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Liao F, Ye Z, Cheng J, Zhu J, Chen X, Zhou X, Wang T, Jiang Y, Ma C, Zhou M, Chen T, Shaw C, Wang L. Discovery and engineering of a novel peptide, Temporin-WY2, with enhanced in vitro and in vivo efficacy against multi-drug resistant bacteria. Sci Rep 2024; 14:18769. [PMID: 39138237 PMCID: PMC11322164 DOI: 10.1038/s41598-024-67777-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Accepted: 07/15/2024] [Indexed: 08/15/2024] Open
Abstract
Infections by drug-resistant microorganisms are a threat to global health and antimicrobial peptides are considered to be a new hope for their treatment. Temporin-WY2 was identified from the cutaneous secretion of the Ranidae frog, Amolops wuyiensis. It presented with a potent anti-Gram-positive bacterial efficacy, but its activity against Gram-negative bacteria and cancer cell lines was unremarkable. Also, it produced a relatively high lytic effect on horse erythrocytes. For further improvement of its functions, a perfect amphipathic analogue, QUB-1426, and two lysine-clustered analogues, 6K-WY2 and 6K-1426, were synthesised and investigated. The modified peptides were found to be between 8- and 64-fold more potent against Gram-negative bacteria than the original peptide. Additionally, the 6K analogues showed a rapid killing rate. Also, their antiproliferation activities were more than 100-fold more potent than the parent peptide. All of the peptides that were examined demonstrated considerable biofilm inhibition activity. Moreover, QUB-1426, 6K-WY2 and 6K-1426, demonstrated in vivo antimicrobial activity against MRSA and E. coli in an insect larvae model. Despite observing a slight increase in the hemolytic activity and cytotoxicity of the modified peptides, they still demonstrated a improved therapeutic index. Overall, QUB-1426, 6K-WY2 and 6K-1426, with dual antimicrobial and anticancer functions, are proposed as putative drug candidates for the future.
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Affiliation(s)
- Fengting Liao
- School of Food and Pharmaceutical Engineering, Zhaoqing University, Zhaoqing, 526061, China
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, ShaoGuan University, Shaoguan, China
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Zhuming Ye
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, ShaoGuan University, Shaoguan, China
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Jinsheng Cheng
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, ShaoGuan University, Shaoguan, China
| | - Jianhua Zhu
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, ShaoGuan University, Shaoguan, China
| | - Xiaoling Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK.
| | - Xiaowei Zhou
- Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal Resources in Northern Region, ShaoGuan University, Shaoguan, China.
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK.
| | - Tao Wang
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Yangyang Jiang
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Chengbang Ma
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Mei Zhou
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Tianbao Chen
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Chris Shaw
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
| | - Lei Wang
- Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK
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2
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Lipid Microenvironment Modulates the Pore-Forming Ability of Polymyxin B. Antibiotics (Basel) 2022; 11:antibiotics11101445. [PMID: 36290103 PMCID: PMC9598075 DOI: 10.3390/antibiotics11101445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022] Open
Abstract
The ability of polymyxin B, an antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria as a last-line therapeutic option, to form ion pores in model membranes composed of various phospholipids and lipopolysaccharides was studied. Our data demonstrate that polymyxin B predominantly interacts with negatively charged lipids. Susceptibility decreases as follows: Kdo2-Lipid A >> DOPG ≈ DOPS >> DPhPG ≈ TOCL ≈ Lipid A. The dimer and hexamer of polymyxin B are involved in the pore formation in DOPG(DOPS)- and Kdo2-Lipid A-enriched bilayers, respectively. The pore-forming ability of polymyxin B significantly depends on the shape of membrane lipids, which indicates that the antibiotic produces toroidal lipopeptide-lipid pores. Small amphiphilic molecules diminishing the membrane dipole potential and inducing positive curvature stress were shown to be agonists of pore formation by polymyxin B and might be used to develop innovative lipopeptide-based formulations.
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3
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Ginez LD, Osorio A, Vázquez-Ramírez R, Arenas T, Mendoza L, Camarena L, Poggio S. Changes in fluidity of the E. coli outer membrane in response to temperature, divalent cations and polymyxin-B show two different mechanisms of membrane fluidity adaptation. FEBS J 2022; 289:3550-3567. [PMID: 35038363 DOI: 10.1111/febs.16358] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/23/2021] [Accepted: 01/13/2022] [Indexed: 12/28/2022]
Abstract
The outer membrane (OM) is an essential component of the Gram-negative bacterial cell envelope. Restricted diffusion of integral OM proteins and lipopolysaccharide (LPS) that constitute the outer leaflet of the OM support a model in which the OM is in a semi-crystalline state. The low fluidity of the OM has been suggested to be an important property of this membrane that even contributes to cell rigidity. The LPS characteristics strongly determine the properties of the OM and the LPS layer fluidity has been measured using different techniques that require specific conditions or are technically challenging. Here, we characterize the Escherichia coli LPS fluidity by evaluating the lateral diffusion of the styryl dye FM4-64FX in fluorescence recovery after photobleaching experiments. This technique allowed us to determine the effect of different conditions and genetic backgrounds on the LPS fluidity. Our results show that a fraction of the LPS can slowly diffuse and that the fluidity of the LPS layer adapts by modifying the diffusion of the LPS and the fraction of mobile LPS molecules.
