1
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Billah MM, Ahmed M, Islam MZ, Yamazaki M. Processes and mechanisms underlying burst of giant unilamellar vesicles induced by antimicrobial peptides and compounds. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184330. [PMID: 38679311 DOI: 10.1016/j.bbamem.2024.184330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 04/05/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
To clarify the damage of lipid bilayer region in bacterial cell membrane caused by antimicrobial peptides (AMPs) and antimicrobial compounds (AMCs), their interactions with giant unilamellar vesicles (GUVs) of various lipid compositions have been examined. The findings revealed two main causes for the leakage: nanopore formation in the membrane and burst of GUVs. Although GUV burst has been explained previously based on the carpet model, the supporting evidence is limited. In this review, to better clarify the mechanism of GUV burst by AMPs, AMCs, and other membrane-active peptides, we described current knowledge of the conditions, characteristics, and detailed processes of GUV burst and the changes in the shape of the GUVs during burst. We identified several physical factors that affect GUV burst, such as membrane tension, electrostatic interaction, structural changes of GUV membrane such as membrane folding, and oil in the membrane. We also clarified one of the physical mechanisms underlying the instability of lipid bilayers that are associated with leakage in the carpet model. Based on these results, we propose a mechanism underlying some types of GUV burst induced by these substances: the growth of a nanopore to a micropore, resulting in GUV burst.
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Affiliation(s)
- Md Masum Billah
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan; Department of Physics, Jashore University and Science and Technology, Jashore 7408, Bangladesh
| | - Marzuk Ahmed
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan
| | - Md Zahidul Islam
- Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan
| | - Masahito Yamazaki
- Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan; Nanomaterials Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka 422-8529, Japan; Department of Physics, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
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2
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Ji F, Tian G, Shang D, Jiang F. Antimicrobial peptide 2K4L disrupts the membrane of multidrug-resistant Acinetobacter baumannii and protects mice against sepsis. Front Microbiol 2023; 14:1258469. [PMID: 37942076 PMCID: PMC10628664 DOI: 10.3389/fmicb.2023.1258469] [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: 07/31/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Antimicrobial peptides represent a promising therapeutic alternative for the treatment of antibiotic-resistant bacterial infections. 2K4L is a rationally-designed analog of a short peptide temporin-1CEc, a natural peptide isolated and purified from the skin secretions of the Chinese brown frog Rana chensinensis by substituting amino acid residues. 2K4L adopt an α-helical confirm in a membrane-mimetic environment and displayed an improved and broad-spectrum antibacterial activity against sensitive and multidrug-resistant Gram-negative and Gram-positive bacterial strains. Here, the action mechanism of 2K4L on multidrug resistant Acinetobacter baumannii (MRAB) and protection on MRAB-infected mice was investigated. The results demonstrated high bactericidal activity of 2K4L against both a multidrug resistant A. baumannii 0227 strain (MRAB 0227) and a sensitive A. baumannii strain (AB 22934), indicating a potential therapeutic advantage of this peptide. Strong positively-charged residues significantly promoted the electrostatic interaction on 2K4L with lipopolysaccharides (LPS) of the bacterial outer membrane. High hydrophobicity and an α-helical confirm endowed 2K4L remarkably increase the permeability of A. baumannii cytoplasmic membrane by depolarization of membrane potential and disruption of membrane integration, as well as leakage of fluorescein from the liposomes. Additionally, 2K4L at low concentrations inhibited biofilm formation and degraded mature 1-day-old MRAB 0227 biofilms by reducing the expression of biofilm-related genes. In an invasive A. baumannii infection model, 2K4L enhanced the survival of sepsis mice and decreased the production of the proinflammatory cytokines downregulating the phosphorylation level of signaling protein in MAPK and NF-κB signaling pathways, indicating that 2K4L represents a novel therapeutic antibiotic candidate against invasive multidrug-resistant bacterial strain infections.
