abstract
Processing of certain viral proteins and bacterial toxins by host serine proteases is a frequent and critical step in virulence. The coronavirus spike glycoprotein contains three (S1, S2, and S2′) cleavage sites that are processed by human host proteases. The exact nature of these cleavage sites, and their respective processing proteases, can determine whether the virus can cross species and the level of pathogenicity. Recent comparisons of the genomes of the highly pathogenic SARS-CoV2 and MERS-CoV, with less pathogenic strains (e.g., Bat-RaTG13, the bat homologue of SARS-CoV2) identified possible mutations in the receptor binding domain and in the S1 and S2′ cleavage sites of their spike glycoprotein. However, there remains some confusion on the relative roles of the possible serine proteases involved for priming. Using anthrax toxin as a model system, we show that in vivo inhibition of priming by pan-active serine protease inhibitors can be effective at suppressing toxicity. Hence, our studies should encourage further efforts in developing either pan-serine protease inhibitors or inhibitor cocktails to target SARS-CoV2 and potentially ward off future pandemics that could develop because of additional mutations in the S-protein priming sequence in coronaviruses.
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11
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Jack S, Madhivanan K, Ramadesikan S, Subramanian S, Edwards DF, Elzey BD, Dhawan D, McCluskey A, Kischuk EM, Loftis AR, Truex N, Santos M, Lu M, Rabideau A, Pentelute B, Collier J, Kaimakliotis H, Koch M, Ratliff TL, Knapp DW, Aguilar RC. A novel, safe, fast and efficient treatment for Her2-positive and negative bladder cancer utilizing an EGF-anthrax toxin chimera. Int J Cancer 2019; 146:449-460. [PMID: 31584195 DOI: 10.1002/ijc.32719] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/10/2019] [Accepted: 09/11/2019] [Indexed: 12/20/2022]
Abstract
Bladder cancer is the sixth most common cancer in the United States, and it exhibits an alarming 70% recurrence rate. Thus, the development of more efficient antibladder cancer approaches is a high priority. Accordingly, this work provides the basis for a transformative anticancer strategy that takes advantage of the unique characteristics of the bladder. Unlike mucin-shielded normal bladder cells, cancer cells are exposed to the bladder lumen and overexpress EGFR. Therefore, we used an EGF-conjugated anthrax toxin that after targeting EGFR was internalized and triggered apoptosis in exposed bladder cancer cells. This unique agent presented advantages over other EGF-based technologies and other toxin-derivatives. In contrast to known agents, this EGF-toxin conjugate promoted its own uptake via receptor microclustering even in the presence of Her2 and induced cell death with a LC50 < 1 nM. Furthermore, our data showed that exposures as short as ≈3 min were enough to commit human (T24), mouse (MB49) and canine (primary) bladder cancer cells to apoptosis. Exposure of tumor-free mice and dogs with the agent resulted in no toxicity. In addition, the EGF-toxin was able to eliminate cells from human patient tumor samples. Importantly, the administration of EGF-toxin to dogs with spontaneous bladder cancer, who had failed or were not eligible for other therapies, resulted in ~30% average tumor reduction after one treatment cycle. Because of its in vitro and in vivo high efficiency, fast action (reducing treatment time from hours to minutes) and safety, we propose that this EGF-anthrax toxin conjugate provides the basis for new, transformative approaches against bladder cancer.
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Affiliation(s)
- Sherwin Jack
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Kayalvizhi Madhivanan
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Swetha Ramadesikan
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Sneha Subramanian
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Daniel F Edwards
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
| | - Bennett D Elzey
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Comparative Pathobiology, Purdue University, West Lafayette, IN.,Department of Urology, Indiana University School of Medicine, Indianapolis, IN
| | - Deepika Dhawan
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN
| | | | - Erin M Kischuk
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Comparative Pathobiology, Purdue University, West Lafayette, IN
| | - Alexander R Loftis
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA
| | - Nicholas Truex
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA
| | - Michael Santos
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA
| | - Mike Lu
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA
| | - Amy Rabideau
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA
| | - Bradley Pentelute
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA.,Koch Institute MIT, Cambridge, MA.,Broad Institute of Harvard and MIT, Cambridge, MA.,Center for Environmental Health Sciences MIT, Cambridge, MA
| | - John Collier
- Department of Microbiology, Harvard Medical School, Boston, MA
| | | | - Michael Koch
- Department of Urology, Indiana University School of Medicine, Indianapolis, IN
| | - Timothy L Ratliff
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Comparative Pathobiology, Purdue University, West Lafayette, IN
| | - Deborah W Knapp
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN
| | - Ruben C Aguilar
- Purdue University Center for Cancer Research, West Lafayette, IN.,Department of Biological Sciences, Purdue University, West Lafayette, IN
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12
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Omersa N, Podobnik M, Anderluh G. Inhibition of Pore-Forming Proteins. Toxins (Basel) 2019; 11:E545. [PMID: 31546810 PMCID: PMC6784129 DOI: 10.3390/toxins11090545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
Perforation of cellular membranes by pore-forming proteins can affect cell physiology, tissue integrity, or immune response. Since many pore-forming proteins are toxins or highly potent virulence factors, they represent an attractive target for the development of molecules that neutralize their actions with high efficacy. There has been an assortment of inhibitors developed to specifically obstruct the activity of pore-forming proteins, in addition to vaccination and antibiotics that serve as a plausible treatment for the majority of diseases caused by bacterial infections. Here we review a wide range of potential inhibitors that can specifically and effectively block the activity of pore-forming proteins, from small molecules to more specific macromolecular systems, such as synthetic nanoparticles, antibodies, antibody mimetics, polyvalent inhibitors, and dominant negative mutants. We discuss their mechanism of inhibition, as well as advantages and disadvantages.
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Affiliation(s)
- Neža Omersa
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Marjetka Podobnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
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13
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Chen AY, Adamek RN, Dick BL, Credille CV, Morrison CN, Cohen SM. Targeting Metalloenzymes for Therapeutic Intervention. Chem Rev 2019; 119:1323-1455. [PMID: 30192523 PMCID: PMC6405328 DOI: 10.1021/acs.chemrev.8b00201] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metalloenzymes are central to a wide range of essential biological activities, including nucleic acid modification, protein degradation, and many others. The role of metalloenzymes in these processes also makes them central for the progression of many diseases and, as such, makes metalloenzymes attractive targets for therapeutic intervention. Increasing awareness of the role metalloenzymes play in disease and their importance as a class of targets has amplified interest in the development of new strategies to develop inhibitors and ultimately useful drugs. In this Review, we provide a broad overview of several drug discovery efforts focused on metalloenzymes and attempt to map out the current landscape of high-value metalloenzyme targets.