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Affiliation(s)
- Luis David Ginez
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Aurora Osorio
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Ricardo Vázquez-Ramírez
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Thelma Arenas
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Luis Mendoza
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Laura Camarena
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
| | - Sebastian Poggio
- Departamento Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México
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4
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Jiang X, Patil NA, Azad MAK, Wickremasinghe H, Yu H, Zhao J, Zhang X, Li M, Gong B, Wan L, Ma W, Thompson PE, Yang K, Yuan B, Schreiber F, Wang L, Velkov T, Roberts KD, Li J. A novel chemical biology and computational approach to expedite the discovery of new-generation polymyxins against life-threatening Acinetobacter baumannii. Chem Sci 2021; 12:12211-12220. [PMID: 34667587 PMCID: PMC8457388 DOI: 10.1039/d1sc03460j] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/12/2021] [Indexed: 01/20/2023] Open
Abstract
Multidrug-resistant Gram-negative bacteria represent a major medical challenge worldwide. New antibiotics are desperately required with 'old' polymyxins often being the only available therapeutic option. Here, we systematically investigated the structure-activity relationship (SAR) of polymyxins using a quantitative lipidomics-informed outer membrane (OM) model of Acinetobacter baumannii and a series of chemically synthesized polymyxin analogs. By integrating chemical biology and all-atom molecular dynamics simulations, we deciphered how each residue of the polymyxin molecule modulated its conformational folding and specific interactions with the bacterial OM. Importantly, a novel designed polymyxin analog FADDI-287 with predicted stronger OM penetration showed improved in vitro antibacterial activity. Collectively, our study provides a novel chemical biology and computational strategy to expedite the discovery of new-generation polymyxins against life-threatening Gram-negative 'superbugs'.
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Affiliation(s)
- Xukai Jiang
- National Glycoengineering Research Center, Shandong University Qingdao China
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Nitin A Patil
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Mohammad A K Azad
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Hasini Wickremasinghe
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Heidi Yu
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Jinxin Zhao
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Xinru Zhang
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Mengyao Li
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Bin Gong
- School of Software, Shandong University Jinan China
| | - Lin Wan
- School of Software, Shandong University Jinan China
| | - Wendong Ma
- Centre for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University Suzhou China
| | - Philip E Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Science, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University Melbourne Australia
| | - Kai Yang
- Centre for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University Suzhou China
| | - Bing Yuan
- Centre for Soft Condensed Matter Physics and Interdisciplinary Research, School of Physical Science and Technology, Soochow University Suzhou China
| | - Falk Schreiber
- Department of Computer and Information Science, University of Konstanz Konstanz Germany
- Faculty of Information Technology, Monash University Melbourne Australia
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University Qingdao China
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, University of Melbourne Melbourne Australia
| | - Kade D Roberts
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
| | - Jian Li
- Biomedicine Discovery Institute, Infection & Immunity Program, Monash University Melbourne Australia +61 3 9905 6450 +61 3 9903 9702
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5
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Abstract
Antibiotic resistance is a major global health challenge and, worryingly, several key Gram negative pathogens can become resistant to most currently available antibiotics. Polymyxins have been revived as a last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacterales. Polymyxins were first discovered in the late 1940s but were abandoned soon after their approval in the late 1950s as a result of toxicities (e.g., nephrotoxicity) and the availability of "safer" antibiotics approved at that time. Therefore, knowledge on polymyxins had been scarce until recently, when enormous efforts have been made by several research teams around the world to elucidate the chemical, microbiological, pharmacokinetic/pharmacodynamic, and toxicological properties of polymyxins. One of the major achievements is the development of the first scientifically based dosage regimens for colistin that are crucial to ensure its safe and effective use in patients. Although the guideline has not been developed for polymyxin B, a large clinical trial is currently being conducted to optimize its clinical use. Importantly, several novel, safer polymyxin-like lipopeptides are developed to overcome the nephrotoxicity, poor efficacy against pulmonary infections, and narrow therapeutic windows of the currently used polymyxin B and colistin. This review discusses the latest achievements on polymyxins and highlights the major challenges ahead in optimizing their clinical use and discovering new-generation polymyxins. To save lives from the deadly infections caused by Gram negative "superbugs," every effort must be made to improve the clinical utility of the last-line polymyxins. SIGNIFICANCE STATEMENT: Antimicrobial resistance poses a significant threat to global health. The increasing prevalence of multidrug-resistant (MDR) bacterial infections has been highlighted by leading global health organizations and authorities. Polymyxins are a last-line defense against difficult-to-treat MDR Gram negative pathogens. Unfortunately, the pharmacological information on polymyxins was very limited until recently. This review provides a comprehensive overview on the major achievements and challenges in polymyxin pharmacology and clinical use and how the recent findings have been employed to improve clinical practice worldwide.