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Affiliation(s)
- Fangyu Ji
- School of Life Science, Liaoning Normal University, Dalian, China
| | - Guoxu Tian
- School of Life Science, Liaoning Normal University, Dalian, China
| | - Dejing Shang
- School of Life Science, Liaoning Normal University, Dalian, China
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Fengquan Jiang
- Department of Clinical Laboratory, The First Affiliated Hospital of Dalian Medical University, Dalian, China
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3
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Wynne KJ, Zolotarskaya O, Jarrell R, Wang C, Amin Y, Brunson K. Facile Modification of Medical-Grade Silicone for Antimicrobial Effectiveness and Biocompatibility: A Potential Therapeutic Strategy against Bacterial Biofilms. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46626-46638. [PMID: 37782835 DOI: 10.1021/acsami.3c08734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
A one-step modification of biomedical silicone tubing with N,N-dimethyltetradecylamine, C14, results in a composition designated WinGard-1 (WG-1, 1.1 wt % C14). A surface-active silicon-amine phase (SAP) is proposed to account for increased wettability and increased surface charge. To understand the mechanism of antimicrobial effectiveness, several procedures were employed to detect whether C14 leaching occurred. An immersion-growth (IG) test was developed that required knowing the bacterial Minimum Inhibitory Concentrations (MICs) and Minimum Biocidal Concentrations (MBCs). The C14 MIC and MBC for Gm- uropathogenic E. coli (UPEC), commonly associated with catheter-associated urinary tract infections (CAUTI), were 10 and 20 μg/mL, respectively. After prior immersion of WG-1 silicone segments in a growth medium from 1 to 28 d, the IG test for the medium showed normal growth for UPEC over 24 h, indicating that the concentration of C14 must be less than the MIC, 10 μg/mL. GC-MS and studies of the medium inside and outside a dialysis bag containing WG-1 silicone segments supported de minimis leaching. Consequently, a 5 log UPEC reduction (99.999% kill) in 24 h using the shake flask test (ASTM E2149) cannot be due to leaching and is ascribed to contact kill. Interestingly, although the MBC was greater than 100 μg/mL for Pseudomonas aeruginosa, WG-1 silicone affected an 80% reduction via a 24 h shake flask test. For other bacteria and Candida albicans, greater than 99.9% shake flask kill may be understood by proposing increased wettability and concentration of charge illustrated in the TOC. De minimis leaching places WG-1 silicone at an advantage over conventional anti-infectives that rely on leaching of an antibiotic or heavy metals such as silver. The facile process for preparation of WG-1 silicone combined with biocidal effectiveness comprises progress toward the goals of device designation from the FDA for WG-1 and clearance.
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Affiliation(s)
- Kenneth J Wynne
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
| | - Olga Zolotarskaya
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
| | - Rebecca Jarrell
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
| | - Chenyu Wang
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
| | - Youssef Amin
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
| | - Kennard Brunson
- Virginia Bio+Tech Park, WynnVision LLC, Suite 57 800 East Leigh Street Richmond, Virginia 23219-1551, United States
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4
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Affiliation(s)
- Phuong Pham
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
| | - Susan Oliver
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
| | - Cyrille Boyer
- Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine School of Chemical Engineering The University of New South Wales Sydney NSW 2052 Australia
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5
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Kumari M, Roy S, Jaiswal A, Kashyap HK. Anionic Lipid Clustering-Mediated Bactericidal Activity and Selective Toxicity of Quaternary Ammonium-Substituted Polycationic Pullulan against the Staphylococcus aureus Bacterial Membrane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:8065-8076. [PMID: 35731708 DOI: 10.1021/acs.langmuir.2c00871] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Non-amphiphilic polycations have recently been recognized to hold excellent antimicrobial potential with great mammalian cell compatibility. In a recent study, the excellent broad-spectrum bactericidal efficacy of a quaternary ammonium-substituted cationic pullulan (CP4) was demonstrated. Their selective toxicity and nominal probability to induce the acquisition of resistance among pathogens fulfill the fundamental requirements of new-generation antibacterials. However, there have been exiguous attempts in the literature to understand the antimicrobial activity of polycations against Gram-positive bacterial membranes. Here, for the first time, we have scrutinized the molecular level interactions of CP4 tetramers with a model Staphylococcus aureus membrane to understand their probable antibacterial function using molecular dynamics simulations. Our analysis reveals that the hydrophilic CP4 molecules are spontaneously adsorbed onto the membrane outer leaflet surface by virtue of strong electrostatic interactions and do not penetrate into the lipid tail hydrophobic region. This surface binding of CP4 is strengthened by the formation of anionic lipid-rich domains in their vicinity, causing lateral compositional heterogeneity. The major outcomes of the asymmetric accumulation of bulky polycationic CP4 on one leaflet are (i) anionic lipid segregation at the interaction site and (ii) a decrease in the cationic lipid acyl tail ordering and ease of water translocation across the lipid hydrophobic barrier. The membrane-CP4 interactions are strongly monitored by the ionic strength; a higher salt concentration weakens the binding of CP4 on the membrane surface. In addition, our study also substantiates the non-interacting behavior of CP4 oligomers with biomimetic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane, indicating their cell selectivity and specificity against pathogenic membranes.
