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Omardien S, Brul S, Zaat SAJ. Antimicrobial Activity of Cationic Antimicrobial Peptides against Gram-Positives: Current Progress Made in Understanding the Mode of Action and the Response of Bacteria. Front Cell Dev Biol 2016; 4:111. [PMID: 27790614 PMCID: PMC5063857 DOI: 10.3389/fcell.2016.00111] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Accepted: 09/21/2016] [Indexed: 01/11/2023] Open
Abstract
Antimicrobial peptides (AMPs) have been proposed as a novel class of antimicrobials that could aid the fight against antibiotic resistant bacteria. The mode of action of AMPs as acting on the bacterial cytoplasmic membrane has often been presented as an enigma and there are doubts whether the membrane is the sole target of AMPs. Progress has been made in clarifying the possible targets of these peptides, which is reported in this review with as focus gram-positive vegetative cells and spores. Numerical estimates are discussed to evaluate the possibility that targets, other than the membrane, could play a role in susceptibility to AMPs. Concerns about possible resistance that bacteria might develop to AMPs are addressed. Proteomics, transcriptomics, and other molecular techniques are reviewed in the context of explaining the response of bacteria to the presence of AMPs and to predict what resistance strategies might be. Emergent mechanisms are cell envelope stress responses as well as enzymes able to degrade and/or specifically bind (and thus inactivate) AMPs. Further studies are needed to address the broadness of the AMP resistance and stress responses observed.
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Affiliation(s)
- Soraya Omardien
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Stanley Brul
- Department of Molecular Biology and Microbial Food Safety, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Sebastian A J Zaat
- Department of Medical Microbiology, Center for Infection and Immunity Amsterdam, Academic Medical Center, University of Amsterdam Amsterdam, Netherlands
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102
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Nadres ET, Takahashi H, Kuroda K. Radical-medicated end-group transformation of amphiphilic methacrylate random copolymers for modulation of antimicrobial and hemolytic activities. ACTA ACUST UNITED AC 2016. [DOI: 10.1002/pola.28384] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Enrico T. Nadres
- Department of Biologic and Materials Sciences, School of Dentistry; University of Michigan; Ann Arbor Michigan 48109
| | - Haruko Takahashi
- Department of Biologic and Materials Sciences, School of Dentistry; University of Michigan; Ann Arbor Michigan 48109
| | - Kenichi Kuroda
- Department of Biologic and Materials Sciences, School of Dentistry; University of Michigan; Ann Arbor Michigan 48109
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103
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Muthukumarasamyvel T, Baskar R, Chandirasekar S, Umamaheswari K, Rajendiran N. Hierarchical Self-Assembly of Bile-Acid-Derived Dicationic Amphiphiles and Their Toxicity Assessment on Microbial and Mammalian Systems. ACS APPLIED MATERIALS & INTERFACES 2016; 8:25111-26. [PMID: 27584681 DOI: 10.1021/acsami.6b08018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
A thiol-yne click chemistry approach was adopted for the first time to prepare highly water-soluble bile acid derived dicationic amphiphiles. The synthesized amphiphiles dicationic cysteamine conjugated cholic acid (DCaC), dicationic cysteamine conjugated deoxycholic acid (DCaDC), and dicationic cysteamine conjugated lithocholic acid (DCaLC) exhibited hierarchically self-assembled microstructures at various concentrations in an aqueous medium. Interestingly at below critical micellar concentration (CMC) the amphiphiles showed distinct fractal patterns such as fractal grass, microdendrites and fern leaf like fractals for DCaC, DCaDC and DCaLC respectively. The fractal dimension (Df) analysis indicated that the formation of fractal like aggregates is a diffusion limited aggregation (DLA) process. The preliminary aggregation studies such as determination of CMC, fluorescence quenching, wettability and contact angle measurements were elaborately investigated. The morphology of the aggregates were analyzed by SEM and OPM techniques. Further, we demonstrated the antimicrobial and hemolytic activity for the cationic amphiphiles. DCaC had potent antimicrobial activity and showed no toxicity on human RBCs indicating that DCaC could be used in biomedical applications, in addition to their industrial and laboratory applications such as detergency, surface cleaning, and disinfection agent.
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Affiliation(s)
| | - Raju Baskar
- Department of Biotechnology, University of Madras , Guindy Campus, Chennai 600025, Tamil Nadu, India
| | - Shanmugam Chandirasekar
- Department of Polymer Science, University of Madras , Guindy Campus, Chennai 600025, Tamil Nadu, India
| | | | - Nagappan Rajendiran
- Department of Polymer Science, University of Madras , Guindy Campus, Chennai 600025, Tamil Nadu, India
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104
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Ahn M, Gunasekaran P, Rajasekaran G, Kim EY, Lee SJ, Bang G, Cho K, Hyun JK, Lee HJ, Jeon YH, Kim NH, Ryu EK, Shin SY, Bang JK. Pyrazole derived ultra-short antimicrobial peptidomimetics with potent anti-biofilm activity. Eur J Med Chem 2016; 125:551-564. [PMID: 27718471 DOI: 10.1016/j.ejmech.2016.09.071] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/20/2016] [Accepted: 09/21/2016] [Indexed: 12/18/2022]
Abstract
In this study, we report on the first chemical synthesis of ultra-short pyrazole-arginine based antimicrobial peptidomimetics derived from the newly synthesized N-alkyl/aryl pyrazole amino acids. Through the systematic tuning of hydrophobicity, charge, and peptide length, we identified the shortest peptide Py11 with the most potent antimicrobial activity. Py11 displayed greater antimicrobial activity against antibiotic-resistant bacteria, including MRSA, MDRPA, and VREF, which was approximately 2-4 times higher than that of melittin. Besides its higher selectivity (therapeutic index) toward bacterial cells than LL-37, Py11 showed highly increased proteolytic stability against trypsin digestion and maintained its antimicrobial activity in the presence of physiological salts. Interestingly, Py11 exhibited higher anti-biofilm activity against MDRPA compared to LL-37. The results from fluorescence spectroscopy and transmission electron microscopy (TEM) suggested that Py11 kills bacterial cells possibly by integrity disruption damaging the cell membrane, leading to the cytosol leakage and eventual cell lysis. Furthermore, Py11 displayed significant anti-inflammatory (endotoxin-neutralizing) activity by inhibiting LPS-induced production of nitric oxide (NO) and TNF-α. Collectively, our results suggest that Py11 may serve as a model compound for the design of antimicrobial and antisepsis agents.