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Affiliation(s)
- Allie Y Chen
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Rebecca N Adamek
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Benjamin L Dick
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Cy V Credille
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Christine N Morrison
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Seth M Cohen
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
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14
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Lahousse M, Park HC, Lee SC, Ha NR, Jung IP, Schlesinger SR, Shackelford K, Yoon MY, Kim SK. Inhibition of anthrax lethal factor by ssDNA aptamers. Arch Biochem Biophys 2018; 646:16-23. [PMID: 29580944 DOI: 10.1016/j.abb.2018.03.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/04/2018] [Accepted: 03/22/2018] [Indexed: 01/12/2023]
Abstract
Anthrax is caused by Bacillus anthracis, a bacterium that is able to secrete the toxins protective antigen, edema factor and lethal factor. Due to the high level of secretion from the bacteria and its severe virulence, lethal factor (LF) has been sought as a biomarker for detecting bacterial infection and as an effective target to neutralize toxicity. In this study, we found three aptamers, and binding affinity was determined by fluorescently labeled aptamers. One of the aptamers exhibited high affinity, with a Kd value of 11.0 ± 2.7 nM, along with low cross reactivity relative to bovine serum albumin and protective antigen. The therapeutic functionality of the aptamer was examined by assessing the inhibition of LF protease activity against a mitogen-activated protein kinase kinase. The aptamer appears to be an effective inhibitor of LF with an IC50 value of 15 ± 1.5 μM and approximately 85% cell viability, suggesting that this aptamer provides a potential clue for not only development of a sensitive diagnostic device of B. anthracis infection but also the design of novel inhibitors of LF.
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Affiliation(s)
- Mieke Lahousse
- The Institute of Biomedical Studies, and the Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798-7348, USA
| | - Hae-Chul Park
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sang-Choon Lee
- Department of Chemistry, Georgia State University, Atlanta, GA 30303, USA
| | - Na-Reum Ha
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - In-Pil Jung
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sara R Schlesinger
- The Institute of Biomedical Studies, and the Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798-7348, USA
| | - Kaylin Shackelford
- Department of Natural Sciences, Northeastern State University, Tahlequah, OK 74464, USA
| | - Moon-Young Yoon
- Department of Chemistry, Hanyang University, Seoul, 133-791, Republic of Korea
| | - Sung-Kun Kim
- Department of Natural Sciences, Northeastern State University, Tahlequah, OK 74464, USA.
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15
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Young CJ, Richard K, Beruar A, Lo SY, Siemann S. An investigation of the pH dependence of copper-substituted anthrax lethal factor and its mechanistic implications. J Inorg Biochem 2018; 182:1-8. [PMID: 29407865 DOI: 10.1016/j.jinorgbio.2018.01.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/18/2017] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
Abstract
Anthrax lethal factor (LF) is a zinc-dependent endopeptidase involved in the cleavage of proteins critical to the maintenance of host signaling pathways during anthrax infections. Although zinc is typically regarded as the native metal ion in vivo, LF is highly tolerant to metal substitution, with its replacement by copper yielding an enzyme (CuLF) 4.5-fold more active than the native zinc protein (at pH 7). The current study demonstrates that by careful choice of the buffer, ionic strength, pH and substrate, the activity ratio of CuLF and native LF can be increased to >40-fold. Using a fluorogenic LF substrate, such optimized assay conditions can be exploited to detect LF concentrations as low as 2 pM. In contrast to the zinc form, CuLF was found to be inhibited by bromide and iodide ions, to be resistant to metal loss under acidic conditions, and to display a sharp pH dependence with significantly shifted alkaline limb towards more acidic conditions. The alkaline limb in the enzyme's pH profile is suggested to originate from changes in the protonation state of the metal-bound water molecule which serves as the nucleophile in the catalytic mechanism. Based on these observations and studies on other zinc proteases, a minimal mechanism for LF is proposed.
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Affiliation(s)
- Calvin J Young
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Kaitlin Richard
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Ananya Beruar
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Suet Y Lo
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada
| | - Stefan Siemann
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada.
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16
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Turk BE. Exceptionally Selective Substrate Targeting by the Metalloprotease Anthrax Lethal Factor. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1111:189-203. [PMID: 30267305 DOI: 10.1007/5584_2018_273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The zinc-dependent metalloprotease anthrax lethal factor (LF) is the enzymatic component of a toxin thought to have a major role in Bacillus anthracis infections. Like many bacterial toxins, LF is a secreted protein that functions within host cells. LF is a highly selective protease that cleaves a limited number of substrates in a site-specific manner, thereby impacting host signal transduction pathways. The major substrates of LF are mitogen-activated protein kinase kinases (MKKs), which lie in the middle of three-component phosphorylation cascades mediating numerous functions in a variety of cells and tissues. How LF targets its limited substrate repertoire has been an active area of investigation. LF recognizes a specific sequence motif surrounding the scissile bonds of substrate proteins. X-ray crystallography of the protease in complex with peptide substrates has revealed the structural basis of selectivity for the LF cleavage site motif. In addition to having interactions proximal to the cleavage site, LF binds directly to a more distal region in its substrates through a so-called exosite interaction. This exosite has been mapped to a surface within a non-catalytic domain of LF with previously unknown function. A putative LF-binding site has likewise been identified on the catalytic domains of MKKs. Here we review our current state of understanding of LF-substrate interactions and discuss the implications for the design and discovery of inhibitors that may have utility as anthrax therapeutics.
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Affiliation(s)
- Benjamin E Turk
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA.
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17
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Magnolol protects channel catfish from Aeromonas hydrophila infection via inhibiting the expression of aerolysin. Vet Microbiol 2017; 211:119-123. [PMID: 29102106 DOI: 10.1016/j.vetmic.2017.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 10/09/2017] [Accepted: 10/09/2017] [Indexed: 01/20/2023]
Abstract
Aeromonas hydrophila is a common zoonotic pathogen which can cause several infections both in human and animals, particular aquatic animals. Antibiotics have been widely used in the treatment of A. hydrophila infections, however, the development of resistance has limited the treatment for these infections. There is an urgent need for novel agents and strategies against these infections. Aerolysin, a pore-forming toxin secreted by most pathogenic A. hydrophila, is known to contribute to the pathogenesis of A. hydrophila infections. Therefore, aerolysin has been identified as a potential target for drug discovery. In this paper, we found that magnolol, a natural compound without anti -A. hydrophila activity, could significantly inhibit the hemolytic activity of A. hydrophila culture supernatants by inhibiting the transcription of the aerolysin encoding gene aerA at low concentrations. Furthermore, the survival assay showed that magnolol could significantly reduce the mortality induced by A. hydrophila infection in channel catfish (Ictalurus punctatus). Taken together, these findings provide a potent agent against A. hydrophila infections.
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18
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Munguia J, Nizet V. Pharmacological Targeting of the Host-Pathogen Interaction: Alternatives to Classical Antibiotics to Combat Drug-Resistant Superbugs. Trends Pharmacol Sci 2017; 38:473-488. [PMID: 28283200 DOI: 10.1016/j.tips.2017.02.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 01/17/2023]
Abstract
The rise of multidrug-resistant pathogens and the dearth of new antibiotic development place an existential strain on successful infectious disease therapy. Breakthrough strategies that go beyond classical antibiotic mechanisms are needed to combat this looming public health catastrophe. Reconceptualizing antibiotic therapy in the richer context of the host-pathogen interaction is required for innovative solutions. By defining specific virulence factors, the essence of a pathogen, and pharmacologically neutralizing their activities, one can block disease progression and sensitize microbes to immune clearance. Likewise, host-directed strategies to boost phagocyte bactericidal activity, enhance leukocyte recruitment, or reverse pathogen-induced immunosuppression seek to replicate the success of cancer immunotherapy in the field of infectious diseases. The answer to the threat of multidrug-resistant pathogens lies 'outside the box' of current antibiotic paradigms.
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Affiliation(s)
- Jason Munguia
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, Division of Host-Microbe Systems and Therapeutics, University of California San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, CA 92093, USA; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093, USA; Rady Children's Hospital, San Diego, CA 92123, USA.