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Affiliation(s)
- Monika Kumari
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Shounak Roy
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Mandi, Himachal Pradesh 175075, India
| | - Amit Jaiswal
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Mandi, Himachal Pradesh 175075, India
| | - Hemant K Kashyap
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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6
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Unveiling Putative Functions of Mucus Proteins and Their Tryptic Peptides in Seven Gastropod Species Using Comparative Proteomics and Machine Learning-Based Bioinformatics Predictions. Molecules 2021; 26:molecules26113475. [PMID: 34200462 PMCID: PMC8201360 DOI: 10.3390/molecules26113475] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 12/25/2022] Open
Abstract
Gastropods are among the most diverse animals. Gastropod mucus contains several glycoproteins and peptides that vary by species and habitat. Some bioactive peptides from gastropod mucus were identified only in a few species. Therefore, using biochemical, mass spectrometric, and bioinformatics approaches, this study aimed to comprehensively identify putative bioactive peptides from the mucus proteomes of seven commonly found or commercially valuable gastropods. The mucus was collected in triplicate samples, and the proteins were separated by 1D-SDS-PAGE before tryptic digestion and peptide identification by nano LC-MS/MS. The mucus peptides were subsequently compared with R scripts. A total of 2818 different peptides constituting 1634 proteins from the mucus samples were identified, and 1218 of these peptides (43%) were core peptides found in the mucus of all examined species. Clustering and correspondence analyses of 1600 variable peptides showed unique mucous peptide patterns for each species. The high-throughput k-nearest neighbor and random forest-based prediction programs were developed with more than 95% averaged accuracy and could identify 11 functional categories of putative bioactive peptides and 268 peptides (9.5%) with at least five to seven bioactive properties. Antihypertensive, drug-delivering, and antiparasitic peptides were predominant. These peptides provide an understanding of gastropod mucus, and the putative bioactive peptides are expected to be experimentally validated for further medical, pharmaceutical, and cosmetic applications.
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7
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Ma L, Luo Y, Ma YH, Lu X. Interaction between Antimicrobial Peptide CM15 and a Model Cell Membrane Affected by CM15 Terminal Amidation and the Membrane Phase State. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1613-1621. [PMID: 33464910 DOI: 10.1021/acs.langmuir.0c03498] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Antimicrobial peptides (AMPs) have been proposed as an effective class of antimicrobial agents against microorganisms. In this work, the interaction between an antimicrobial peptide, CM15, and a negatively charged phospholipid bilayer, DPPG, was studied via sum frequency generation (SFG) vibrational spectroscopy. Two structurally correlated characteristic variables were introduced to reveal the interaction mechanism/efficiency, i.e. C-terminal amidation and temperature variation (∼20 °C, room temperature, and ∼35 °C, close to human body temperature). Experimental results indicated that owing to the increased positive charge, C-terminal amidation resulted in rapid adsorption onto the bilayer surface and efficient disruption of the outer layer, exhibiting less ordered insertion orientation. The elevated temperature (from ∼20 °C to ∼35 °C) promoted the penetration of both the outer and inner leaflets by the peptides and finally led to the disruption of the whole bilayer owing to the enhanced fluidity of the bilayer. From the perspective of the interaction mechanism, this experimental study provides two practical cues to understand the disruption process of the negatively charged model biomembranes, which can lay the structural foundation for designing and developing high-efficiency antimicrobial peptides.