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Affiliation(s)
- Mija Ahn
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, 363-883, Republic of Korea
| | - Pethaiah Gunasekaran
- Molecular Embryology Laboratory, Department of Animal Sciences, Chungbuk National University, Chung-Buk, 361-763, Republic of Korea
| | - Ganesan Rajasekaran
- Department of Medical Science, Graduate School and Department of Cellular & Molecular Medicine, School of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea
| | - Eun Young Kim
- Department of Medical Science, Graduate School and Department of Cellular & Molecular Medicine, School of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea
| | - Soo-Jae Lee
- College of Pharmacy, Chungbuk National University, Chungbuk, 361-763, Republic of Korea
| | - Geul Bang
- Biomedical Omics Group, Korea Basic Science Institute, Ochang, Chung-Buk, 363-883, Republic of Korea
| | - Kun Cho
- Biomedical Omics Group, Korea Basic Science Institute, Ochang, Chung-Buk, 363-883, Republic of Korea
| | - Jae-Kyung Hyun
- Division of Electron Microscopic Research, Korea Basic Science Institute, 113 Gwahakro, Daejeon, 305-333, Republic of Korea
| | - Hyun-Ju Lee
- Division of Electron Microscopic Research, Korea Basic Science Institute, 113 Gwahakro, Daejeon, 305-333, Republic of Korea; Department of Chemistry, Chungnam National University, Daejeon, 305-764, Republic of Korea
| | - Young Ho Jeon
- College of Pharmacy, Korea University, 2511 Sejong-Ro, Sejong, 30019, Republic of Korea
| | - Nam-Hyung Kim
- Molecular Embryology Laboratory, Department of Animal Sciences, Chungbuk National University, Chung-Buk, 361-763, Republic of Korea
| | - Eun Kyoung Ryu
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, 363-883, Republic of Korea; Department of Bio-analytical Science, University of Science & Technology, Daejeon, 34113, Republic of Korea
| | - Song Yub Shin
- Department of Medical Science, Graduate School and Department of Cellular & Molecular Medicine, School of Medicine, Chosun University, Gwangju, 501-759, Republic of Korea.
| | - Jeong Kyu Bang
- Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chung-Buk, 363-883, Republic of Korea; Department of Bio-analytical Science, University of Science & Technology, Daejeon, 34113, Republic of Korea.
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105
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Malanovic N, Lohner K. Antimicrobial Peptides Targeting Gram-Positive Bacteria. Pharmaceuticals (Basel) 2016; 9:E59. [PMID: 27657092 PMCID: PMC5039512 DOI: 10.3390/ph9030059] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/07/2016] [Accepted: 09/13/2016] [Indexed: 01/01/2023] Open
Abstract
Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan. While interaction of AMPs with peptidoglycan might rather facilitate penetration, interaction with anionic teichoic acids may act as either a trap for AMPs or a ladder for a route to the cytoplasmic membrane. Interaction with the cytoplasmic membrane frequently leads to lipid segregation affecting membrane domain organization, which affects membrane permeability, inhibits cell division processes or leads to delocalization of essential peripheral membrane proteins. Further, precursors of cell wall components, especially the highly conserved lipid II, are directly targeted by AMPs. Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which in addition can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target.
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Affiliation(s)
- Nermina Malanovic
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
| | - Karl Lohner
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Austria.
- BioTechMed Graz, Humboldtstrasse 50/III, 8010 Graz, Austria.
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106
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Singh J, Joshi S, Mumtaz S, Maurya N, Ghosh I, Khanna S, Natarajan VT, Mukhopadhyay K. Enhanced Cationic Charge is a Key Factor in Promoting Staphylocidal Activity of α-Melanocyte Stimulating Hormone via Selective Lipid Affinity. Sci Rep 2016; 6:31492. [PMID: 27526963 PMCID: PMC4985751 DOI: 10.1038/srep31492] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 07/20/2016] [Indexed: 02/07/2023] Open
Abstract
The steady rise in antimicrobial resistance poses a severe threat to global public health by hindering treatment of an escalating spectrum of infections. We have previously established the potent activity of α-MSH, a 13 residue antimicrobial peptide, against the opportunistic pathogen Staphylococcus aureus. Here, we sought to determine whether an increase in cationic charge in α-MSH could contribute towards improving its staphylocidal potential by increasing its interaction with anionic bacterial membranes. For this we designed novel α-MSH analogues by replacing polar uncharged residues with lysine and alanine. Similar to α-MSH, the designed peptides preserved turn/random coil conformation in artificial bacterial mimic 1,2-dimyristoyl-sn-glycero-3-phosphocholine:1,2-dimyristoyl-sn-glycero-3-phospho-rac-(1-glycerol) (7:3, w/w) vesicles and showed preferential insertion in the hydrophobic core of anionic membranes. Increased cationic charge resulted in considerable augmentation of antibacterial potency against MSSA and MRSA. With ~18-fold better binding than α-MSH to bacterial mimic vesicles, the most charged peptide KKK-MSH showed enhanced membrane permeabilization and depolarization activity against intact S. aureus. Scanning electron microscopy confirmed a membrane disruptive mode of action for KKK-MSH. Overall, increasing the cationic charge improved the staphylocidal activity of α-MSH without compromising its cell selectivity. The present study would help in designing more effective α-MSH-based peptides to combat clinically relevant staphylococcal infections.
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Affiliation(s)
- Jyotsna Singh
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
| | - Seema Joshi
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
| | - Sana Mumtaz
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
| | - Nancy Maurya
- Biochemistry and Environmental Toxicology Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
| | - Ilora Ghosh
- Biochemistry and Environmental Toxicology Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
| | - Shivangi Khanna
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110020, India
| | - Vivek T Natarajan
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi-110020, India
| | - Kasturi Mukhopadhyay
- Antimicrobial Research Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi-110067, India
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107
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Balandin SV, Ovchinnikova TV. Antimicrobial peptides of invertebrates. Part 2. biological functions and mechanisms of action. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2016. [DOI: 10.1134/s106816201604004x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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108
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Abdel-Shafi S, Osman A, Enan G, El-Nemer M, Sitohy M. Antibacterial activity of methylated egg white proteins against pathogenic G(+) and G(-) bacteria matching antibiotics. SPRINGERPLUS 2016; 5:983. [PMID: 27429892 PMCID: PMC4932028 DOI: 10.1186/s40064-016-2625-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 06/19/2016] [Indexed: 01/21/2023]
Abstract
Native egg white protein with high level of acidic amino acid residues (pI = 4.8) and hydrophilic nature was transformed into its methylated derivative (MEW), acquiring rather hydrophobic and basic character (pI = 8). The MIC of MEW against ten studied bacteria (G+ and G−) ranged between 0.5 and 1 μg/disc matching or excelling the comparative values of some known specific antibiotics (ranging from 1 to 7.5 μg/disc). Combinations of MEW (1 MIC) and different ready-made disc concentrations of antibiotics indicated either nil, antagonistic or synergistic antimicrobial effect. Replacing the antibiotic Ciprofloxacin by gradual levels of MEW (20–100 %) proportionally increased the potentiality to induce bigger sized inhibition zones. MEW (1 MIC) could inhibit the growth of 6 G+ and 4 G− pathogenic bacteria in their liquid broth media during 24 h at 37 °C, indicating its broad and wide specificity. TEM examination indicated the susceptibility of the two types of bacteria (G+ and G−) to the antimicrobial action of MEW as manifested in different signs of cellular deformations, confirming its broad specificity and its mode of action was rather targeting the cell wall and cell membrane.