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19
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Affiliation(s)
- Megan Garland
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Sebastian Loscher
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
| | - Matthew Bogyo
- Cancer
Biology Program, ‡Department of Pathology, §Department of Microbiology and Immunology, and ∥Department of
Chemical and Systems Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305, United States
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20
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Goldberg AB, Cho E, Miller CJ, Lou HJ, Turk BE. Identification of a Substrate-selective Exosite within the Metalloproteinase Anthrax Lethal Factor. J Biol Chem 2016; 292:814-825. [PMID: 27909054 DOI: 10.1074/jbc.m116.761734] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 11/23/2016] [Indexed: 01/02/2023] Open
Abstract
The metalloproteinase anthrax lethal factor (LF) is secreted by Bacillus anthracis to promote disease virulence through disruption of host signaling pathways. LF is a highly specific protease, exclusively cleaving mitogen-activated protein kinase kinases (MKKs) and rodent NLRP1B (NACHT leucine-rich repeat and pyrin domain-containing protein 1B). How LF achieves such restricted substrate specificity is not understood. Previous studies have suggested the existence of an exosite interaction between LF and MKKs that promotes cleavage efficiency and specificity. Through a combination of in silico prediction and site-directed mutagenesis, we have mapped an exosite to a non-catalytic region of LF. Mutations within this site selectively impair proteolysis of full-length MKKs yet have no impact on cleavage of short peptide substrates. Although this region appears important for cleaving all LF protein substrates, we found that mutation of specific residues within the exosite differentially affects MKK and NLRP1B cleavage in vitro and in cultured cells. One residue in particular, Trp-271, is essential for cleavage of MKK3, MKK4, and MKK6 but dispensable for targeting of MEK1, MEK2, and NLRP1B. Analysis of chimeric substrates suggests that this residue interacts with the MKK catalytic domain. We found that LF-W271A blocked ERK phosphorylation and growth in a melanoma cell line, suggesting that it may provide a highly selective inhibitor of MEK1/2 for use as a cancer therapeutic. These findings provide insight into how a bacterial toxin functions to specifically impair host signaling pathways and suggest a general strategy for mapping protease exosite interactions.
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Affiliation(s)
- Allison B Goldberg
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Eunice Cho
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Chad J Miller
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Hua Jane Lou
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Benjamin E Turk
- From the Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520
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21
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Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med 2016; 8:39. [PMID: 27074706 PMCID: PMC4831151 DOI: 10.1186/s13073-016-0294-z] [Citation(s) in RCA: 521] [Impact Index Per Article: 65.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The widespread use of antibiotics in the past 80 years has saved millions of human lives, facilitated technological progress and killed incalculable numbers of microbes, both pathogenic and commensal. Human-associated microbes perform an array of important functions, and we are now just beginning to understand the ways in which antibiotics have reshaped their ecology and the functional consequences of these changes. Mounting evidence shows that antibiotics influence the function of the immune system, our ability to resist infection, and our capacity for processing food. Therefore, it is now more important than ever to revisit how we use antibiotics. This review summarizes current research on the short-term and long-term consequences of antibiotic use on the human microbiome, from early life to adulthood, and its effect on diseases such as malnutrition, obesity, diabetes, and Clostridium difficile infection. Motivated by the consequences of inappropriate antibiotic use, we explore recent progress in the development of antivirulence approaches for resisting infection while minimizing resistance to therapy. We close the article by discussing probiotics and fecal microbiota transplants, which promise to restore the microbiota after damage of the microbiome. Together, the results of studies in this field emphasize the importance of developing a mechanistic understanding of gut ecology to enable the development of new therapeutic strategies and to rationally limit the use of antibiotic compounds.
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Affiliation(s)
- Amy Langdon
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA
- Clinical Research Training Center, Washington University School of Medicine, Campus Box 8051, 660 South Euclid Avenue, St. Louis, MO, 63110-1093, USA
| | - Nathan Crook
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA
- Department of Pathology & Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Ave, St. Louis, MO, 63110, USA
| | - Gautam Dantas
- Center for Genome Sciences, Washington University School of Medicine, Campus Box 8510, 4515 McKinley Research Building, St. Louis, MO, 63108, USA.
- Department of Pathology & Immunology, Washington University School of Medicine, Campus Box 8118, 660 South Euclid Ave, St. Louis, MO, 63110, USA.
- Department of Biomedical Engineering, Washington University in Saint Louis, Campus Box 1097, 1 Brookings Drive, Saint Louis, MO, 63130, USA.
- Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8230, 660 S. Euclid Ave, St. Louis, MO, 63110, USA.
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22
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Ambrose EA. Botulinum Neurotoxin, Tetanus Toxin, and Anthrax Lethal Factor Countermeasures. TOPICS IN MEDICINAL CHEMISTRY 2016. [DOI: 10.1007/7355_2016_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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23
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Maize KM, Kurbanov EK, Johnson RL, Amin EA, Finzel BC. Ligand-induced expansion of the S1' site in the anthrax toxin lethal factor. FEBS Lett 2015; 589:3836-41. [PMID: 26578066 DOI: 10.1016/j.febslet.2015.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 12/31/2022]
Abstract
The Bacillus anthracis lethal factor (LF) is one component of a tripartite exotoxin partly responsible for persistent anthrax cytotoxicity after initial bacterial infection. Inhibitors of the zinc metalloproteinase have been investigated as potential therapeutic agents, but LF is a challenging target because inhibitors lack sufficient selectivity or possess poor pharmaceutical properties. These structural studies reveal an alternate conformation of the enzyme, induced upon binding of specific inhibitors, that opens a previously unobserved deep pocket termed S1'(∗) which might afford new opportunities to design selective inhibitors that target this subsite.
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Affiliation(s)
- Kimberly M Maize
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St SE, 8-101 Weaver-Densford Hall, Minneapolis, MN 55455, United States
| | - Elbek K Kurbanov
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St SE, 8-101 Weaver-Densford Hall, Minneapolis, MN 55455, United States
| | - Rodney L Johnson
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St SE, 8-101 Weaver-Densford Hall, Minneapolis, MN 55455, United States
| | - Elizabeth Ambrose Amin
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St SE, 8-101 Weaver-Densford Hall, Minneapolis, MN 55455, United States
| | - Barry C Finzel
- Department of Medicinal Chemistry, University of Minnesota, 308 Harvard St SE, 8-101 Weaver-Densford Hall, Minneapolis, MN 55455, United States.
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24
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Greaney AJ, Leppla SH, Moayeri M. Bacterial Exotoxins and the Inflammasome. Front Immunol 2015; 6:570. [PMID: 26617605 PMCID: PMC4639612 DOI: 10.3389/fimmu.2015.00570] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/26/2015] [Indexed: 11/24/2022] Open
Abstract
The inflammasomes are intracellular protein complexes that play an important role in innate immune sensing. Activation of inflammasomes leads to activation of caspase-1 and maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. In certain myeloid cells, this activation can also lead to an inflammatory cell death (pyroptosis). Inflammasome sensor proteins have evolved to detect a range of microbial ligands and bacterial exotoxins either through direct interaction or by detection of host cell changes elicited by these effectors. Bacterial exotoxins activate the inflammasomes through diverse processes, including direct sensor cleavage, modulation of ion fluxes through plasma membrane pore formation, and perturbation of various host cell functions. In this review, we summarize the findings on some of the bacterial exotoxins that activate the inflammasomes.