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Affiliation(s)
- Liang Ma
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, Jiangsu Province, P. R. China
| | - Yongsheng Luo
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, Jiangsu Province, P. R. China
| | - Yong-Hao Ma
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, Jiangsu Province, P. R. China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science & Medical Engineering, Southeast University, Nanjing, 210096, Jiangsu Province, P. R. China
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8
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Phuong PT, Oliver S, He J, Wong EHH, Mathers RT, Boyer C. Effect of Hydrophobic Groups on Antimicrobial and Hemolytic Activity: Developing a Predictive Tool for Ternary Antimicrobial Polymers. Biomacromolecules 2020; 21:5241-5255. [DOI: 10.1021/acs.biomac.0c01320] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Pham Thu Phuong
- Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Susan Oliver
- Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Junchen He
- Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Edgar H. H. Wong
- Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Robert T. Mathers
- Department of Chemistry, Penn State University, New Kensington, Pennsylvania 15068, United States
| | - Cyrille Boyer
- Australian Centre for NanoMedicine, School of Chemical Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
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9
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Kopec W, Żak A, Jamróz D, Nakahata R, Yusa SI, Gapsys V, Kepczynski M. Polycation-Anionic Lipid Membrane Interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12435-12450. [PMID: 33058724 PMCID: PMC7594277 DOI: 10.1021/acs.langmuir.0c01062] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Natural or synthetic polycations are used as biocides or as drug/gene carriers. Understanding the interactions between these macromolecules and cell membranes at the molecular level is therefore of great importance for the design of effective polymer biocides or biocompatible polycation-based delivery systems. Until now, details of the processes at the interface between polycations and biological systems have not been fully recognized. In this study, we consider the effect of strong polycations with quaternary ammonium groups on the properties of anionic lipid membranes that we use as a model system for protein-free cell membranes. For this purpose, we employed experimental measurements and atomic-scale molecular dynamics (MD) simulations. MD simulations reveal that the polycations are strongly hydrated in the aqueous phase and do not lose the water shell after adsorption at the bilayer surface. As a result of strong hydration, the polymer chains reside at the phospholipid headgroup and do not penetrate to the acyl chain region. The polycation adsorption involves the formation of anionic lipid-rich domains, and the density of anionic lipids in these domains depends on the length of the polycation chain. We observed the accumulation of anionic lipids only in the leaflet interacting with the polymer, which leads to the formation of compositionally asymmetric domains. Asymmetric adsorption of the polycation on only one leaflet of the anionic membrane strongly affects the membrane properties in the polycation-membrane contact areas: (i) anionic lipid accumulates in the region near the adsorbed polymer, (ii) acyl chain ordering and lipid packing are reduced, which results in a decrease in the thickness of the bilayer, and (iii) polycation-anionic membrane interactions are strongly influenced by the presence and concentration of salt. Our results provide an atomic-scale description of the interactions of polycations with anionic lipid bilayers and are fully supported by the experimental data. The outcomes are important for understanding the correlation of the structure of polycations with their activity on biomembranes.
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Affiliation(s)
- Wojciech Kopec
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
- Computational
Biomolecular Dynamics Group, Max Planck
Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Agata Żak
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Dorota Jamróz
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Rina Nakahata
- Department
of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Shin-ichi Yusa
- Department
of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Vytautas Gapsys
- Computational
Biomolecular Dynamics Group, Max Planck
Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Mariusz Kepczynski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
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10
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Yang S, Dong Y, Aweya JJ, Xie T, Zeng B, Zhang Y, Liu GM. Antimicrobial activity and acting mechanism of Tegillarca granosa hemoglobin-derived peptide (TGH1) against Vibrio parahaemolyticus. Microb Pathog 2020; 147:104302. [DOI: 10.1016/j.micpath.2020.104302] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 01/12/2023]
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11
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Chen C, Li G, Cui X, Chen J, Yu Q, Zong C, Zhao Y, Xu M, Zhou S, Xu H. Mechanistic Investigation of a Self-Assembling Peptide against Escherichia coli. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9800-9809. [PMID: 32787117 DOI: 10.1021/acs.langmuir.0c01311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Because of their distinctive mode of action in targeting bacterial cell membranes, antimicrobial peptides (AMPs) are increasingly regarded as a potential candidate for the development of novel antibiotics to combat the wide spread of bacterial resistance. To date, understanding of the exact molecular process by which AMPs act on the real bacterial envelope remains challenging. Simultaneously, the aggregated state of AMPs upon interaction with bacterial envelopes is still elusive. Previously, we have demonstrated that the potent antibacterial activity of a designed surfactant-like peptide Ac-A9K-NH2 benefited greatly from its high self-assembling ability and appropriate self-assembled morphologies and sizes. By using high-resolution atomic force microscopy, we here not only follow the variations of the Escherichia coli cell envelope in the presence of Ac-A9K-NH2 but also characterize the peptide aggregates on the bacterial surface as well as on the substrate surface. The results, together with those from fluorescence, zeta potential, circular dichroism, and scanning electron microscopy measurements, indicate that both the positively charged peptide monomers and self-assembled nanostructures can directly act on the negatively charged bacterial surface, followed by their insertion into the bacterial membrane, the formation of surface nanopores, and membrane lysis. The mechanism of Ac-A9K-NH2 against E. coli is thus consistent with the detergent-like mode of action. This work enhances our mechanistic understanding of the antibacterial behaviors of self-assembling peptides that will be valuable in exploring their biomedical applications.