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Affiliation(s)
- Seham Abdel-Shafi
- Botany Department, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
| | - Ali Osman
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511 Egypt
| | - Gamal Enan
- Botany Department, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
| | - Mona El-Nemer
- Botany Department, Faculty of Science, Zagazig University, Zagazig, 44519 Egypt
| | - Mahmoud Sitohy
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511 Egypt
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109
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Song R, Yang P, Wei R, Ruan G. Antioxidative, Antibacterial, and Food Functional Properties of the Half-Fin Anchovy Hydrolysates-Glucose Conjugates Formed via Maillard Reaction. Molecules 2016; 21:E795. [PMID: 27331806 PMCID: PMC6273840 DOI: 10.3390/molecules21060795] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/13/2016] [Accepted: 06/13/2016] [Indexed: 11/30/2022] Open
Abstract
The antioxidative, antibacterial, and food functional properties of the half-fin anchovy hydrolysates (HAHp)-glucose conjugates formed by Maillard reaction (MR) were investigated, respectively. Results of sugar and amino acid contents loss rates, browning index, and molecular weight distribution indicated that the initial pH of HAHp played an important role in the process of MR between HAHp and glucose. HAHp-glucose Maillard reaction products (HAHp-G MRPs) demonstrated enhanced antioxidative activities of reducing power and scavenging DPPH radicals compared to control groups. HAHp-G MRPs produced from the condition of pH 9.6 displayed the strongest reducing power. The excellent scavenging activity on DPPH radicals was found for HAHp(5.6)-G MRPs which was produced at pH 5.6. Additionally, HAHp(5.6)-G MRPs showed variable antibacterial activities against Escherichia coli, Pseudomonas fluorescens, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Bacillus megaterium, and Sarcina lutea, with the MIC values ranging from 8.3 to 16.7 μg/mL. Result of scanning electron microscopy (SEM) on E. coli suggested that HAHp(5.6)-G MRPs exhibited antibacterial activity by destroying the cell integrity through membrane permeabilization. Moreover, HAHp(5.6)-G MRPs had excellent foaming ability and stability at alkaline conditions of pH 8.0, and showed emulsion properties at acidic pH 4.0. These results suggested that specific HAHp-G MRPs should be promising functional ingredients used in foods.
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Affiliation(s)
- Ru Song
- Zhejiang Provincial Key Laboratory of Health Risk Factors for Seafood, College of Food Science and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China.
| | - Peiyu Yang
- Zhejiang Provincial Key Laboratory of Health Risk Factors for Seafood, College of Food Science and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China.
| | - Rongbian Wei
- College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
| | - Guanqiang Ruan
- Zhejiang Provincial Key Laboratory of Health Risk Factors for Seafood, College of Food Science and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China.
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110
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Structural Studies of a Lipid-Binding Peptide from Tunicate Hemocytes with Anti-Biofilm Activity. Sci Rep 2016; 6:27128. [PMID: 27292548 PMCID: PMC4904370 DOI: 10.1038/srep27128] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 05/13/2016] [Indexed: 11/21/2022] Open
Abstract
Clavanins is a class of peptides (23aa) histidine-rich, free of post-translational modifications. Clavanins have been studied largely for their ability to disrupt bacterial membranes. In the present study, the interaction of clavanin A with membranes was assessed by dynamic light scattering, zeta potential and permeabilization assays. We observed through those assays that clavanin A lysis bacterial cells at concentrations corresponding to its MIC. Further, the structure and function of clavanin A was investigated. To better understand how clavanin interacted with bacteria, its NMR structure was elucidated. The solution state NMR structure of clavanin A in the presence of TFE-d3 indicated an α-helical conformation. Secondary structures, based on circular dichroism measurements in anionic sodium dodecyl sulfate (SDS) and TFE (2,2,2-trifluorethanol), in silico lipid-peptide docking and molecular simulations with lipids DPPC and DOPC revealed that clavanin A can adopt a variety of folds, possibly influencing its different functions. Microcalorimetry assays revealed that clavanin A was capable of discriminating between different lipids. Finally, clavanin A was found to eradicate bacterial biofilms representing a previously unrecognized function.
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111
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Abstract
Host-defense peptides (HDPs) are promising next generation of antibiotic agents, as they have the potential to circumvent emerging drug resistance, due to their mechanism of bacterial killing through disruption of their membranes. Nonetheless, HDPs have intrinsic drawbacks such as low-to-moderate activity, susceptibility to enzymatic degradation. In the past few years, we developed a new class of peptidomimetics named 'γ-AApeptides', which have superior resistance to proteolysis and a variety of diversification via straightforward synthesis. Our recent studies suggested that γ-AApeptides can mimic the bactericidal mechanism of HDPs and show potent and broad-spectrum activity against both Gram-positive and Gram-negative multidrug-resistant bacteria. In this review, we summarize our current studies of antimicrobial γ-AApeptides and discuss their potential future development as antimicrobial peptidomimetics.
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112
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Dong W, Dong Z, Mao X, Sun Y, Li F, Shang D. Structure-activity analysis and biological studies of chensinin-1b analogues. Acta Biomater 2016; 37:59-68. [PMID: 27060618 DOI: 10.1016/j.actbio.2016.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 03/28/2016] [Accepted: 04/05/2016] [Indexed: 11/17/2022]
Abstract
UNLABELLED Chensinin-1b shows a potent and broad-spectrum bactericidal activity and no hemolytic activity and thus is a potential therapeutic agent against bacterial infection. The NMR structure of chensinin-1b consists of a partially α-helical region (residues 8-14) in a membrane-mimic environment that is distinct from other common antimicrobial peptides. However, further analysis of the structural features of chensinin-1b is required to better understand its bactericidal activity. In this study, a series of N- and C-terminally truncated or amino acid-substituted chensinin-1b analogues were synthesized. Next, the bactericidal activity and bacterial membrane effects of the analogues were investigated. The results indicated that the N-terminal residues play a more significant role than the C-terminal residues in the antimicrobial activity of chensinin-1b. The removal of five amino acids from the C-terminus of chensinin-1b did not affect its biological properties, but helix disruption significantly decreased bactericidal activity. The substitution of positively charged residues increased the helicity and antimicrobial activity of the peptide. We also identified a novel analogue [R(4),R(10)]C1b(3-13) that exhibited similar bactericidal properties with its parent peptide chensinin-1b. Electrostatic interactions between the selected analogues and lipopolysaccharides or cells were detected using isothermal titration calorimetry or zeta potential. The thermodynamic parameters ΔH and ΔS for [R(4),R(10)]C1b(3-13) were -20.48kcalmol(-1) and -0.0408kcalmol(-1)deg(-1), respectively. Chensinin-1b yielded similar results of -26.36kcalmol(-1) and -0.0559kcalmol(-1)deg(-1) for ΔH and ΔS, respectively. These results are consistence with their antimicrobial activities. Lastly, membrane depolarization studies showed that selected analogues exerted bactericidal activity by damaging the cytoplasmic membrane. STATEMENT OF SIGNIFICANCE Antimicrobial peptide chensinin-1b is a candidate for the development of new drugs and a template for the design of synthetic analogues. It mainly exhibits a random coil conformation in membrane environment, and in this manuscript, we characterized the structure of chensinin-1b using NMR spectroscopy, its structure is different than the structures of magainin 2, which has an α-helical conformation and indolicidin, which has a random coil structure. The structural features of chensinin-1b that are required for its potent bactericidal activity were also elucidated. Based on these data, we can fully understand the structure-activity relationship of such peptide and identified a novel analogue with properties that make it an attractive topic for future therapeutic research.
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Affiliation(s)
- Weibing Dong
- School of Life Science, Liaoning Normal University, Dalian 116081, China; Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian 116081, China
| | - Zhe Dong
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, China; Instrumental Analysis Center, Inner Mongolia University for Nationalities, Tongliao 028043, China
| | - Xiaoman Mao
- School of Life Science, Liaoning Normal University, Dalian 116081, China
| | - Yue Sun
- School of Life Science, Liaoning Normal University, Dalian 116081, China
| | - Fei Li
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, China.
| | - Dejing Shang
- School of Life Science, Liaoning Normal University, Dalian 116081, China; Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian 116081, China.