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Affiliation(s)
- Sue C Nang
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Mohammad A K Azad
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Tony Velkov
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Qi Tony Zhou
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Jian Li
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
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6
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Chen DJ, Cui AL, Chen JR, Yang P, Jin J, Shao L, Li ZR. The Low-Alkalinity Polymyxin Derivative, AL-6, Shows High Activity Against Multidrug-Resistant Acinetobacter baumannii Clinical Isolates In Vitro and A. baumannii ATCC 19606 In Vivo: Preliminary Analysis of the Antibacterial Mechanism. Microb Drug Resist 2021; 27:933-941. [PMID: 33544031 DOI: 10.1089/mdr.2019.0474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Polymyxin B and colistin (polymyxin E) are increasingly used as the last line of therapy for infections caused by multidrug-resistant (MDR) gram-negative pathogens. However, nephrotoxicity is still a limiting factor for the use of polymyxin. Therefore, better tolerated and more effective polymyxin derivatives are urgently needed. In this study, we aimed to evaluate the activity of the low-alkalinity polymyxin derivative, AL-6, against MDR Acinetobacter baumannii (Ab) clinical isolates in vitro and A. baumannii ATCC 19606 in vivo. Additionally, we performed a preliminarily study of the antibacterial mechanism. AL-6 showed much higher activity (0.125-0.25 μg/mL) against MDR A. baumannii clinical isolates than polymyxin E2 (PE2, 0.5-1 μg/mL). AL-6 also showed much higher activity (0.5-256 μg/mL) against polymyxin-resistant strains than PE2 (16-1024 μg/mL). Additionally, AL-6 showed slow resistance against A. baumannii. AL-6 also increased the survival rates of mice by 10% at 48 h compared with PE2 (5 mg/kg). AL-6 could be used at a dose of up to 10 mg/kg, increasing the survival rate to 30% at 72 h after infection. A preliminary study of the antibacterial mechanism showed that AL-6 permeabilized the outer membrane and destroyed cell membrane integrity. Moreover, there was a substantial increase in zeta potential (i.e., less negative) upon AL-6 exposure for A. baumannii. Overall, AL-6 carrying only four positive charges showed high activity against A. baumannii in vitro by disrupting cell membrane integrity. Higher doses of AL-6 could increase survival rates of mice. Thus, AL-6 may have potential applications as a bactericidal agent.
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Affiliation(s)
- Dai-Jie Chen
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - A-Long Cui
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jia-Rong Chen
- State Key Laboratory of New Drug and Pharmaceutical Process, Shanghai Institute of Pharmaceutical Industry, Shanghai, China
| | - Ping Yang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Jin
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lei Shao
- Microbial Pharmacology Laboratory, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Zhuo-Rong Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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7
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Swarbrick JD, Karas JA, Li J, Velkov T. Structure of micelle bound cationic peptides by NMR spectroscopy using a lanthanide shift reagent. Chem Commun (Camb) 2020; 56:2897-2900. [PMID: 32037418 DOI: 10.1039/c9cc09207b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
[Tm(DPA)3]3- was used to generate multiple, paramagnetic nuclear Overhauser effect NMR spectra of cationic peptides when weakly bound to a lipopolysaccharide micelle. Increased spectral resolution combined with a marked increase in the number of distance restraints yielded high resolution structures of polymyxin and MSI-594 in the liposaccharide bound state.
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Affiliation(s)
- James D Swarbrick
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria 3010, Australia.