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Affiliation(s)
- Cuixia Chen
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Gongrang Li
- Drilling Technology Research Institute, Sinopec Shengli Oilfield Service Corporation, Dongying 257000, China
| | - Xuejing Cui
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Jiaxi Chen
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Qizhi Yu
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Cheng Zong
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Yurong Zhao
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Minglu Xu
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Shasha Zhou
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Hai Xu
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
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12
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Hammond K, Ryadnov MG, Hoogenboom BW. Atomic force microscopy to elucidate how peptides disrupt membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183447. [PMID: 32835656 DOI: 10.1016/j.bbamem.2020.183447] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/30/2020] [Accepted: 08/13/2020] [Indexed: 12/24/2022]
Abstract
Atomic force microscopy is an increasingly attractive tool to study how peptides disrupt membranes. Often performed on reconstituted lipid bilayers, it provides access to time and length scales that allow dynamic investigations with nanometre resolution. Over the last decade, AFM studies have enabled visualisation of membrane disruption mechanisms by antimicrobial or host defence peptides, including peptides that target malignant cells and biofilms. Moreover, the emergence of high-speed modalities of the technique broadens the scope of investigations to antimicrobial kinetics as well as the imaging of peptide action on live cells in real time. This review describes how methodological advances in AFM facilitate new insights into membrane disruption mechanisms.
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Affiliation(s)
- Katharine Hammond
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK; London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; Department of Physics & Astronomy, University College London, London WC1E 6BT, UK.
| | - Maxim G Ryadnov
- National Physical Laboratory, Hampton Road, Teddington TW11 0LW, UK; Department of Physics, King's College London, Strand Lane, London WC2R 2LS, UK.
| | - Bart W Hoogenboom
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK; Department of Physics & Astronomy, University College London, London WC1E 6BT, UK.
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13
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Wang C, Zolotarskaya O, Ashraf KM, Wen X, Ohman DE, Wynne KJ. Surface Characterization, Antimicrobial Effectiveness, and Human Cell Response for a Biomedical Grade Polyurethane Blended with a Mixed Soft Block PTMO-Quat/PEG Copolyoxetane Polyurethane. ACS APPLIED MATERIALS & INTERFACES 2019; 11:20699-20714. [PMID: 31117452 DOI: 10.1021/acsami.9b04697] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Infection is a serious medical complication associated with health care environments. Despite advances, the 5-10% incidence of infections for hospital patients is well documented. Sources of pathogenic organisms include medical devices such as catheters and endotracheal tubes. Offering guidance for curbing the spread of such infections, a model antimicrobial coating is described herein that kills bacteria on contact but is compatible with human cells. To achieve these characteristics, a novel blend of a conventional biomedical grade polyurethane (Tecoflex) with mixed soft block polyurethane is described. The functional polyurethane (UP-C12-50-T) has a copolyoxetane soft block P-C12-50 with quaternary ammonium (C12) and PEG-like side chains and a conventional poly(tetramethylene oxide) (PTMO, T) soft block. DSC and DMA data point to limited miscibility of UP-C12-50-T with Tecoflex. The blend of Tecoflex with 10 wt % UP-C12-50-T designated UP-C12-50-T-10 radically changed surface properties. Evidence for surface concentration of the P-C12-50 soft block was obtained by atomic force microscopy (AFM), dynamic contact angles (DCAs), zeta potentials (ζ), and X-ray photoelectron spectroscopy (XPS). The antimicrobial effectiveness of the blend coatings was established by the ASTM E2149 "shake flask" test for challenges of E. coli and a methicillin resistant strain of S. epidermidis. Cytocompatibility was demonstrated with an in vitro test designed for direct contact (ISO 10993-5). Growth of human mesenchymal stem cells (MSCs) beside and under UP-C12-50-T-10 indicated remarkable biocompatibility for a composition that is also strongly antimicrobial. Overall, the results point to a model coating with a level of P-C12-50 that combines high antimicrobial effectiveness and low toxicity to human cells.
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Affiliation(s)
- Chenyu Wang
- Department of Chemical and Life Science Engineering , Virginia Commonwealth University , Biotech8, 737 North Fifth Street , Richmond , Virginia 23219 , United States
| | - Olga Zolotarskaya
- Department of Chemical and Life Science Engineering , Virginia Commonwealth University , Biotech8, 737 North Fifth Street , Richmond , Virginia 23219 , United States
| | - Kayesh M Ashraf
- Department of Chemical and Life Science Engineering , Virginia Commonwealth University , Biotech8, 737 North Fifth Street , Richmond , Virginia 23219 , United States
| | - Xuejun Wen
- Department of Chemical and Life Science Engineering , Virginia Commonwealth University , Biotech8, 737 North Fifth Street , Richmond , Virginia 23219 , United States
- Institute for Engineering and Medicine, Department of Chemical and Life Science Engineering , Virginia Commonwealth University , 601 West Main Street, Room # 403 , Richmond , Virginia 23284-3028 , United States
| | - Dennis E Ohman
- Department of Microbiology and Immunology , VCU School of Medicine , 1101 East Marshall Street , Richmond , Virginia 23298 , United States
- McGuire Veterans Affairs Medical Center , Richmond , Virginia 23249 , United States
| | - Kenneth J Wynne
- Department of Chemical and Life Science Engineering , Virginia Commonwealth University , Biotech8, 737 North Fifth Street , Richmond , Virginia 23219 , United States
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14
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Fukushima K, Kishi K, Saito K, Takakuwa K, Hakozaki S, Yano S. Modulating bioactivities of primary ammonium-tagged antimicrobial aliphatic polycarbonates by varying length, sequence and hydrophobic side chain structure. Biomater Sci 2019; 7:2288-2296. [DOI: 10.1039/c9bm00440h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A highly antimicrobial, biocompatible, and fast biodegradable polycarbonate has been developed by incorporating primary ammonium and monoether side chains.