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113
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Fox SJ, Fazil MHUT, Dhand C, Venkatesh M, Goh ETL, Harini S, Eugene C, Lim RR, Ramakrishna S, Chaurasia SS, Beuerman RW, Verma CS, Verma NK, Loh XJ, Lakshminarayanan R. Insight into membrane selectivity of linear and branched polyethylenimines and their potential as biocides for advanced wound dressings. Acta Biomater 2016; 37:155-64. [PMID: 27079762 DOI: 10.1016/j.actbio.2016.04.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 12/14/2022]
Abstract
UNLABELLED We report here structure-property relationship between linear and branched polyethylene imines by examining their antimicrobial activities against wide range of pathogens. Both the polymers target the cytoplasmic membrane of bacteria and yeasts, eliciting rapid microbicidal properties. Using multiscale molecular dynamic simulations, we showed that, in both fully or partially protonated forms LPEI discriminates between mammalian and bacterial model membranes whereas BPEI lacks selectivity for both the model membranes. Simulation results suggest that LPEI forms weak complex with the zwitterionic lipids whereas the side chain amino groups of BPEI sequester the zwitterionic lipids by forming tight complex. Consistent with these observations, label-free cell impedance measurements, cell viability assays and high content analysis indicate that BPEI is cytotoxic to human epithelial and fibroblasts cells. Crosslinking of BPEI onto electrospun gelatin mats attenuate the cytotoxicity for fibroblasts while retaining the antimicrobial activity against Gram-positive and yeasts strains. PEI crosslinked gelatin mats elicit bactericidal activity by contact-mediated killing and durable to leaching for 7days. The potent antimicrobial activity combined with enhanced selectivity of the crosslinked ES gelatin mats would expand the arsenel of biocides in the management of superficial skin infections. The contact-mediated microbicidal properties may avert antimicrobial resistance and expand the diversity of applications to prevent microbial contamination. STATEMENT OF SIGNIFICANCE Current commercially available advanced wound dressings are either impregnated with metallic silver or silver salts which have side effects or may not avert antimicrobial resistance. In this article, we have used multidisciplinary approach comprising of computational, chemical and biological methods to understand the antimicrobial properties and biocompatibility of linear (LPEI) and branched (BPEI) polyethylenimines. We then applied this knowledge to develop dual purpose wound dressings containing these polymers, which encourages healing while maintain antimicrobial activity. In addition, the approach can be expanded to rationalize the antimicrobial vs. cytotoxicity of other cationic polymers and the method of crosslinking would enhance their potentials as biocides for advanced materials.
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114
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Transcriptome analysis of Streptococcus pneumoniae treated with the designed antimicrobial peptides, DM3. Sci Rep 2016; 6:26828. [PMID: 27225022 PMCID: PMC4881017 DOI: 10.1038/srep26828] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/09/2016] [Indexed: 11/18/2022] Open
Abstract
In our previous studies, we generated a short 13 amino acid antimicrobial peptide (AMP), DM3, showing potent antipneumococcal activity in vitro and in vivo. Here we analyse the underlying mechanisms of action using Next-Generation transcriptome sequencing of penicillin (PEN)-resistant and PEN-susceptible pneumococci treated with DM3, PEN, and combination of DM3 and PEN (DM3PEN). DM3 induced differential expression in cell wall and cell membrane structural and transmembrane processes. Notably, DM3 altered the expression of competence-induction pathways by upregulating CelA, CelB, and CglA while downregulating Ccs16, ComF, and Ccs4 proteins. Capsular polysaccharide subunits were downregulated in DM3-treated cells, however, it was upregulated in PEN- and DM3PEN-treated groups. Additionally, DM3 altered the amino acids biosynthesis pathways, particularly targeting ribosomal rRNA subunits. Downregulation of cationic AMPs resistance pathway suggests that DM3 treatment could autoenhance pneumococci susceptibility to DM3. Gene enrichment analysis showed that unlike PEN and DM3PEN, DM3 treatment exerted no effect on DNA-binding RNA polymerase activity but observed downregulation of RpoD and RNA polymerase sigma factor. In contrast to DM3, DM3PEN altered the regulation of multiple purine/pyrimidine biosynthesis and metabolic pathways. Future studies based on in vitro experiments are proposed to investigate the key pathways leading to pneumococcal cell death caused by DM3.
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Siala W, Van Bambeke F, Taresco V, Piozzi A, Francolini I. Synergistic activity between an antimicrobial polyacrylamide and daptomycin versusStaphylococcus aureusbiofilm. Pathog Dis 2016; 74:ftw042. [DOI: 10.1093/femspd/ftw042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2016] [Indexed: 11/13/2022] Open
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Takahashi C, Akachi Y, Ogawa N, Moriguchi K, Asaka T, Tanemura M, Kawashima Y, Yamamoto H. Morphological study of efficacy of clarithromycin-loaded nanocarriers for treatment of biofilm infection disease. Med Mol Morphol 2016; 50:9-16. [PMID: 27119723 DOI: 10.1007/s00795-016-0141-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 04/11/2016] [Indexed: 11/24/2022]
Abstract
In this study, we developed a drug delivery system (DDS) using polymeric nanocarriers for the treatment of biofilm infection disease. Clarithromycin (CAM)-encapsulated and chitosan (CS) modified polymeric nanoparticles (NPs) were prepared using a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) (Sol) and poly-(DL-lactide-co-glycolide), respectively. To understand the availability of the prepared NPs, we made morphological observations of the antibacterial activity derived from the NPs toward the bacterial cells within the biofilm using scanning electron microscopy and transmission electron microscopy measurements. These results revealed different antibacterial activities for the two types of drug carriers. In the case of CAM-encapsulated + CS-modified Sol micelles treatment, NPs can exert their antibacterial activity not only by the surfactant, CAM and CS effects but also by intrusion into the bacterial cells. Thereby, CAM-encapsulated + CS-modified Sol micelles had a higher antibacterial activity. The morphological information is useful to design suitable NPs for the treatment against biofilm infections.
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Affiliation(s)
- Chisato Takahashi
- School of Pharmacy, Pharmaceutical Engineering, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan.
| | - Yuki Akachi
- School of Pharmacy, Pharmaceutical Engineering, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan
| | - Noriko Ogawa
- School of Pharmacy, Pharmaceutical Engineering, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan
| | - Keiichi Moriguchi
- Department of Oral Anatomy, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan
| | - Toru Asaka
- Department of Materials Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan
| | - Masaki Tanemura
- Department of Frontier Materials, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555, Japan
| | - Yoshiaki Kawashima
- School of Pharmacy, Pharmaceutical Engineering, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan
| | - Hiromitsu Yamamoto
- School of Pharmacy, Pharmaceutical Engineering, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi, 464-8650, Japan
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Yazici H, O'Neill MB, Kacar T, Wilson BR, Oren EE, Sarikaya M, Tamerler C. Engineered Chimeric Peptides as Antimicrobial Surface Coating Agents toward Infection-Free Implants. ACS APPLIED MATERIALS & INTERFACES 2016; 8:5070-81. [PMID: 26795060 PMCID: PMC5310947 DOI: 10.1021/acsami.5b03697] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property.