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8
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Study of the structure-activity relationship of polymyxin analogues. Bioorg Med Chem Lett 2018; 28:2713-2716. [DOI: 10.1016/j.bmcl.2018.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/06/2018] [Accepted: 03/11/2018] [Indexed: 12/30/2022]
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9
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Morrison LJ, Chai W, Rosenberg JA, Henkelman G, Brodbelt JS. Characterization of hydrogen bonding motifs in proteins: hydrogen elimination monitoring by ultraviolet photodissociation mass spectrometry. Phys Chem Chem Phys 2018; 19:20057-20074. [PMID: 28722742 DOI: 10.1039/c7cp04073c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Determination of structure and folding of certain classes of proteins remains intractable by conventional structural characterization strategies and has spurred the development of alternative methodologies. Mass spectrometry-based approaches have a unique capacity to differentiate protein heterogeneity due to the ability to discriminate populations, whether minor or major, featuring modifications or complexation with non-covalent ligands on the basis of m/z. Cleavage of the peptide backbone can be further utilized to obtain residue-specific structural information. Here, hydrogen elimination monitoring (HEM) upon ultraviolet photodissociation (UVPD) of proteins transferred to the gas phase via nativespray ionization is introduced as an innovative approach to deduce backbone hydrogen bonding patterns. Using well-characterized peptides and a series of proteins, prediction of the engagement of the amide carbonyl oxygen of the protein backbone in hydrogen bonding using UVPD-HEM is demonstrated to show significant agreement with the hydrogen-bonding motifs derived from molecular dynamics simulations and X-ray crystal structures.
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10
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Han ML, Velkov T, Zhu Y, Roberts KD, Le Brun AP, Chow SH, Gutu AD, Moskowitz SM, Shen HH, Li J. Polymyxin-Induced Lipid A Deacylation in Pseudomonas aeruginosa Perturbs Polymyxin Penetration and Confers High-Level Resistance. ACS Chem Biol 2018; 13:121-130. [PMID: 29182311 DOI: 10.1021/acschembio.7b00836] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Polymyxins are last-line antibiotics against life-threatening multidrug-resistant Gram-negative bacteria. Unfortunately, polymyxin resistance is increasingly reported, leaving a total lack of therapies. Using lipidomics and transcriptomics, we discovered that polymyxin B induced lipid A deacylation via pagL in both polymyxin-resistant and -susceptible Pseudomonas aeruginosa. Our results demonstrated that the deacylation of lipid A is an "innate immunity" response to polymyxins and a key compensatory mechanism to the aminoarabinose modification to confer high-level polymyxin resistance in P. aeruginosa. Furthermore, cutting-edge neutron reflectometry studies revealed that an assembled outer membrane (OM) with the less hydrophobic penta-acylated lipid A decreased polymyxin B penetration, compared to the hexa-acylated form. Polymyxin analogues with enhanced hydrophobicity displayed superior penetration into the tail regions of the penta-acylated lipid A OM. Our findings reveal a previously undiscovered mechanism of polymyxin resistance, wherein polymyxin-induced lipid A remodeling affects the OM packing and hydrophobicity, perturbs polymyxin penetration, and thereby confers high-level resistance.
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Affiliation(s)
- Mei-Ling Han
- Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville, Victoria 3052, Australia
- Monash
Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Tony Velkov
- Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville, Victoria 3052, Australia
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Yan Zhu
- Monash
Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Kade D. Roberts
- Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville, Victoria 3052, Australia
| | - Anton P. Le Brun
- Australian
Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee
DC, New South Wales 2232, Australia
| | - Seong Hoong Chow
- Monash
Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Alina D. Gutu
- Department
of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts United States
| | | | - Hsin-Hui Shen
- Monash
Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- Department
of Materials Science and Engineering, Faculty of Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jian Li
- Monash
Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
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11
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Rabanal F, Cajal Y. Recent advances and perspectives in the design and development of polymyxins. Nat Prod Rep 2017. [PMID: 28628170 DOI: 10.1039/c7np00023e] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Covering: 1947-early 2017, particularly from 2005-early 2017The rise of bacterial pathogens with acquired resistance to almost all available antibiotics is becoming a serious public health issue. Polymyxins, antibiotics that were mostly abandoned a few decades ago because of toxicity concerns, are ultimately considered as a last-line therapy to treat infections caused by multi-drug resistant Gram-negative bacteria. This review surveys the progress in understanding polymyxin structure, and their chemistry, mechanisms of antibacterial activity and nephrotoxicity, biomarkers, synergy and combination with other antimicrobial agents and antibiofilm properties. An update of recent efforts in the design and development of a new generation of polymyxin drugs is also discussed. A novel approach considering the modification of the scaffold of polymyxins to integrate metabolism and detoxification issues into the drug design process is a promising new line to potentially prevent accumulation in the kidneys and reduce nephrotoxicity.
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Affiliation(s)
- Francesc Rabanal
- Organic Chemistry Section, Department of Inorganic and Organic Chemistry, Faculty of Chemistry, University of Barcelona, Spain.