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Affiliation(s)
- Kazuki Fukushima
- Graduate School of Organic Materials Science
- Yamagata University
- Yonezawa
- Japan
| | - Kohei Kishi
- Graduate School of Organic Materials Science
- Yamagata University
- Yonezawa
- Japan
| | - Keita Saito
- Graduate School of Organic Materials Science
- Yamagata University
- Yonezawa
- Japan
| | - Kazuki Takakuwa
- Graduate School of Organic Materials Science
- Yamagata University
- Yonezawa
- Japan
| | - Shunta Hakozaki
- Graduate School of Organic Materials Science
- Yamagata University
- Yonezawa
- Japan
| | - Shigekazu Yano
- Graduate School of Science and Engineering
- Yamagata University
- Japan
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15
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Abstract
Antimicrobial peptides (AMPs) are one of the most promising alternatives to conventional antibiotics. Atomic force microscopy (AFM), as imaging and force spectroscopy tool, has been applied to study their mechanism of action and development. Here, we describe different methods to be applied in the study of AMP effects on bacteria, either by imaging or by force spectroscopy studies, essential to underlie their action and to identify possibly outcomes of the same.
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Affiliation(s)
- Marco M Domingues
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
| | - Mário R Felício
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal.
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16
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Wang L, Dong C, Li X, Han W, Su X. Anticancer potential of bioactive peptides from animal sources (Review). Oncol Rep 2017; 38:637-651. [PMID: 28677775 DOI: 10.3892/or.2017.5778] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 04/10/2017] [Indexed: 11/06/2022] Open
Abstract
Cancer is the most common cause of human death worldwide. Conventional anticancer therapies, including chemotherapy and radiation, are associated with severe side effects and toxicities as well as low specificity. Peptides are rapidly being developed as potential anticancer agents that specifically target cancer cells and are less toxic to normal tissues, thus making them a better alternative for the prevention and management of cancer. Recent research has focused on anticancer peptides from natural animal sources, such as terrestrial mammals, marine animals, amphibians, and animal venoms. However, the mode of action by which bioactive peptides inhibit the proliferation of cancer cells remains unclear. In this review, we present the animal sources from which bioactive peptides with anticancer activity are derived and discuss multiple proposed mechanisms by which these peptides exert cytotoxic effects against cancer cells.
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Affiliation(s)
- Linghong Wang
- Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Huimin, Hohhot, Inner Mongolia 010050, P.R. China
| | - Chao Dong
- College of Basic Medicine of Inner Mongolia Medical University, Huimin, Hohhot, Inner Mongolia 010050, P.R. China
| | - Xian Li
- Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Huimin, Hohhot, Inner Mongolia 010050, P.R. China
| | - Wenyan Han
- Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Huimin, Hohhot, Inner Mongolia 010050, P.R. China
| | - Xiulan Su
- Clinical Medicine Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Huimin, Hohhot, Inner Mongolia 010050, P.R. China
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17
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Nair SS, Zolotarskaya OY, Beckwith MJ, Ohman DE, Wynne KJ. A Polycation Antimicrobial Peptide Mimic without Resistance Buildup against Propionibacterium Acnes. Macromol Biosci 2017; 17. [PMID: 28605136 DOI: 10.1002/mabi.201700090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/08/2017] [Indexed: 11/09/2022]
Abstract
A preliminary study is reported for a polycation antimicrobial peptide (AMP) mimic against Propionibacterium acnes, which is associated with acne vulgaris, a common skin condition. Antibiotics are commonly used against P. acnes but buildup of resistance is well-known. Worse, antibiotic regimens build up resistance for more sensitive bacteria such as Staphylococcus epidermidis. The polycation AMP mimic C12-50, 1, is chosen for the present study as it has been previously shown to have high antimicrobial effectiveness. This study reports that C12-50 is active against P. acnes (strain ATCC 6919) with a minimum inhibitory concentration (MIC) of 6.3 µg mL-1 . To monitor resistance build-up ten passages are conducted with C12-50 against P. acnes. The MIC remains constant with no resistance buildup. Parallel studies with erythromycin confirm previously reported resistance buildup. The results point to a promising pathway to applications for polycation AMP mimics against P. acnes.