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Affiliation(s)
- Allison J Greaney
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, MD , USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, MD , USA
| | - Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bethesda, MD , USA
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25
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Kurbanov EK, Chiu TL, Solberg J, Francis S, Maize KM, Fernandez J, Johnson RL, Hawkinson JE, Walters MA, Finzel BC, Amin EA. Probing the S2′ Subsite of the Anthrax Toxin Lethal Factor Using Novel N-Alkylated Hydroxamates. J Med Chem 2015; 58:8723-33. [DOI: 10.1021/acs.jmedchem.5b01446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elbek K. Kurbanov
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Ting-Lan Chiu
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jonathan Solberg
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Subhashree Francis
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Kimberly M. Maize
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jenna Fernandez
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Rodney L. Johnson
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Jon E. Hawkinson
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Michael A. Walters
- Institute
for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Barry C. Finzel
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
| | - Elizabeth Ambrose Amin
- Department
of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414, United States
- Minnesota
Supercomputing Institute for Advanced Computational Research, University of Minnesota, Minneapolis, Minnesota 55455, United States
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26
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Kulshreshtha P, Tiwari A, Priyanka, Joon S, Sinha S, Bhatnagar R. Investigation of a panel of monoclonal antibodies and polyclonal sera against anthrax toxins resulted in identification of an anti-lethal factor antibody with disease-enhancing characteristics. Mol Immunol 2015; 68:185-93. [PMID: 26364143 DOI: 10.1016/j.molimm.2015.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/14/2015] [Accepted: 07/17/2015] [Indexed: 11/27/2022]
Abstract
Hybridomas were created using spleen of mice that were actively immunized with rLFn (recombinant N-terminal domain of lethal factor). Later on, separate group of mice were immunized with rLFn to obtain a polyclonal control for passive immunization studies of monoclonal antibodies. This led to the identification of one cohort of rLFn-immnized mice that harboured disease-enhancing polyclonal antibodies. At the same time, the monoclonal antibodies secreted by all the hybridomas were being tested. Two hybridomas secreted monoclonal antibodies (H10 and H8) that were cross-reactive with EF (edema factor) and LF (lethal factor), while the other two hybridomas secreted LF-specific antibodies (H7 and H11). Single chain variable fragment (LETscFv) was derived from H10 hybridoma. H11 was found to have disease-enhancing property. Combination of H11 with protective monoclonal antibodies (H8 and H10) reduced its disease enhancing nature. This in vitro abrogation of disease-enhancement provides the proof of concept that in polyclonal sera the disease enhancing character of a fraction of antibodies is overshadowed by the protective nature of the rest of the antibodies generated on active immunization.
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Affiliation(s)
- Parul Kulshreshtha
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ashutosh Tiwari
- Present address: Centre for Biodesign, Translational Health Science and Technology Institute, Gurgaon, India
| | - Priyanka
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Shikha Joon
- Structural and Computational Biology Laboratory, Department Of Biotechnology, Netaji Subhas Institute of Technology, New Delhi 110078, India
| | | | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
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27
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Abstract
Anthrax is caused by the spore-forming, gram-positive bacterium Bacillus anthracis. The bacterium's major virulence factors are (a) the anthrax toxins and (b) an antiphagocytic polyglutamic capsule. These are encoded by two large plasmids, the former by pXO1 and the latter by pXO2. The expression of both is controlled by the bicarbonate-responsive transcriptional regulator, AtxA. The anthrax toxins are three polypeptides-protective antigen (PA), lethal factor (LF), and edema factor (EF)-that come together in binary combinations to form lethal toxin and edema toxin. PA binds to cellular receptors to translocate LF (a protease) and EF (an adenylate cyclase) into cells. The toxins alter cell signaling pathways in the host to interfere with innate immune responses in early stages of infection and to induce vascular collapse at late stages. This review focuses on the role of anthrax toxins in pathogenesis. Other virulence determinants, as well as vaccines and therapeutics, are briefly discussed.
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Affiliation(s)
- Mahtab Moayeri
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Catherine Vrentas
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Andrei P Pomerantsev
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
| | - Shihui Liu
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892; , , , ,
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28
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Su C, Xie Y, Pan H, Liu M, Tian H, Shi Y. Organocatalytic synthesis of optically active β-branched α-amino esters via asymmetric biomimetic transamination. Org Biomol Chem 2015; 12:5856-60. [PMID: 24969075 DOI: 10.1039/c4ob00684d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This paper describes an efficient asymmetric biomimetic transamination of α-keto esters with a quinine-derived chiral base as the catalyst, giving a variety of β-branched α-amino esters in 50-96% yield and 87-95% ee.
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Affiliation(s)
- Cunxiang Su
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 10090, China
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Ohanjanian L, Remy KE, Li Y, Cui X, Eichacker PQ. An overview of investigational toxin-directed therapies for the adjunctive management of Bacillus anthracis infection and sepsis. Expert Opin Investig Drugs 2015; 24:851-65. [PMID: 25920540 DOI: 10.1517/13543784.2015.1041587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Sepsis with Bacillus anthracis infection has a very high mortality rate despite appropriate antibiotic and supportive therapies. Over the past 15 years, recent outbreaks in the US and in Europe, coupled with anthrax's bioterrorism weapon potential, have stimulated efforts to develop adjunctive therapies to improve clinical outcomes. Since lethal toxin and edema toxin (LT and ET) make central contributions to the pathogenesis of B. anthracis, these have been major targets in this effort. AREAS COVERED Here, the authors review different investigative biopharmaceuticals that have been recently identified for their therapeutic potential as inhibitors of LT or ET. Among these inhibitors are two antibody preparations that have been included in the Strategic National Stockpile (SNS) and several more that have reached Phase I testing. Presently, however, many of these candidate agents have only been studied in vitro and very few tested in bacteria-challenged models. EXPERT OPINION Although a large number of drugs have been identified as potential therapeutic inhibitors of LT and ET, in most cases their testing has been limited. The use of the two SNS antibody therapies during a large-scale exposure to B. anthracis will be difficult. Further testing and development of agents with oral bioavailability and relatively long shelf lives should be a focus for future research.