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12
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Transcriptomic Analysis of the Activity of a Novel Polymyxin against Staphylococcus aureus. mSphere 2016; 1:mSphere00119-16. [PMID: 27471750 PMCID: PMC4963539 DOI: 10.1128/msphere.00119-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 06/15/2016] [Indexed: 12/11/2022] Open
Abstract
S. aureus is currently one of the most pervasive multidrug-resistant pathogens and commonly causes nosocomial infections. Clinicians are faced with a dwindling armamentarium to treat infections caused by S. aureus, as resistance develops to current antibiotics. This accentuates the urgent need for antimicrobial drug discovery. In the present study, we characterized the global gene expression profile of S. aureus treated with FADDI-019, a novel synthetic polymyxin analogue. In contrast to the concentration-dependent killing and rapid regrowth in Gram-negative bacteria treated with polymyxin B and colistin, FADDI-019 killed S. aureus progressively without regrowth at 24 h. Notably, FADDI-019 activated several vancomycin resistance genes and significantly downregulated the expression of a number of virulence determinants and enterotoxin genes. A synergistic combination with sulfamethoxazole was predicted by pathway analysis and demonstrated experimentally. This is the first study revealing the transcriptomics of S. aureus treated with a novel synthetic polymyxin analog. Polymyxin B and colistin are exclusively active against Gram-negative pathogens and have been used in the clinic as a last-line therapy. In this study, we investigated the antimicrobial activity of a novel polymyxin, FADDI-019, against Staphylococcus aureus. MIC and time-kill assays were employed to measure the activity of FADDI-019 against S. aureus ATCC 700699. Cell morphology was examined with scanning electron microscopy (SEM), and cell membrane polarity was measured using flow cytometry. Transcriptome changes caused by FADDI-019 treatment were investigated using transcriptome sequencing (RNA-Seq). Pathway analysis was conducted to examine the mechanism of the antibacterial activity of FADDI-019 and to rationally design a synergistic combination. Polymyxin B and colistin were not active against S. aureus strains with MICs of >128 mg/liter; however, FADDI-019 had a MIC of 16 mg/liter. Time-kill assays revealed that no S. aureus regrowth was observed after 24 h at 2× to 4× MIC of FADDI-019. Scanning electron microscopy (SEM) and flow cytometry results indicated that FADDI-019 treatment had no effect on cell morphology but caused membrane depolarization. The vancomycin resistance genes vraRS, as well as the VraRS regulon, were activated by FADDI-019. Virulence determinants controlled by SaeRS and the expression of enterotoxin genes yent2, sei, sem, and seo were significantly downregulated by FADDI-019. Pathway analysis of transcriptomic data was predictive of a synergistic combination comprising FADDI-019 and sulfamethoxazole. Our study is the first to examine the mechanism of the killing of a novel polymyxin against S. aureus. We also show the potential of transcriptomic and pathway analysis as tools to design synergistic antibiotic combinations. IMPORTANCES. aureus is currently one of the most pervasive multidrug-resistant pathogens and commonly causes nosocomial infections. Clinicians are faced with a dwindling armamentarium to treat infections caused by S. aureus, as resistance develops to current antibiotics. This accentuates the urgent need for antimicrobial drug discovery. In the present study, we characterized the global gene expression profile of S. aureus treated with FADDI-019, a novel synthetic polymyxin analogue. In contrast to the concentration-dependent killing and rapid regrowth in Gram-negative bacteria treated with polymyxin B and colistin, FADDI-019 killed S. aureus progressively without regrowth at 24 h. Notably, FADDI-019 activated several vancomycin resistance genes and significantly downregulated the expression of a number of virulence determinants and enterotoxin genes. A synergistic combination with sulfamethoxazole was predicted by pathway analysis and demonstrated experimentally. This is the first study revealing the transcriptomics of S. aureus treated with a novel synthetic polymyxin analog.