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Affiliation(s)
- Hilal Yazici
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
- Department of Molecular Biology and Genetics, Molecular Biology, Biotechnology and Genetic Center, Istanbul Technical University, Istanbul 34469, Turkey
| | - Mary B. O'Neill
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Turgay Kacar
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
- Department of Molecular Biology and Genetics, Molecular Biology, Biotechnology and Genetic Center, Istanbul Technical University, Istanbul 34469, Turkey
| | - Brandon R. Wilson
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - E. Emre Oren
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
- Department of Biomedical Engineering, TOBB University of Economics and Technology, Ankara 06560, Turkey
| | - Mehmet Sarikaya
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Candan Tamerler
- Genetically Engineered Materials Science and Engineering Center, Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
- Department of Mechanical Engineering, Bioengineering Research Center, University of Kansas, Lawrence, Kansas 66045, United States
- Corresponding Author Phone: 785-864-2984. . Corresponding author address: Bioengineering Research Center, Department of Mechanical Engineering, 1530 W, 15th St, Learned Hall, Lawrence, KS 66047
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Two-peptide bacteriocin PlnEF causes cell membrane damage to Lactobacillus plantarum. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:274-80. [DOI: 10.1016/j.bbamem.2015.11.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 09/16/2015] [Accepted: 11/21/2015] [Indexed: 11/24/2022]
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119
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Sitohy M, Mahgoub S, Osman A, El-Masry R, Al-Gaby A. Extent and Mode of Action of Cationic Legume Proteins against Listeria monocytogenes and Salmonella Enteritidis. Probiotics Antimicrob Proteins 2016; 5:195-205. [PMID: 26782988 DOI: 10.1007/s12602-013-9134-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The methylated soybean protein and methylated chickpea protein (MSP and MCP) with isoelectric points around pI 8 were prepared by esterifying 83 % of their free carboxyl groups and tested for their interactions with Listeria monocytogenes and Salmonella Enteritidis. The two substances exhibited a concentration-dependent inhibitory action against the two studied bacteria with a minimum inhibitory concentration of about 100 μg/mL. The IC50 % of the two proteins against L. monocytogenes (17 μg/mL) was comparable to penicillin but comparatively much lower (15 μg/mL) than that of penicillin (85 μg/mL) against S. Enteritidis. The two proteins could inhibit the growth of L. monocytogenes and S. Enteritidis by about 97 and 91 %, respectively, after 6-12 h of incubation at 37 °C. The constituting subunits of MSP (methylated 11S and methylated 7S) were both responsible for its antimicrobial action. Transmission electron microscopy of the protein-treated bacteria showed various signs of cellular deformation. The cationic proteins can electrostatically and hydrophobically interact with cell wall and cell membrane, producing large pores, pore channels and cell wall and cell membrane disintegration, engendering higher cell permeability leading finally to cell emptiness, lysis and death.
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Affiliation(s)
- Mahmoud Sitohy
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt.
| | - Samir Mahgoub
- Microbiology Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt
| | - Ali Osman
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt
| | - Ragab El-Masry
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt
| | - Aly Al-Gaby
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt
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Brannan AM, Whelan WA, Cole E, Booth V. Differential scanning calorimetry of whole Escherichia coli treated with the antimicrobial peptide MSI-78 indicate a multi-hit mechanism with ribosomes as a novel target. PeerJ 2015; 3:e1516. [PMID: 26713257 PMCID: PMC4690349 DOI: 10.7717/peerj.1516] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/27/2015] [Indexed: 11/20/2022] Open
Abstract
Differential Scanning Calorimetry (DSC) of intact Escherichia coli (E. coli) was used to identify non-lipidic targets of the antimicrobial peptide (AMP) MSI-78. The DSC thermograms revealed that, in addition to its known lytic properties, MSI-78 also has a striking effect on ribosomes. MSI-78’s effect on DSC scans of bacteria was similar to that of kanamycin, an antibiotic drug known to target the 30S small ribosomal subunit. An in vitro transcription/translation assay helped confirm MSI-78’s targeting of ribosomes. The scrambled version of MSI-78 also affected the ribosome peak of the DSC scans, but required greater amounts of peptide to cause a similar effect to the unscrambled peptide. Furthermore, the effect of the scrambled peptide was not specific to the ribosomes; other regions of the DSC thermogram were also affected. These results suggest that MSI-78’s effects on E. coli are at least somewhat dependent on its particular structural features, rather than a sole function of its overall charge and hydrophobicity. When considered along with earlier work detailing MSI-78’s membrane lytic properties, it appears that MSI-78 operates via a multi-hit mechanism with multiple targets.
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Affiliation(s)
- Alexander M Brannan
- Department of Biochemistry, Memorial University of Newfoundland , St. John's Newfoundland and Labrador , Canada
| | - William A Whelan
- Department of Biochemistry, Memorial University of Newfoundland , St. John's Newfoundland and Labrador , Canada
| | - Emma Cole
- Department of Biochemistry, Memorial University of Newfoundland , St. John's Newfoundland and Labrador , Canada
| | - Valerie Booth
- Department of Biochemistry, Memorial University of Newfoundland , St. John's Newfoundland and Labrador , Canada ; Department of Physics and Physical Oceanography, Memorial University of Newfoundland , St. John's Newfoundland and Labrador , Canada
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Design, synthesis and mode of action of novel 2-(4-aminophenyl)benzothiazole derivatives bearing semicarbazone and thiosemicarbazone moiety as potent antimicrobial agents. Med Chem Res 2015. [DOI: 10.1007/s00044-015-1479-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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122
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Preparation and characterization of antimicrobial cationized peptides from barley (Hordeum vulgare L.) proteins. Lebensm Wiss Technol 2015. [DOI: 10.1016/j.lwt.2015.03.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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123
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Laverty G, McCloskey AP, Gorman SP, Gilmore BF. Anti-biofilm activity of ultrashort cinnamic acid peptide derivatives against medical device-related pathogens. J Pept Sci 2015; 21:770-8. [PMID: 26310860 DOI: 10.1002/psc.2805] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 06/26/2015] [Accepted: 07/06/2015] [Indexed: 11/11/2022]
Abstract
The threat of antimicrobial resistance has placed increasing emphasis on the development of innovative approaches to eradicate multidrug-resistant pathogens. Biofilm-forming microorganisms, for example, Staphylococcus epidermidis and Staphylococcus aureus, are responsible for increased incidence of biomaterial infection, extended hospital stays and patient morbidity and mortality. This paper highlights the potential of ultrashort tetra-peptide conjugated to hydrophobic cinnamic acid derivatives. These peptidomimetic molecules demonstrate selective and highly potent activity against resistant biofilm forms of Gram-positive medical device-related pathogens. 3-(4-Hydroxyphenyl)propionic)-Orn-Orn-Trp-Trp-NH2 displays particular promise with minimum biofilm eradication concentration (MBEC) values of 125 µg/ml against methicillin sensitive (ATCC 29213) and resistant (ATCC 43300) S. aureus and activity shown against biofilm forms of Escherichia coli (MBEC: 1000 µg/ml). Kill kinetics confirms complete eradication of established 24-h biofilms at MBEC with 6-h exposure. Reduced cell cytotoxicity, relative to Gram-positive pathogens, was proven via tissue culture (HaCaT) and haemolysis assays (equine erythrocytes). Existing in nature as part of the immune response, antimicrobial peptides display great promise for exploitation by the pharmaceutical industry in order to increase the library of available therapeutic molecules. Ultrashort variants are particularly promising for translation as clinical therapeutics as they are more cost-effective, easier to synthesise and can be tailored to specific functional requirements based on the primary sequence allowing factors such as spectrum of activity to be varied.