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Affiliation(s)
- Sithara S Nair
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Olga Y Zolotarskaya
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Matthew J Beckwith
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23219, USA
| | - Dennis E Ohman
- Department of Microbiology and Immunology, VCU School of Medicine, 1101 East Marshall Street, Richmond, VA, 23298, USA.,McGuire Veterans Affairs Medical Center, Richmond, VA, 23249, USA
| | - Kenneth J Wynne
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, 23219, USA
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18
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19
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Takahashi H, Caputo GA, Vemparala S, Kuroda K. Synthetic Random Copolymers as a Molecular Platform To Mimic Host-Defense Antimicrobial Peptides. Bioconjug Chem 2017; 28:1340-1350. [PMID: 28379682 DOI: 10.1021/acs.bioconjchem.7b00114] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Synthetic polymers have been used as a molecular platform to develop host-defense antimicrobial peptide (AMP) mimetics which are effective in killing drug-resistant bacteria. In this topical review, we will discuss the AMP-mimetic design and chemical optimization strategies as well as the biological and biophysical implications of AMP mimicry by synthetic polymers. Traditionally, synthetic polymers have been used as a chemical means to replicate the chemical functionalities and physicochemical properties of AMPs (e.g., cationic charge, hydrophobicity) to recapitulate their mode of action. However, we propose a new perception that AMP-mimetic polymers are an inherently bioactive platform as whole molecules, which mimic more than the side chain functionalities of AMPs. The tunable nature and chemical simplicity of synthetic random polymers facilitate the development of potent, cost-effective, broad-spectrum antimicrobials. The polymer-based approach offers the potential for many antimicrobial applications to be used directly in solution or attached to surfaces to fight against drug-resistant bacteria.
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Affiliation(s)
- Haruko Takahashi
- Center for International Research on Integrative Biomedical Systems, Institute of Industrial Science, The University of Tokyo , Tokyo, 153-8505, Japan
| | | | - Satyavani Vemparala
- The Institute of Mathematical Sciences , C.I.T. Campus, Taramani, Chennai, 600113, India
| | - Kenichi Kuroda
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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20
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Troiano JM, McGeachy AC, Olenick LL, Fang D, Liang D, Hong J, Kuech TR, Caudill ER, Pedersen JA, Cui Q, Geiger FM. Quantifying the Electrostatics of Polycation–Lipid Bilayer Interactions. J Am Chem Soc 2017; 139:5808-5816. [DOI: 10.1021/jacs.6b12887] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Julianne M. Troiano
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States,
| | - Alicia C. McGeachy
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States,
| | - Laura L. Olenick
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States,
| | - Dong Fang
- Department
of Chemistry, University of Wisconsin, 680 North Park Street, Madison, Wisconsin 53706, United States, and
| | - Dongyue Liang
- Department
of Chemistry, University of Wisconsin, 680 North Park Street, Madison, Wisconsin 53706, United States, and
| | - Jiewei Hong
- Department
of Chemistry, University of Wisconsin, 680 North Park Street, Madison, Wisconsin 53706, United States, and
| | - Thomas R. Kuech
- Environmental
Chemistry and Technology Program, University of Wisconsin, 1415 Engineering
Drive, Madison, Wisconsin 53706, United States
| | - Emily R. Caudill
- Environmental
Chemistry and Technology Program, University of Wisconsin, 1415 Engineering
Drive, Madison, Wisconsin 53706, United States
| | - Joel A. Pedersen
- Department
of Chemistry, University of Wisconsin, 680 North Park Street, Madison, Wisconsin 53706, United States, and
- Environmental
Chemistry and Technology Program, University of Wisconsin, 1415 Engineering
Drive, Madison, Wisconsin 53706, United States
| | - Qiang Cui
- Department
of Chemistry, University of Wisconsin, 680 North Park Street, Madison, Wisconsin 53706, United States, and
| | - Franz M. Geiger
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States,
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21
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Takahashi H, Nadres ET, Kuroda K. Cationic Amphiphilic Polymers with Antimicrobial Activity for Oral Care Applications: Eradication of S. mutans Biofilm. Biomacromolecules 2016; 18:257-265. [PMID: 27992189 DOI: 10.1021/acs.biomac.6b01598] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The antibacterial and antibiofilm activities of cationic amphiphilic methacrylate polymers against cariogenic bacterium S. mutans were investigated. Cationic homopolymer PE0 and copolymer PE31 containing 31 mol % of ethyl methacrylate were synthesized by reversible addition-fragmentation chain transfer polymerization. These polymers displayed bactericidal activity toward S. mutans and prevented biofilm formation by killing the planktonic bacteria. At a concentration of 1000 μg/mL when incubated for 2 h the polymers reduced >80% of biofilm biomass. When the polymer assay solution with the biofilm was vigorously mixed using a pipet for 30 s, >50% of biofilm mass was removed at a polymer concentration of 250 μg/mL. Chlorhexidine and a cationic surfactant failed to reduce the biofilm mass at the same concentration. PE0 was the most effective in removing biofilm and did not show any significant cytotoxicity to human gingival fibroblast and periodontal ligament stem cells when incubated for 10 min.