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Affiliation(s)
- Lernik Ohanjanian
- National Institutes of Health, Clinical Center, Critical Care Medicine Department , Building 10, Room 2C145, Bethesda, MD 20892 , USA +1 301 402 2914 ; +1 301 402 1213 ;
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Using common spatial distributions of atoms to relate functionally divergent influenza virus N10 and N11 protein structures to functionally characterized neuraminidase structures, toxin cell entry domains, and non-influenza virus cell entry domains. PLoS One 2015; 10:e0117499. [PMID: 25706124 PMCID: PMC4337911 DOI: 10.1371/journal.pone.0117499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 12/24/2014] [Indexed: 11/19/2022] Open
Abstract
The ability to identify the functional correlates of structural and sequence variation in proteins is a critical capability. We related structures of influenza A N10 and N11 proteins that have no established function to structures of proteins with known function by identifying spatially conserved atoms. We identified atoms with common distributed spatial occupancy in PDB structures of N10 protein, N11 protein, an influenza A neuraminidase, an influenza B neuraminidase, and a bacterial neuraminidase. By superposing these spatially conserved atoms, we aligned the structures and associated molecules. We report spatially and sequence invariant residues in the aligned structures. Spatially invariant residues in the N6 and influenza B neuraminidase active sites were found in previously unidentified spatially equivalent sites in the N10 and N11 proteins. We found the corresponding secondary and tertiary structures of the aligned proteins to be largely identical despite significant sequence divergence. We found structural precedent in known non-neuraminidase structures for residues exhibiting structural and sequence divergence in the aligned structures. In N10 protein, we identified staphylococcal enterotoxin I-like domains. In N11 protein, we identified hepatitis E E2S-like domains, SARS spike protein-like domains, and toxin components shared by alpha-bungarotoxin, staphylococcal enterotoxin I, anthrax lethal factor, clostridium botulinum neurotoxin, and clostridium tetanus toxin. The presence of active site components common to the N6, influenza B, and S. pneumoniae neuraminidases in the N10 and N11 proteins, combined with the absence of apparent neuraminidase function, suggests that the role of neuraminidases in H17N10 and H18N11 emerging influenza A viruses may have changed. The presentation of E2S-like, SARS spike protein-like, or toxin-like domains by the N10 and N11 proteins in these emerging viruses may indicate that H17N10 and H18N11 sialidase-facilitated cell entry has been supplemented or replaced by sialidase-independent receptor binding to an expanded cell population that may include neurons and T-cells.
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Abstract
Resistance of important bacterial pathogens to common antimicrobial therapies and the emergence of multidrug-resistant bacteria are increasing at an alarming rate and constitute one of our greatest challenges in the combat of bacterial infection and accompanied diseases. The current shortage of effective drugs, lack of successful prevention measures and only a few new antibiotics in the clinical pipeline demand the development of novel treatment options and alternative antimicrobial therapies. Our increasing understanding of bacterial virulence strategies and the induced molecular pathways of the infectious disease provides novel opportunities to target and interfere with crucial pathogenicity factors or virulence-associated traits of the bacteria while bypassing the evolutionary pressure on the bacterium to develop resistance. In the past decade, numerous new bacterial targets for anti-virulence therapies have been identified, and structure-based tailoring of intervention strategies and screening assays for small-molecule inhibitors of such pathways were successfully established. In this chapter, we will take a closer look at the bacterial virulence-related factors and processes that present promising targets for anti-virulence therapies, recently discovered inhibitory substances and their promises and discuss the challenges, and problems that have to be faced.
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Zambelloni R, Marquez R, Roe AJ. Development of Antivirulence Compounds: A Biochemical Review. Chem Biol Drug Des 2014; 85:43-55. [DOI: 10.1111/cbdd.12430] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 08/20/2014] [Accepted: 08/26/2014] [Indexed: 01/09/2023]
Affiliation(s)
- Riccardo Zambelloni
- Institute of Infection Immunity and Inflammation; University of Glasgow; Sir Graeme Davies Building 120 University Place Glasgow G12 8TA UK
- Institute of Molecular and Cell Biology and Chemistry; University of Glasgow; Joseph Black Building Glasgow G12 8QQ UK
| | - Rudi Marquez
- Institute of Molecular and Cell Biology and Chemistry; University of Glasgow; Joseph Black Building Glasgow G12 8QQ UK
| | - Andrew J. Roe
- Institute of Molecular and Cell Biology and Chemistry; University of Glasgow; Joseph Black Building Glasgow G12 8QQ UK
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Maize KM, Zhang X, Amin EA. Statistical analysis, optimization, and prioritization of virtual screening parameters for zinc enzymes including the anthrax toxin lethal factor. Curr Top Med Chem 2014; 14:2105-14. [PMID: 25373478 DOI: 10.2174/1568026614666141106163011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 09/01/2014] [Accepted: 09/09/2014] [Indexed: 11/22/2022]
Abstract
The anthrax toxin lethal factor (LF) and matrix metalloproteinase-3 (MMP-3, stromelysin-1) are popular zinc metalloenzyme drug targets, with LF primarily responsible for anthrax-related toxicity and host death, while MMP-3 is involved in cancer- and rheumatic disease-related tissue remodeling. A number of in silico screening techniques, most notably docking and scoring, have proven useful for identifying new potential drug scaffolds targeting LF and MMP-3, as well as for optimizing lead compounds and investigating mechanisms of action. However, virtual screening outcomes can vary significantly depending on the specific docking parameters chosen, and systematic statistical significance analyses are needed to prioritize key parameters for screening small molecules against these zinc systems. In the current work, we present a series of chi-square statistical analyses of virtual screening outcomes for cocrystallized LF and MMP-3 inhibitors docked into their respective targets, evaluated by predicted enzyme-inhibitor dissociation constant and root-mean-square deviation (RMSD) between predicted and experimental bound configurations, and we present a series of preferred parameters for use with these systems in the industry-standard Surflex-Dock screening program, for use by researchers utilizing in silico techniques to discover and optimize new scaffolds.
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Affiliation(s)
| | | | - Elizabeth Ambrose Amin
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 717 Delaware St SE, Minneapolis, MN 55416 USA.
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Maize KM, Kurbanov EK, De La Mora-Rey T, Geders TW, Hwang DJ, Walters MA, Johnson RL, Amin EA, Finzel BC. Anthrax toxin lethal factor domain 3 is highly mobile and responsive to ligand binding. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2813-22. [PMID: 25372673 PMCID: PMC4220970 DOI: 10.1107/s1399004714018161] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/07/2014] [Indexed: 12/30/2022]
Abstract
The secreted anthrax toxin consists of three components: the protective antigen (PA), edema factor (EF) and lethal factor (LF). LF, a zinc metalloproteinase, compromises the host immune system primarily by targeting mitogen-activated protein kinase kinases in macrophages. Peptide substrates and small-molecule inhibitors bind LF in the space between domains 3 and 4 of the hydrolase. Domain 3 is attached on a hinge to domain 2 via residues Ile300 and Pro385, and can move through an angular arc of greater than 35° in response to the binding of different ligands. Here, multiple LF structures including five new complexes with co-crystallized inhibitors are compared and three frequently populated LF conformational states termed `bioactive', `open' and `tight' are identified. The bioactive position is observed with large substrate peptides and leaves all peptide-recognition subsites open and accessible. The tight state is seen in unliganded and small-molecule complex structures. In this state, domain 3 is clamped over certain substrate subsites, blocking access. The open position appears to be an intermediate state between these extremes and is observed owing to steric constraints imposed by specific bound ligands. The tight conformation may be the lowest-energy conformation among the reported structures, as it is the position observed with no bound ligand, while the open and bioactive conformations are likely to be ligand-induced.
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Affiliation(s)
- Kimberly M. Maize
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Elbek K. Kurbanov
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Teresa De La Mora-Rey
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Todd W. Geders
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Dong-Jin Hwang
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Michael A. Walters
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Rodney L. Johnson
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Elizabeth A. Amin
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
| | - Barry C. Finzel
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute, University of Minnesota, 8-101 Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
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Nablo BJ, Panchal RG, Bavari S, Nguyen TL, Gussio R, Ribot W, Friedlander A, Chabot D, Reiner JE, Robertson JWF, Balijepalli A, Halverson KM, Kasianowicz JJ. Anthrax toxin-induced rupture of artificial lipid bilayer membranes. J Chem Phys 2014; 139:065101. [PMID: 23947891 DOI: 10.1063/1.4816467] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We demonstrate experimentally that anthrax toxin complexes rupture artificial lipid bilayer membranes when isolated from the blood of infected animals. When the solution pH is temporally acidified to mimic that process in endosomes, recombinant anthrax toxin forms an irreversibly bound complex, which also destabilizes membranes. The results suggest an alternative mechanism for the translocation of anthrax toxin into the cytoplasm.