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13
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Velkov T, Yun B, Schneider EK, Azad MAK, Dolezal O, Morris FC, Nation RL, Wang J, Chen K, Yu HH, Wang L, Thompson PE, Roberts KD, Li J. A Novel Chemical Biology Approach for Mapping of Polymyxin Lipopeptide Antibody Binding Epitopes. ACS Infect Dis 2016; 2:341-51. [PMID: 27627202 DOI: 10.1021/acsinfecdis.6b00031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Polymyxins B and E (i.e., colistin) are a family of naturally occurring lipopeptide antibiotics that are our last line of defense against multidrug resistant (MDR) Gram-negative pathogens. Unfortunately, nephrotoxicity is a dose-limiting factor for polymyxins that limits their clinical utility. Our recent studies demonstrate that polymyxin-induced nephrotoxicity is a result of their extensive accumulation in renal tubular cells. The design and development of safer, novel polymyxin lipopeptides is hampered by our limited understanding of their complex structure-nephrotoxicity relationships. This is the first study to employ a novel targeted chemical biology approach to map the polymyxin recognition epitope of a commercially available polymyxin mAb and demonstrate its utility for mapping the kidney distribution of a novel, less nephrotoxic polymyxin lipopeptide. Eighteen novel polymyxin lipopeptide analogues were synthesized with modifications in the polymyxin core domains, namely, the N-terminal fatty acyl region, tripeptide linear segment, and cyclic heptapeptide. Surface plasmon resonance epitope mapping revealed that the monoclonal antibody (mAb) recognition epitope consisted of the hydrophobic domain (N-terminal fatty acyl and position 6/7) and diaminobutyric acid (Dab) residues at positions 3, 5, 8, and 9 of the polymyxin molecule. Structural diversity within the hydrophobic domains and Dab 3 position are tolerated. Enlightened with an understating of the structure-binding relationships between the polymyxin mAb and the core polymyxin scaffold, we can now rationally employ the mAb to probe the kidney distribution of novel polymyxin lipopeptides. This information will be vital in the design of novel, safer polymyxins through chemical tailoring of the core scaffold and exploration of the elusive/complex polymyxin structure-nephrotoxicity relationships.
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Affiliation(s)
| | | | | | | | - Olan Dolezal
- CSIRO Manufacturing, Parkville, Victoria 3052, Australia
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Knolhoff AM, Zheng J, McFarland MA, Luo Y, Callahan JH, Brown EW, Croley TR. Identification and Structural Characterization of Naturally-Occurring Broad-Spectrum Cyclic Antibiotics Isolated from Paenibacillus. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1768-1779. [PMID: 26250559 DOI: 10.1007/s13361-015-1190-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/24/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
The rise of antimicrobial resistance necessitates the discovery and/or production of novel antibiotics. Isolated strains of Paenibacillus alvei were previously shown to exhibit antimicrobial activity against a number of pathogens, such as E. coli, Salmonella, and methicillin-resistant Staphylococcus aureus (MRSA). The responsible antimicrobial compounds were isolated from these Paenibacillus strains and a combination of low and high resolution mass spectrometry with multiple-stage tandem mass spectrometry was used for identification. A group of closely related cyclic lipopeptides was identified, differing primarily by fatty acid chain length and one of two possible amino acid substitutions. Variation in the fatty acid length resulted in mass differences of 14 Da and yielded groups of related MS(n) spectra. Despite the inherent complexity of MS/MS spectra of cyclic compounds, straightforward analysis of these spectra was accomplished by determining differences in complementary product ion series between compounds that differ in molecular weight by 14 Da. The primary peptide sequence assignment was confirmed through genome mining; the combination of these analytical tools represents a workflow that can be used for the identification of complex antibiotics. The compounds also share amino acid sequence similarity to a previously identified broad-spectrum antibiotic isolated from Paenibacillus. The presence of such a wide distribution of related compounds produced by the same organism represents a novel class of broad-spectrum antibiotic compounds.
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Affiliation(s)
- Ann M Knolhoff
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA.
| | - Jie Zheng
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
| | - Melinda A McFarland
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
| | - Yan Luo
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
| | - John H Callahan
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
| | - Eric W Brown
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
| | - Timothy R Croley
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, HFS-707, 5100 Paint Branch Pkwy, College Park, MD, 20740, USA
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15
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Magee TV, Brown MF, Starr JT, Ackley DC, Abramite JA, Aubrecht J, Butler A, Crandon JL, Dib-Hajj F, Flanagan ME, Granskog K, Hardink JR, Huband MD, Irvine R, Kuhn M, Leach KL, Li B, Lin J, Luke DR, MacVane SH, Miller AA, McCurdy S, McKim JM, Nicolau DP, Nguyen TT, Noe MC, O’Donnell JP, Seibel SB, Shen Y, Stepan AF, Tomaras AP, Wilga PC, Zhang L, Xu J, Chen JM. Discovery of Dap-3 Polymyxin Analogues for the Treatment of Multidrug-Resistant Gram-Negative Nosocomial Infections. J Med Chem 2013; 56:5079-93. [DOI: 10.1021/jm400416u] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Thomas V. Magee
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Matthew F. Brown
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Jeremy T. Starr
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - David C. Ackley
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Joseph A. Abramite
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Jiri Aubrecht
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Andrew Butler
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Jared L. Crandon