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Affiliation(s)
- Garry Laverty
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Alice P McCloskey
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Sean P Gorman
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
| | - Brendan F Gilmore
- Biomaterials, Biofilm and Infection Control Research Group, School of Pharmacy, Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK
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Xi D, Wang X, Teng D, Mao R. Mechanism of action of the tri-hybrid antimicrobial peptide LHP7 from lactoferricin, HP and plectasin on Staphylococcus aureus. Biometals 2015; 27:957-68. [PMID: 25015218 DOI: 10.1007/s10534-014-9768-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 06/24/2014] [Indexed: 11/28/2022]
Abstract
The tri-hybrid peptide-LHP7 has the potent activity against Gram-positive and Gram-negative as well as fungi, but its mechanism of action has remained elusive. The effluences of LHP7 on the Staphylococcus aureus cell membrane and targets of intracellular action were investigated. LHP7 exhibited an inhibitory effect on the S. aureus growth, similar to those achieved by plectasin, vancomycin and gramicidin. The membrane integrity studies confirmed that LHP7 disrupted the cell membrane, indicating a membrane permeabilizing killing action. A marginal decline in the intensity fluorescence indicated no significant depolarization of the membrane potential following LHP7 treatment. Furthermore, electron microscopy showed that cell shrinkage, cell wall thickening, cellular content leakage, and cell disruption were observed in the cells treated with LHP7. A gel retardation assay showed that LHP7 bound to the genomic DNA of S. aureus or plasmid DNA at a mass ratio of 2.5–10 (peptide/DNA). Circular dichroism indicated that LHP7 inserted into the groove of DNA. The cell cycle analysis showed that after the treatment with LHP7 for 30 and 60 min, the proportion of cells in I-phase increased from 8.71 to 12.09 % and from 8.71 to 15.68 %, indicating that LHP7 induced arrest of cells in the I-phase. These results would conduce to elucidate its underlying antibacterial mechanism.
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125
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Wang Z, de la Fuente-Núñez C, Shen Y, Haapasalo M, Hancock REW. Treatment of Oral Multispecies Biofilms by an Anti-Biofilm Peptide. PLoS One 2015; 10:e0132512. [PMID: 26168273 PMCID: PMC4500547 DOI: 10.1371/journal.pone.0132512] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/15/2015] [Indexed: 11/18/2022] Open
Abstract
Human oral biofilms are multispecies microbial communities that exhibit high resistance to antimicrobial agents. Dental plaque gives rise to highly prevalent and costly biofilm-related oral infections, which lead to caries or other types of oral infections. We investigated the ability of the recently identified anti-biofilm peptide 1018 to induce killing of bacterial cells present within oral multispecies biofilms. At 10 μg/ml (6.5 μM), peptide 1018 was able to significantly (p<0.05) prevent biofilm formation over 3 days. The activity of the peptide on preformed biofilms was found to be concentration-dependent since more than 60% of the total plaque biofilm cell population was killed by 10 μg/ml of peptide 1018 in 3 days, while at 5 μg/ml 50% of cells were dead and at 1 μg/ml the peptide triggered cell death in around 30% of the total bacterial population, as revealed by confocal microscopy. The presence of saliva did not affect peptide activity, since no statistically significant difference was found in the ability of peptide 1018 to kill oral biofilms using either saliva coated and non-saliva coated hydroxyapatite surfaces. Scanning electron microscopy experiments indicated that peptide 1018 induced cell lysis in plaque biofilms. Furthermore, combined treatment using peptide 1018 and chlorhexidine (CHX) increased the anti-biofilm activity of each compound compared to when these were used alone, resulting in >50% of the biofilm being killed and >35% being dispersed in only 3 minutes. Peptide 1018 may potentially be used by itself or in combination with CHX as a non-toxic and effective anti-biofilm agent for plaque disinfection in clinical dentistry.
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Affiliation(s)
- Zhejun Wang
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan, PR China
| | - Cesar de la Fuente-Núñez
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Ya Shen
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Markus Haapasalo
- Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail: (MH); (REWH)
| | - Robert E. W. Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
- * E-mail: (MH); (REWH)
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Rajamuthiah R, Jayamani E, Conery AL, Fuchs BB, Kim W, Johnston T, Vilcinskas A, Ausubel FM, Mylonakis E. A Defensin from the Model Beetle Tribolium castaneum Acts Synergistically with Telavancin and Daptomycin against Multidrug Resistant Staphylococcus aureus. PLoS One 2015; 10:e0128576. [PMID: 26062137 PMCID: PMC4465704 DOI: 10.1371/journal.pone.0128576] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/28/2015] [Indexed: 01/19/2023] Open
Abstract
The red flour beetle Tribolium castaneum is a common insect pest and has been established as a model beetle to study insect development and immunity. This study demonstrates that defensin 1 from T. castaneum displays in vitro and in vivo antimicrobial activity against drug resistant Staphylococcus aureus strains. The minimum inhibitory concentration (MIC) of defensin 1 against 11 reference and clinical staphylococcal isolates was between 16–64 μg/ml. The putative mode of action of the defensin peptide is disruption of the bacterial cell membrane. The antibacterial activity of defensin 1 was attenuated by salt concentrations of 1.56 mM and 25 mM for NaCl and CaCl2 respectively. Treatment of defensin 1 with the reducing agent dithiothreitol (DTT) at concentrations 1.56 to 3.13 mM abolished the antimicrobial activity of the peptide. In the presence of subinhibitory concentrations of antibiotics that also target the bacterial cell envelope such as telavancin and daptomycin, the MIC of the peptide was as low as 1 μg/ml. Moreover, when tested against an S. aureus strain that was defective in D-alanylation of the cell wall, the MIC of the peptide was 0.5 μg/ml. Defensin 1 exhibited no toxicity against human erythrocytes even at 400 μg/ml. The in vivo activity of the peptide was validated in a Caenorhabditis elegans-MRSA liquid infection assay. These results suggest that defensin 1 behaves similarly to other cationic AMPs in its mode of action against S. aureus and that the activity of the peptide can be enhanced in combination with other antibiotics with similar modes of action or with compounds that have the ability to decrease D-alanylation of the bacterial cell wall.
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Affiliation(s)
- Rajmohan Rajamuthiah
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
| | - Elamparithi Jayamani
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
| | - Annie L. Conery
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
| | - Beth Burgwyn Fuchs
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
| | - Wooseong Kim
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
| | - Tatiana Johnston
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
| | - Andreas Vilcinskas
- Institute of Phytopathology and Applied Zoology, Justus-Liebig University, Heinrich-Buff-Ring 26–32, 35392, Giessen, Germany
| | - Frederick M. Ausubel
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
| | - Eleftherios Mylonakis
- Division of Infectious Diseases, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, 02903, United States of America
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
- * E-mail:
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de Melo ET, Estrela AB, Santos ECG, Machado PRL, Farias KJS, Torres TM, Carvalho E, Lima JPMS, Silva-Júnior AA, Barbosa EG, Fernandes-Pedrosa MDF. Structural characterization of a novel peptide with antimicrobial activity from the venom gland of the scorpion Tityus stigmurus: Stigmurin. Peptides 2015; 68:3-10. [PMID: 25805002 DOI: 10.1016/j.peptides.2015.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/02/2015] [Accepted: 03/05/2015] [Indexed: 01/05/2023]
Abstract
A new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5μM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug.