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Affiliation(s)
- Haruko Takahashi
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Enrico T Nadres
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Kenichi Kuroda
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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22
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Affiliation(s)
- Wei Ren
- Institute of Materials Research and Engineering; A*STAR, 2 Fusionopolis Way, Innovis #08-03 138634 Singapore
| | - Weiren Cheng
- Institute of Materials Research and Engineering; A*STAR, 2 Fusionopolis Way, Innovis #08-03 138634 Singapore
| | - Guan Wang
- Institute of Materials Research and Engineering; A*STAR, 2 Fusionopolis Way, Innovis #08-03 138634 Singapore
| | - Ye Liu
- Institute of Materials Research and Engineering; A*STAR, 2 Fusionopolis Way, Innovis #08-03 138634 Singapore
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23
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Vasilchenko AS, Rogozhin EA, Vasilchenko AV, Kartashova OL, Sycheva MV. Novel haemoglobin-derived antimicrobial peptides from chicken (Gallus gallus) blood: purification, structural aspects and biological activity. J Appl Microbiol 2016; 121:1546-1557. [PMID: 27583823 DOI: 10.1111/jam.13286] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/25/2016] [Accepted: 08/25/2016] [Indexed: 11/28/2022]
Abstract
AIM To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. METHODS AND RESULTS Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. CONCLUSION In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. SIGNIFICANCE AND IMPACT OF THE STUDY The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents.
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Affiliation(s)
- A S Vasilchenko
- Institute of Cellular and Intracellular Symbiosis, RAS, Orenburg, Russia
| | - E A Rogozhin
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Gause Institute of New Antibiotics, Moscow, Russia
| | | | - O L Kartashova
- Institute of Cellular and Intracellular Symbiosis, RAS, Orenburg, Russia
| | - M V Sycheva
- Institute of Cellular and Intracellular Symbiosis, RAS, Orenburg, Russia.,Orenburg State Agrarian University, Orenburg, Russia
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24
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Wang C, Ehrhardt CJ, Yadavalli VK. Nanoscale imaging and hydrophobicity mapping of the antimicrobial effect of copper on bacterial surfaces. Micron 2016; 88:16-23. [PMID: 27258941 DOI: 10.1016/j.micron.2016.05.005] [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] [Received: 03/07/2016] [Revised: 05/05/2016] [Accepted: 05/12/2016] [Indexed: 12/21/2022]
Abstract
Copper has a long historical role in the arena of materials with antimicrobial properties. Various forms of copper ranging from surfaces to impregnation in textiles and particles, have attracted considerable interest owing to their versatility, potency, chemical stability, and low cost. However, the effects and mechanisms of their antimicrobial action is still unclear. In this study, the effect of copper particles on Escherichia coli was studied at the nanoscale using atomic force microscopy (AFM). Time-lapse AFM images at the single cell level show the morphological changes on live E. coli during antimicrobial treatment, in which for the first time, this process was followed in situ on the same cell over time. AFM-based hydrophobicity mapping further showed that incubating cells with Cu decreased the surface hydrophobicity with an increase of incubation time. Specifically, we are able to visualize both morphology and physico-chemical nature of the bacterial cell surface change in response to copper treatment, leading to the membrane damage and cytoplasm leakage. Overall, the time-lapse AFM imaging combined with hydrophobicity mapping approach presented here provides spatio-temporal insight into the antimicrobial mechanisms of copper at the single cell level, and can be applied to design of better metallic antimicrobial materials as well as investigate different microorganisms.
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Affiliation(s)
- Congzhou Wang
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | | | - Vamsi K Yadavalli
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA.
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