- Center
for Anti-Infective Research
and Development, Hartford Hospital, Hartford,
Connecticut 06102, United States
| | - Fadia Dib-Hajj
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Mark E. Flanagan
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Karl Granskog
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Joel R. Hardink
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Michael D. Huband
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Rebecca Irvine
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Michael Kuhn
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Karen L. Leach
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Bryan Li
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Jian Lin
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - David R. Luke
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Shawn H. MacVane
- Center
for Anti-Infective Research
and Development, Hartford Hospital, Hartford,
Connecticut 06102, United States
| | - Alita A. Miller
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Sandra McCurdy
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | | | - David P. Nicolau
- Center
for Anti-Infective Research
and Development, Hartford Hospital, Hartford,
Connecticut 06102, United States
| | - Thuy-Trinh Nguyen
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Mark C. Noe
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - John P. O’Donnell
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Scott B. Seibel
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Yue Shen
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Antonia F. Stepan
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Andrew P. Tomaras
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
| | - Paul C. Wilga
- CeeTox, Inc., Kalamazoo, Michigan 49008,
United States
| | - Li Zhang
- WuXi AppTech Co., Ltd., Shanghai, P.R. China
| | | | - Jinshan Michael Chen
- Pfizer Worldwide Research & Development, Pfizer, Inc., Groton, Connecticut 06340, United States
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16
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Azzopardi EA, Boyce DE, Thomas DW, Dickson WA. Colistin in burn intensive care: back to the future? Burns 2012; 39:7-15. [PMID: 22871554 DOI: 10.1016/j.burns.2012.07.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 06/19/2012] [Accepted: 07/12/2012] [Indexed: 10/28/2022]
Abstract
Colistin is a venerable antibiotic whose fortunes have been revived by its excellent activity, the diminishing output of novel clinically effective antibiotics and the increasing importance of MDR infection in burn surgery, both in the civilian and military arenas. This review synthesizes current evidence on the usage of colistin in burn surgery including the structure-activity relationship; dosing, pharmacokinetics/pharmacodynamic (PK/PD), analytic methods, resistance and current research efforts into the redevelopment of this antibiotic, to distil recommendations for future research and clinical efficacy.
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Affiliation(s)
- Ernest A Azzopardi
- Wound Biology Group, Tissue Engineering and Reparative Dentistry, School of Dentistry, Cardiff University, Heath Park, Cardiff, CF144XY, UK.
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17
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Zhang R, Zeng W, Meng X, Huang J, Wu W. Molecular dynamics simulations and 2D NOESY spectrum study on the different behaviors of glutathione disulfide in different solutions. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2012.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Molecular Dynamics Simulations and NMR Experimental Study of Oxidized Glutathione in Aqueous Solution. J SOLUTION CHEM 2012. [DOI: 10.1007/s10953-012-9835-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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19
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Zhang R, Wu W, Luo S. Different Behaviors of Glutathione in Aqueous and DMSO Solutions: Molecular Dynamics Simulation and NMR Experimental Study. J SOLUTION CHEM 2011. [DOI: 10.1007/s10953-011-9752-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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20
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Bhunia A, Bhattacharjya S. Mapping residue-specific contacts of polymyxin B with lipopolysaccharide by saturation transfer difference NMR: insights into outer-membrane disruption and endotoxin neutralization. Biopolymers 2011; 96:273-87. [PMID: 20683937 DOI: 10.1002/bip.21530] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
High-resolution interactions studies of molecules with lipopolysaccharide (LPS) or endotoxin are important for health, diseases and environment. LPS is the major constituent of the outer layer of the outer membrane of the gram-negative bacteria. LPS provides an efficient barrier against permeation of variety of compounds including antibacterial agents and antimicrobial peptides. In the intensive care units, LPS is known for the fatal septic shock syndromes. Because of LPS toxicity, high affinity LPS sensors are sought-after for the assessment of the quality of water and pharmaceutical products. Therefore, elucidation of binding epitopes of LPS interacting molecules would be vital for the development of antimicrobial, antiendotoxic molecules. Polymyxin B (PMB), an antibacterial cyclic lipo-peptide, is well known for its LPS sequestering and neutralizing activities. Here, we have used saturation transfer difference (STD) NMR methods for characterizing interactions of PMB with LPS from E. coli 0111:B4 and P. aeruginosa. The dissociation constants of the LPS-PMB complexes were obtained from concentration dependent STD studies. Further a detailed epitope mapping of PMB has been carried out in E. coli 0111:B4 LPS micelles. Experiments including one-dimensional 1H STD, two-dimensional 1H-1H STD-TOCSY and naturalabundance 13C-1H STD-HSQC, are performed to determine the site(s) of interactions of PMB with endotoxin at atomic resolution. Our studies reveal that the hydrophobic sidechains of PMB including a part of the N-terminus lipidic tail demonstrate close contacts with LPS. In contrast, cyclic backbone structure of PMB has the lowest STD effects suggesting a rather loose association with endotoxin.