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Affiliation(s)
- Brian J Nablo
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8120, USA
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Kammanadiminti S, Patnaikuni RK, Comer J, Meister G, Sinclair C, Kodihalli S. Combination therapy with antibiotics and anthrax immune globulin intravenous (AIGIV) is potentially more effective than antibiotics alone in rabbit model of inhalational anthrax. PLoS One 2014; 9:e106393. [PMID: 25226075 PMCID: PMC4165586 DOI: 10.1371/journal.pone.0106393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 08/06/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND We have evaluated the therapeutic efficacy of AIGIV when given in combination with levofloxacin and the effective window of treatment to assess the added benefit provided by AIGIV over standard antibiotic treatment alone in a New Zealand white rabbit model of inhalational anthrax. METHODS Rabbits were exposed to lethal dose of aerosolized spores of Bacillus anthracis (Ames strain) and treated intravenously with either placebo, (normal immune globulin intravenous, IGIV) or 15 U/kg of AIGIV, along with oral levofloxacin treatment at various time points (30-96 hours) after anthrax exposure. RESULTS The majority of treated animals (>88%) survived in both treatment groups when treatment was initiated within 60 hours of post-exposure. However, reduced survival of 55%, 33% and 25% was observed for placebo + levofloxacin group when the treatment was initiated at 72, 84 and 96 hours post-exposure, respectively. Conversely, a survival rate of 65%, 40% and 71% was observed in the AIGIV + levofloxacin treated groups at these time points. CONCLUSIONS The combination of AIGIV with antibiotics provided an improvement in survival compared to levofloxacin treatment alone when treatment was delayed up to 96 hours post-anthrax exposure. Additionally, AIGIV treatment when given as an adjunct therapy at any of the time points tested did not interfere with the efficacy of levofloxacin.
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Affiliation(s)
| | | | - Jason Comer
- Battelle Biomedical Research Center, West Jefferson, Columbus, Ohio, United States of America
| | - Gabriel Meister
- Battelle Biomedical Research Center, West Jefferson, Columbus, Ohio, United States of America
| | - Chris Sinclair
- Department of Clinical Research, Cangene Corporation, Winnipeg, Manitoba, Canada
| | - Shantha Kodihalli
- Department of Clinical Research, Cangene Corporation, Winnipeg, Manitoba, Canada
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Bialecki JB, Weisbecker CS, Attygalle AB. Low-energy collision-induced dissociation mass spectra of protonated p-toluenesulfonamides derived from aliphatic amines. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2014; 25:1068-1078. [PMID: 24676895 DOI: 10.1007/s13361-014-0865-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/15/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Collision-induced fragmentation of protonated N-alkyl-p-toluenesulfonamides primarily undergo either an elimination of the amine to form CH3-(C6H4)-SO2(+) cation (m/z 155) or an alkene to form a cation for the protonated p-toluenesulfonamide (m/z 172). To comprehend the fragmentation pathways, several deuterated analogs of N-decyl-p-toluenesulfonamides were prepared and evaluated. Hypothetically, two mechanisms, both of which involve ion-neutral complexes, can be envisaged. In one mechanism, the S-N bond fragments to produce an intermediate [sulfonyl cation/amine] complex, which dissociates to afford the m/z 155 cation (Pathway A). In the other mechanism, the C-N bond dissociates to produce a different intermediate complex. The fragmentation of this [p-toluenesulfonamide/carbocation] complex eliminates p-toluenesulfonamide and releases the carbocation (Pathway B). Computations carried out by the Hartree-Fock method suggested that the Pathway B is more favorable. However, a peak for the carbocation is observed only when the carbocation formed is relatively stable. For example, the spectrum of N-phenylethyl-p-toluenesulfonamide is dominated by the peak at m/z 105 for the incipient phenylethyl cation, which rapidly isomerizes to the remarkably stable methylbenzyl cation. The peaks for the carbocations are weak or absent in the spectra of most of N-alkyl-p-toluenesulfonamides because alkyl carbocations, such as the decyl cation, rearrange to more stable secondary cations by 1,2-hydride and alkyl shifts. The energy freed is not dissipated, but gets internalized, causing the carbocation to dissociate either by transferring a proton to the sulfonamide or by releasing smaller alkenes to form smaller carbocations. The loss of the positional integrity in this way was proven by deuterium labeling experiments.
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Affiliation(s)
- Jason B Bialecki
- Center for Mass Spectrometry, Department of Chemistry, Chemical Biology and Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07307, USA
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Cheng G, Hao H, Xie S, Wang X, Dai M, Huang L, Yuan Z. Antibiotic alternatives: the substitution of antibiotics in animal husbandry? Front Microbiol 2014; 5:217. [PMID: 24860564 PMCID: PMC4026712 DOI: 10.3389/fmicb.2014.00217] [Citation(s) in RCA: 315] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 04/25/2014] [Indexed: 12/21/2022] Open
Abstract
It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really replace antibiotics remains a controversial issue. This review summarizes recent development and perspectives of alternatives to antibiotics. The mechanism of actions, applications, and prospectives of the alternatives such as immunity modulating agents, bacteriophages and their lysins, antimicrobial peptides, pro-, pre-, and synbiotics, plant extracts, inhibitors targeting pathogenicity (bacterial quorum sensing, biofilm, and virulence), and feeding enzymes are thoroughly discussed. Lastly, the feasibility of alternatives to antibiotics is deeply analyzed. It is hard to conclude that the alternatives might substitute antibiotics in veterinary medicine in the foreseeable future. At the present time, prudent use of antibiotics and the establishment of scientific monitoring systems are the best and fastest way to limit the adverse effects of the abuse of antibiotics and to ensure the safety of animal-derived food and environment.
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Affiliation(s)
- Guyue Cheng
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University Wuhan, China
| | - Haihong Hao
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University Wuhan, China
| | - Shuyu Xie
- National Reference Laboratory of Veterinary Drug Residues, Huazhong Agricultural University Wuhan, China ; MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University Wuhan, China
| | - Xu Wang
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University Wuhan, China
| | - Menghong Dai
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University Wuhan, China
| | - Lingli Huang
- National Reference Laboratory of Veterinary Drug Residues, Huazhong Agricultural University Wuhan, China ; MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University Wuhan, China
| | - Zonghui Yuan
- MOA Laboratory for Risk Assessment of Quality and Safety of Livestock and Poultry Products, Huazhong Agricultural University Wuhan, China ; National Reference Laboratory of Veterinary Drug Residues, Huazhong Agricultural University Wuhan, China ; MOA Key Laboratory for the Detection of Veterinary Drug Residues in Foods, Huazhong Agricultural University Wuhan, China
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Karlyshev AV, Thacker G, Jones MA, Clements MO, Wren BW. Campylobacter jejuni gene cj0511 encodes a serine peptidase essential for colonisation. FEBS Open Bio 2014; 4:468-72. [PMID: 24918062 PMCID: PMC4050187 DOI: 10.1016/j.fob.2014.04.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 03/06/2014] [Accepted: 04/28/2014] [Indexed: 12/24/2022] Open
Abstract
A novel peptidase Cj0511 in an important human bacterial pathogen Campylobacter jejuni has been characterized. Proteolytic properties of Cj0511 protein were detected in whole cell lysates using zymography. Enzymatic studies conducted with a purified protein confirmed the prediction of a serine peptidase. The cj0511 mutant was severely attenuated in a chicken colonisation model, suggesting a role in infection.