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Affiliation(s)
- Edinara Targino de Melo
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Andréia Bergamo Estrela
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | | | | | | | - Taffarel Melo Torres
- Departamento de Ciências Animais, Universidade Federal Rural do Semi-Árido, Mossoró, RN, Brazil
| | - Enéas Carvalho
- Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil
| | | | - Arnóbio Antonio Silva-Júnior
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | | | - Matheus de Freitas Fernandes-Pedrosa
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Programa de Pós-Graduação em Bioquímica, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
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Rabanal F, Grau-Campistany A, Vila-Farrés X, Gonzalez-Linares J, Borràs M, Vila J, Manresa A, Cajal Y. A bioinspired peptide scaffold with high antibiotic activity and low in vivo toxicity. Sci Rep 2015; 5:10558. [PMID: 26024044 PMCID: PMC4603705 DOI: 10.1038/srep10558] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/20/2015] [Indexed: 02/07/2023] Open
Abstract
Bacterial resistance to almost all available antibiotics is an important public health issue. A major goal in antimicrobial drug discovery is the generation of new chemicals capable of killing pathogens with high selectivity, particularly multi-drug-resistant ones. Here we report the design, preparation and activity of new compounds based on a tunable, chemically accessible and upscalable lipopeptide scaffold amenable to suitable hit-to-lead development. Such compounds could become therapeutic candidates and future antibiotics available on the market. The compounds are cyclic, contain two D-amino acids for in vivo stability and their structures are reminiscent of other cyclic disulfide-containing peptides available on the market. The optimized compounds prove to be highly active against clinically relevant Gram-negative and Gram-positive bacteria. In vitro and in vivo tests show the low toxicity of the compounds. Their antimicrobial activity against resistant and multidrug-resistant bacteria is at the membrane level, although other targets may also be involved depending on the bacterial strain.
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Affiliation(s)
- Francesc Rabanal
- Department of Organic Chemistry, Faculty of Chemistry, University of Barcelona
| | | | - Xavier Vila-Farrés
- Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - University of Barcelona
| | | | - Miquel Borràs
- Experimental Toxicology and Ecotoxicology Unit /CERETOX, Barcelona Science Park
| | - Jordi Vila
- Barcelona Centre for International Health Research (CRESIB), Hospital Clínic - University of Barcelona
| | - Angeles Manresa
- Laboratory of Microbiology, Faculty of Pharmacy, University of Barcelona
| | - Yolanda Cajal
- Department of Physical Chemistry, Faculty of Pharmacy, University of Barcelona
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129
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Application of immobilized synthetic anti-lipopolysaccharide peptides for the isolation and detection of bacteria. Eur J Clin Microbiol Infect Dis 2015; 34:1639-45. [DOI: 10.1007/s10096-015-2399-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/03/2015] [Indexed: 11/25/2022]
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In vitro properties of designed antimicrobial peptides that exhibit potent antipneumococcal activity and produces synergism in combination with penicillin. Sci Rep 2015; 5:9761. [PMID: 25985150 PMCID: PMC4434909 DOI: 10.1038/srep09761] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/18/2015] [Indexed: 11/22/2022] Open
Abstract
Antimicrobial peptides (AMPs) represent a promising class of novel antimicrobial agents owing to their potent antimicrobial activity. In this study, two lead peptides from unrelated classes of AMPs were systematically hybridized into a series of five hybrid peptides (DM1- DM5) with conserved N- and C-termini. This approach allows sequence bridging of two highly dissimilar AMPs and enables sequence-activity relationship be detailed down to single amino acid level. Presence of specific amino acids and physicochemical properties were used to describe the antipneumococcal activity of these hybrids. Results obtained suggested that cell wall and/or membrane targeting could be the principal mechanism exerted by the hybrids leading to microbial cell killing. Moreover, the pneumocidal rate was greater than penicillin (PEN). Combination treatment with both DMs and PEN produced synergism. The hybrids were also broad spectrum against multiple common clinical bacteria. Sequence analysis showed that presence of specific residues has a major role in affecting the antimicrobial and cell toxicity of the hybrids than physicochemical properties. Future studies should continue to investigate the mechanisms of actions, in vivo therapeutic potential, and improve rational peptide design based on the current strategy.
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131
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Equilibrium binding behavior of magnesium to wall teichoic acid. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1981-7. [PMID: 25969394 DOI: 10.1016/j.bbamem.2015.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 04/20/2015] [Accepted: 05/06/2015] [Indexed: 11/21/2022]
Abstract
Peptidoglycan and teichoic acids are the major cell wall components of Gram-positive bacteria that obtain and sequester metal ions required for biochemical processes. The delivery of metals to the cytoplasmic membrane is aided by anionic binding sites within the peptidoglycan and along the phosphodiester polymer of teichoic acid. The interaction with metals is a delicate balance between the need for attraction and ion diffusion to the membrane. Likewise, metal chelation from the extracellular fluid must initially have strong binding energetics that weaken within the cell wall to enable ion release. We employed atomic absorption and equilibrium dialysis to measure the metal binding capacity and metal binding affinity of wall teichoic acid and Mg2+. Data show that Mg2+ binds to WTA with a 1:2Mg2+ to phosphate ratio with a binding capacity of 1.27 μmol/mg. The affinity of Mg2+ to WTA was also found to be 41×10(3) M(-1) at low metal concentrations and 1.3×10(3) M(-1) at higher Mg2+ concentrations due to weakening electrostatic effects. These values are lower than the values describing Mg2+ interactions with peptidoglycan. However, the binding capacity of WTA is 4 times larger than peptidoglycan. External WTA initially binds metals with positive cooperativity, but metal binding switches to negative cooperativity, whereas interior WTA binds metals with only negative cooperativity. The relevance of this work is to describe changes in metal binding behavior depending on environment. When metals are sparse, chelation is strong to ensure survival yet the binding weakens when essential minerals are abundant.
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Improved antibacterial phototoxicity of a neutral porphyrin in natural deep eutectic solvents. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 148:188-196. [PMID: 25966307 DOI: 10.1016/j.jphotobiol.2015.04.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/09/2015] [Accepted: 04/20/2015] [Indexed: 11/20/2022]
Abstract
Neutral porphyrins for antibacterial photodynamic therapy (aPDT) have received little attention due to their tendency to aggregate in aqueous media and reports of low phototoxic effect. These compounds may be less toxic to cells than positively and negatively charged photosensitisers. The preparation of highly bacterial phototoxic formulations of neutral porphyrins remains an open field of research with great potential if achievable. The purpose of this study was to develop novel hydrophilic formulations of the neutral porphyrin 5,10,15,20-tetrakis(4-hydroxyphenyl)-porphyrin (THPP) by use of natural deep eutectic solvents (NADES) prepared by the solvent evaporation method. Physical and photochemical stability and in vitro photoinactivation of Enterococcus faecalis and Escherichia coli were investigated. Two of the 15 NADES investigated demonstrated superior solubilising properties of THPP. The photostability of THPP was higher in NADES than in methanol. A 100-fold dilution of the preparations with buffer to a final concentration of 0.5-5 nM THPP resulted in complete photoinactivation of E. faecalis and E. coli both in their exponential and stationary phase. THPP demonstrated significantly higher phototoxicity when formulated in NADES than in other aqueous preparations like phosphate buffered saline. NADES as a formulation concept for photosensitisers shows a great potential in aPDT.