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Affiliation(s)
- Anirban Bhunia
- Biomolecular NMR and Drug Discovery Laboratory, School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, Singapore 637551
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21
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Zhang R, Wu W. Studies on the structures and interactions of glutathione in aqueous solution by molecular dynamics simulations and NMR spectroscopy. J Mol Liq 2011. [DOI: 10.1016/j.molliq.2011.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Design, synthesis, and evaluation of a new fluorescent probe for measuring polymyxin-lipopolysaccharide binding interactions. Anal Biochem 2010; 409:273-83. [PMID: 21050838 DOI: 10.1016/j.ab.2010.10.033] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 10/27/2010] [Accepted: 10/27/2010] [Indexed: 11/24/2022]
Abstract
Fluorescence assays employing semisynthetic or commercial dansyl-polymyxin B have been widely employed to assess the affinity of polycations, including polymyxins, for bacterial cells and lipopolysaccharide (LPS). The five primary γ-amines on diaminobutyric acid residues of polymyxin B are potentially derivatized with dansyl-chloride. Mass spectrometric analysis of the commercial product revealed a complex mixture of di- or tetra-dansyl-substituted polymyxin B. We synthesized a mono-substituted fluorescent derivative, dansyl[Lys]¹polymyxin B₃. The affinity of polymyxin for purified gram-negative LPS and whole bacterial cells was investigated. The affinity of dansyl[Lys]¹polymyxin B₃ for LPS was comparable to polymyxin B and colistin, and considerably greater (K(d)<1 μM) than for whole cells (K(d)∼6-12μM). Isothermal titration calorimetric studies demonstrated exothermic enthalpically driven binding between both polymyxin B and dansyl[Lys]¹polymyxin B₃ to LPS, attributed to electrostatic interactions. The hydrophobic dansyl moiety imparted a greater entropic contribution to the dansyl[Lys]¹polymyxin B₃-LPS reaction. Molecular modeling revealed a loss of electrostatic contact within the dansyl[Lys]¹polymyxin B₃-LPS complex due to steric hindrance from the dansyl[Lys]¹ fluorophore; this corresponded with diminished antibacterial activity (MIC≥16μg/mL). Dansyl[Lys]¹polymyxin B₃ may prove useful as a screening tool for drug development.
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23
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Wallace SJ, Li J, Nation RL, Prankerd RJ, Velkov T, Boyd BJ. Self-assembly behavior of colistin and its prodrug colistin methanesulfonate: implications for solution stability and solubilization. J Phys Chem B 2010; 114:4836-40. [PMID: 20302384 DOI: 10.1021/jp100458x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Colistin is an amphiphilic antibiotic that has re-emerged into clinical use due to the increasing prevalence of difficult-to-treat Gram-negative infections. The existence of self-assembling colloids in solutions of colistin and its derivative prodrug, colistin methanesulfonate (CMS), was investigated. Colistin and CMS reduced the air-water interfacial tension, and dynamic light scattering (DLS) studies showed the existence of 2.07 +/- 0.3 nm aggregates above 1.5 mM for colistin and of 1.98 +/- 0.36 nm aggregates for CMS above 3.5 mM (mean +/- SD). Above the respective critical micelle concentrations (CMC) the solubility of azithromycin, a hydrophobic antibiotic, increased approximately linearly with increasing surfactant concentration (5:1 mol ratio colistin:azithromycin), suggestive of hydrophobic domains within the micellar cores. Rapid conversion of CMS to colistin occurred below the CMC (60% over 48 h), while conversion above the CMC was less than 1%. The formation of colistin and CMS micelles demonstrated in this study is the proposed mechanism for solubilization of azithromycin and the concentration-dependent stability of CMS.
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Affiliation(s)
- Stephanie J Wallace
- Facility for Anti-Infective Drug Development and Innovation, Monash Institute of Pharmaceutical Sciences, Parkville, Melbourne, Victoria 3052, Australia
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Naumenkova TV, Levtsova OV, Nikolaev IN, Shaitan KV. Comparative molecular dynamics study of the structural properties of melittin in water and trifluoroethanol/water. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910010057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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25
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Velkov T, Thompson PE, Nation RL, Li J. Structure--activity relationships of polymyxin antibiotics. J Med Chem 2010; 53:1898-916. [PMID: 19874036 DOI: 10.1021/jm900999h] [Citation(s) in RCA: 527] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Tony Velkov
- School of Medicine, Deakin University, Pigdons Road, Geelong 3217, Victoria, Australia.
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