According to MEROPS peptidase database, Campylobacter species encode 64 predicted peptidases. However, proteolytic properties of only a few of these proteins have been confirmed experimentally. In this study we identified and characterised a Campylobacter jejuni gene cj0511 encoding a novel peptidase. The proteolytic activity associated with this enzyme was demonstrated in cell lysates. Moreover, enzymatic studies conducted with a purified protein confirmed a prediction of it being a serine peptidase. Furthermore, cj0511 mutant was found to be severely attenuated in chicken colonisation model, suggesting a role of the Cj0511 protein in infection.
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Affiliation(s)
- A V Karlyshev
- The London School of Hygiene & Tropical Medicine, Keppel St, London WC1E 7HT, United Kingdom ; School of Life Sciences, Faculty of Science, Engineering and Computing, Kingston University, Kingston upon Thames, Penrhyn Road, KT1 2EE, United Kingdom
| | - G Thacker
- The London School of Hygiene & Tropical Medicine, Keppel St, London WC1E 7HT, United Kingdom
| | - M A Jones
- School of Veterinary Medicine and Science, University of Nottingham, Loughborough, Sutton Bonnington LE12 5RD, United Kingdom
| | - M O Clements
- School of Biosciences, University of Westminster, 115 New Cavendish Street, London W1B 2UW, United Kingdom
| | - B W Wren
- The London School of Hygiene & Tropical Medicine, Keppel St, London WC1E 7HT, United Kingdom
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Gorantala J, Grover S, Rahi A, Chaudhary P, Rajwanshi R, Sarin NB, Bhatnagar R. Generation of protective immune response against anthrax by oral immunization with protective antigen plant-based vaccine. J Biotechnol 2014; 176:1-10. [PMID: 24548460 DOI: 10.1016/j.jbiotec.2014.01.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 12/30/2013] [Accepted: 01/29/2014] [Indexed: 01/04/2023]
Abstract
In concern with frequent recurrence of anthrax in endemic areas and inadvertent use of its spores as biological weapon, the development of an effective anthrax vaccine suitable for both human and veterinary needs is highly desirable. A simple oral delivery through expression in plant system could offer promising alternative to the current methods that rely on injectable vaccines extracted from bacterial sources. In the present study, we have expressed protective antigen (PA) gene in Indian mustard by Agrobacterium-mediated transformation and in tobacco by plastid transformation. Putative transgenic lines were verified for the presence of transgene and its expression by molecular analysis. PA expressed in transgenic lines was biologically active as evidenced by macrophage lysis assay. Intraperitoneal (i.p.) and oral immunization with plant PA in murine model indicated high serum PA specific IgG and IgA antibody titers. PA specific mucosal immune response was noted in orally immunized groups. Further, antibodies indicated lethal toxin neutralizing potential in-vitro and conferred protection against in-vivo toxin challenge. Oral immunization experiments demonstrated generation of immunoprotective response in mice. Thus, our study examines the feasibility of oral PA vaccine expressed in an edible plant system against anthrax.
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Affiliation(s)
- Jyotsna Gorantala
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Sonam Grover
- Molecular Technology Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Amit Rahi
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Prerna Chaudhary
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ravi Rajwanshi
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Neera Bhalla Sarin
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Rakesh Bhatnagar
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
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Identification of exosite-targeting inhibitors of anthrax lethal factor by high-throughput screening. ACTA ACUST UNITED AC 2014; 19:875-82. [PMID: 22840775 DOI: 10.1016/j.chembiol.2012.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 05/10/2012] [Accepted: 05/17/2012] [Indexed: 12/24/2022]
Abstract
Protease inhibitor discovery has focused almost exclusively on compounds that bind to the active site. Inhibitors targeting protease exosites, regions outside of the active site that influence catalysis, offer potential advantages of increased specificity but are difficult to systematically discover. Here, we describe an assay suitable for detecting exosite-targeting inhibitors of the metalloproteinase anthrax lethal factor (LF) based on cleavage of a full-length mitogen-activated protein kinase kinase (MKK) substrate. We used this assay to screen a small-molecule library and then subjected hits to a secondary screen to exclude compounds that efficiently blocked cleavage of a peptide substrate. We identified a compound that preferentially inhibited cleavage of MKKs compared with peptide substrates and could suppress LF-induced macrophage cytolysis. This approach should be generally applicable to the discovery of exosite-targeting inhibitors of many additional proteases.
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42
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Structure-based pharmacophore modeling and virtual screening to identify novel inhibitors for anthrax lethal factor. Med Chem Res 2014. [DOI: 10.1007/s00044-014-0947-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
INTRODUCTION Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded 'for the development of multiscale models for complex chemical systems' once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial-and-error approach to a minimum. The intentional dissemination of Bacillus anthracis spores in 2001 via the so-called anthrax letters has led to increased efforts, politically and scientifically, to develop medical countermeasures that will protect people from the threat of anthrax bioterrorism. AREAS COVERED This article provides an overview of the recent rational drug design approaches for discovering inhibitors of anthrax toxin. The review also directs the readers to the vast literature on the recognized advances and future possibilities in the field. EXPERT OPINION Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (protective antigen-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, the situation, in our view, is still insecure. Further, the FDA's animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Better identification and validation of anthrax toxin therapeutic targets at the molecular level as well as elucidation of the parameters determining the corresponding therapeutic windows are still necessary for more effective therapeutic options.
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Affiliation(s)
- Ekaterina M Nestorovich
- The Catholic University of America, Department of Biology , Washington, DC , USA +1 202 319 6723 ;
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Bouzianas DG. Potential biological targets ofBacillus anthracisin anti-infective approaches against the threat of bioterrorism. Expert Rev Anti Infect Ther 2014; 5:665-84. [PMID: 17678429 DOI: 10.1586/14787210.5.4.665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The terrorist attacks of 2001 involving anthrax underscore the imperative that safe and effective medical countermeasures should be readily available. Vaccination appears to be the most effective form of mass protection against a biological attack, but the current vaccines have drawbacks that justify the enormous amount of effort currently being put into developing more effective vaccines and other treatment modalities. After providing a comprehensive overview of the organism Bacillus anthracis as a biological weapon and its pathogenicity, this review briefly summarizes the current knowledge vital to the management of anthrax disease. This knowledge has been acquired since 2001 as a result of the progress on anthrax research and focuses on the possible development of improved human anti-infective strategies targeting B. anthracis spore components, as well as strategies based on host-pathogen interactions.
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Affiliation(s)
- Dimitrios G Bouzianas
- Department of Medical Laboratories, Faculty of Health and Care Professions, University-level Technological Educational Institute of Thessaloniki, Greece.
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Echols N, Moriarty NW, Klei HE, Afonine PV, Bunkóczi G, Headd JJ, McCoy AJ, Oeffner RD, Read RJ, Terwilliger TC, Adams PD. Automating crystallographic structure solution and refinement of protein-ligand complexes. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:144-54. [PMID: 24419387 PMCID: PMC3919266 DOI: 10.1107/s139900471302748x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 10/07/2013] [Indexed: 11/29/2022]
Abstract
High-throughput drug-discovery and mechanistic studies often require the determination of multiple related crystal structures that only differ in the bound ligands, point mutations in the protein sequence and minor conformational changes. If performed manually, solution and refinement requires extensive repetition of the same tasks for each structure. To accelerate this process and minimize manual effort, a pipeline encompassing all stages of ligand building and refinement, starting from integrated and scaled diffraction intensities, has been implemented in Phenix. The resulting system is able to successfully solve and refine large collections of structures in parallel without extensive user intervention prior to the final stages of model completion and validation.
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Affiliation(s)
- Nathaniel Echols
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
| | - Nigel W. Moriarty
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
| | - Herbert E. Klei
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
| | - Pavel V. Afonine
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
| | - Gábor Bunkóczi
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Cambridge CB2 0XY, England
| | - Jeffrey J. Headd
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
| | - Airlie J. McCoy
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Cambridge CB2 0XY, England
| | - Robert D. Oeffner
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Cambridge CB2 0XY, England
| | - Randy J. Read
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Cambridge CB2 0XY, England
| | | | - Paul D. Adams
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8235, USA
- Department of Bioengineering, University of California at Berkeley, Berkeley, CA 94720-1762, USA
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Brojatsch J, Casadevall A, Goldman DL. Molecular determinants for a cardiovascular collapse in anthrax. Front Biosci (Elite Ed) 2014; 6:139-47. [PMID: 24389148 DOI: 10.2741/e697] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Bacillus anthracis releases two bipartite proteins, lethal toxin and edema factor, that contribute significantly to the progression of anthrax-associated shock. As blocking the anthrax toxins prevents disease, the toxins are considered the main virulence factors of the bacterium. The anthrax bacterium and the anthrax toxins trigger multi-organ failure associated with enhanced vascular permeability, hemorrhage and cardiac dysfunction in animal challenge models. A recent study using mice that either lacked the anthrax toxin receptor in specific cells and corresponding mice expressing the receptor in specific cell types demonstrated that cardiovascular cells are critical for disease mediated by anthrax lethal toxin. These studies are consistent with involvement of the cardiovascular system, and with an increase of cardiac failure markers observed in human anthrax and in animal models using B. anthracis and anthrax toxins. This review discusses the current state of knowledge regarding the pathophysiology of anthrax and tries to provide a mechanistic model and molecular determinants for the circulatory shock in anthrax.
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Affiliation(s)
- Jurgen Brojatsch
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
| | - David L Goldman
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY
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Abrami L, Brandi L, Moayeri M, Brown MJ, Krantz BA, Leppla SH, van der Goot FG. Hijacking multivesicular bodies enables long-term and exosome-mediated long-distance action of anthrax toxin. Cell Rep 2013; 5:986-96. [PMID: 24239351 PMCID: PMC3866279 DOI: 10.1016/j.celrep.2013.10.019] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/01/2013] [Accepted: 10/11/2013] [Indexed: 12/21/2022] Open
Abstract
Anthrax lethal toxin is a classical AB toxin comprised of two components: protective antigen (PA) and lethal factor (LF). Here, we show that following assembly and endocytosis, PA forms a channel that translocates LF, not only into the cytosol, but also into the lumen of endosomal intraluminal vesicles (ILVs). These ILVs can fuse and release LF into the cytosol, where LF can proteolyze and disable host targets. We find that LF can persist in ILVs for days, fully sheltered from proteolytic degradation, both in vitro and in vivo. During this time, ILV-localized LF can be transmitted to daughter cells upon cell division. In addition, LF-containing ILVs can be delivered to the extracellular medium as exosomes. These can deliver LF to the cytosol of naive cells in a manner that is independent of the typical anthrax toxin receptor-mediated trafficking pathway, while being sheltered from neutralizing extracellular factors of the immune system.
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Affiliation(s)
- Laurence Abrami
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Lucia Brandi
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
| | - Mahtab Moayeri
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, U.S.A
| | - Michael J. Brown
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, 94720, U.S.A
| | - Bryan A. Krantz
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, 94720, U.S.A
- Department of Chemistry, University of California, Berkeley, CA, 94720, U.S.A
| | - Stephen H. Leppla
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, U.S.A
| | - F. G. van der Goot
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, CH-1015 Lausanne, Switzerland
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Williams JD, Khan AR, Cardinale SC, Butler MM, Bowlin TL, Peet NP. Small molecule inhibitors of anthrax lethal factor toxin. Bioorg Med Chem 2013; 22:419-34. [PMID: 24290062 DOI: 10.1016/j.bmc.2013.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/29/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
Abstract
This manuscript describes the preparation of new small molecule inhibitors of Bacillus anthracis lethal factor. Our starting point was the symmetrical, bis-quinolinyl compound 1 (NSC 12155). Optimization of one half of this molecule led to new LF inhibitors that were desymmetrized to afford more drug-like compounds.
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Affiliation(s)
- John D Williams
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Atiyya R Khan
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Steven C Cardinale
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Michelle M Butler
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Terry L Bowlin
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Norton P Peet
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States.
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Chang HH, Wang TP, Chen PK, Lin YY, Liao CH, Lin TK, Chiang YW, Lin WB, Chiang CY, Kau JH, Huang HH, Hsu HL, Liao CY, Sun DS. Erythropoiesis suppression is associated with anthrax lethal toxin-mediated pathogenic progression. PLoS One 2013; 8:e71718. [PMID: 23977125 PMCID: PMC3747219 DOI: 10.1371/journal.pone.0071718] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/01/2013] [Indexed: 01/01/2023] Open
Abstract
Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34+-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax.
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Affiliation(s)
- Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Tsung-Pao Wang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Po-Kong Chen
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Yo-Yin Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Hsien Liao
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ting-Kai Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ya-Wen Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Wen-Bin Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Yu Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Jyh-Hwa Kau
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Yuan Liao
- Department of Obstetrics and Gynecology, Mennonite Christian HospitalHualien, Taiwan
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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Small-molecule inhibitors of lethal factor protease activity protect against anthrax infection. Antimicrob Agents Chemother 2013; 57:4139-45. [PMID: 23774434 DOI: 10.1128/aac.00941-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax, manifests its pathogenesis through the action of two secreted toxins. The bipartite lethal and edema toxins, a combination of lethal factor or edema factor with the protein protective antigen, are important virulence factors for this bacterium. We previously developed small-molecule inhibitors of lethal factor proteolytic activity (LFIs) and demonstrated their in vivo efficacy in a rat lethal toxin challenge model. In this work, we show that these LFIs protect against lethality caused by anthrax infection in mice when combined with subprotective doses of either antibiotics or neutralizing monoclonal antibodies that target edema factor. Significantly, these inhibitors provided protection against lethal infection when administered as a monotherapy. As little as two doses (10 mg/kg) administered at 2 h and 8 h after spore infection was sufficient to provide a significant survival benefit in infected mice. Administration of LFIs early in the infection was found to inhibit dissemination of vegetative bacteria to the organs in the first 32 h following infection. In addition, neutralizing antibodies against edema factor also inhibited bacterial dissemination with similar efficacy. Together, our findings confirm the important roles that both anthrax toxins play in establishing anthrax infection and demonstrate the potential for small-molecule therapeutics targeting these proteins.
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