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da Silva Domingues JF, Roest S, Wang Y, van der Mei HC, Libera M, van Kooten TG, Busscher HJ. Macrophage phagocytic activity toward adhering staphylococci on cationic and patterned hydrogel coatings versus common biomaterials. Acta Biomater 2015; 18:1-8. [PMID: 25752975 DOI: 10.1016/j.actbio.2015.02.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/30/2015] [Accepted: 02/27/2015] [Indexed: 02/06/2023]
Abstract
Biomaterial-associated-infection causes failure of biomaterial implants. Many new biomaterials have been evaluated for their ability to inhibit bacterial colonization and stimulate tissue-cell-integration, but neglect the role of immune cells. This paper compares macrophage phagocytosis of adhering Staphylococcus aureus on cationic-coatings and patterned poly(ethylene)glycol-hydrogels versus common biomaterials and stainless steel in order to identify surface conditions that promote clearance of adhering bacteria. Staphylococci were allowed to adhere and grow on the materials in a parallel-plate-flow-chamber, after which murine macrophages were introduced. From the decrease in the number of adhering staphylococci, phagocytosis-rates were calculated, and total macrophage displacements during an experiment determined. Hydrophilic surfaces had the lowest phagocytosis-rates, while common biomaterials had intermediate phagocytosis-rates. Patterning of poly(ethylene)glycol-hydrogel coatings increased phagocytosis-rates to the level of common biomaterials, while on cationic-coatings phagocytosis-rates remained relatively low. Likely, phagocytosis-rates on cationic coatings are hampered relative to common biomaterials through strong electrostatic binding of negatively-charged macrophages and staphylococci. On polymeric biomaterials and glass, phagocytosis-rates increased with macrophage displacement, while both parameters increased with biomaterial surface hydrophobicity. Thus hydrophobicity is a necessary surface condition for effective phagocytosis. Concluding, next-generation biomaterials should account for surface effects on phagocytosis in order to enhance the ability of these materials to resist biomaterial-associated-infection.
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Bera S, Ghosh A, Sharma S, Debnath T, Giri B, Bhunia A. Probing the role of Proline in the antimicrobial activity and lipopolysaccharide binding of indolicidin. J Colloid Interface Sci 2015; 452:148-159. [PMID: 25935286 DOI: 10.1016/j.jcis.2015.04.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/12/2015] [Accepted: 04/13/2015] [Indexed: 01/28/2023]
Abstract
HYPOTHESIS Indolicidin (ILPWKWPWWPWRR-NH2), an antimicrobial peptide from bovine neutrophils, possesses significant antibacterial activity. An interesting feature of indolicidin is its unusually high content of Tryptophan and Proline residues. While the involvement of Tryptophan has been studied for its hemolytic and antibacterial activity, little is known about the roles played by Proline in these aspects. We herein investigate the structure and biological activities of indolicidin, where Proline at either one or more of the 3rd, 7th, 10th positions has been replaced by Alanine to better understand its structure and biological function. EXPERIMENTS Structural aspects of Proline residues of indolicidin and its effect on antimicrobial activity were elucidated by replacing Proline residues with Alanine. Minimum inhibitory concentration (MIC) and scanning electron microscopy (SEM) experiments provide substantial evidence for the importance of Proline residues for antimicrobial activity and cell wall disintegration. Binding affinity of the peptides to Lipopolysaccharide (LPS) was investigated using fluorescence spectroscopy and dynamic light scattering (DLS) in conjunction with (31)PNMR spectroscopy and confirmed the disintegration of LPS layer. FINDINGS Our study reveals that Proline residues are necessary for interaction of indolicidin with LPS and establishes the significance of the third and tenth Proline residues for its antimicrobial activity. We believe that the presence of so many Proline residues provides the molecule a selective advantage of adopting different conformations varying from a globular, closed conformation to an open extended conformation, and even to a wedge-shaped conformation, which account for the diverse mechanisms of action of indolicidin.
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Affiliation(s)
- Swapna Bera
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Anirban Ghosh
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Shruti Sharma
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Tanmoy Debnath
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Banabihari Giri
- Central Instrument Facility, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), Kolkata 700054, India.
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135
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Carvacrol codrugs: a new approach in the antimicrobial plan. PLoS One 2015; 10:e0120937. [PMID: 25859852 PMCID: PMC4393269 DOI: 10.1371/journal.pone.0120937] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 02/09/2015] [Indexed: 01/10/2023] Open
Abstract
Objective The increasing prevalence of antibiotic-resistant bacterial infections led to identify alternative strategies for a novel therapeutic approach. In this study, we synthesized ten carvacrol codrugs – obtained linking the carvacrol hydroxyl group to the carboxyl moiety of sulphur-containing amino acids via an ester bond – to develop novel compounds with improved antimicrobial and antibiofilm activities and reduced toxicity respect to carvacrol alone. Method All carvacrol codrugs were screened against a representative panel of Gram positive (S. aureus and S. epidermidis), Gram negative (E. coli and P. aeruginosa) bacterial strains and C. albicans, using broth microdilution assays. Findings Results showed that carvacrol codrug 4 possesses the most notable enhancement in the anti-bacterial activity displaying MIC and MBC values equal to 2.5 mg/mL for all bacterial strains, except for P. aeruginosa ATCC 9027 (MIC and MBC values equal to 5 mg/mL and 10 mg/mL, respectively). All carvacrol codrugs 1-10 revealed good antifungal activity against C. albicans ATCC 10231. The cytotoxicity assay showed that the novel carvacrol codrugs did not produce human blood hemolysis at their MIC values except for codrugs 8 and 9. In particular, deepened experiments performed on carvacrol codrug 4 showed an interesting antimicrobial effect on the mature biofilm produced by E. coli ATCC 8739, respect to the carvacrol alone. The antimicrobial effects of carvacrol codrug 4 were also analyzed by TEM evidencing morphological modifications in S. aureus, E. coli, and C. albicans. Conclusion The current study presents an insight into the use of codrug strategy for developing carvacrol derivatives with antibacterial and antibiofilm potentials, and reduced cytotoxicity.
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Usachev KS, Efimov SV, Kolosova OA, Filippov AV, Klochkov VV. High-resolution NMR structure of the antimicrobial peptide protegrin-2 in the presence of DPC micelles. JOURNAL OF BIOMOLECULAR NMR 2015; 61:227-34. [PMID: 25430060 DOI: 10.1007/s10858-014-9885-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/20/2014] [Indexed: 05/22/2023]
Abstract
PG-1 adopts a dimeric structure in dodecylphosphocholine (DPC) micelles, and a channel is formed by the association of several dimers but the molecular mechanisms of the membrane damage by non-α-helical peptides are still unknown. The formation of the PG-1 dimer is important for pore formation in the lipid bilayer, since the dimer can be regarded as the primary unit for assembly into the ordered aggregates. It was supposed that only 12 residues (RGGRL-CYCRR-RFCVC-V) are needed to endow protegrin molecules with strong antibacterial activity and that at least four additional residues are needed to add potent antifungal properties. Thus, the 16-residue protegrin (PG-2) represents the minimal structure needed for broad-spectrum antimicrobial activity encompassing bacteria and fungi. As the peptide conformation and peptide-to-membrane binding properties are very sensitive to single amino acid substitutions, the solution structure of PG-2 in solution and in a membrane mimicking environment are crucial. In order to find evidence if the oligomerization state of PG-1 in a lipid environment will be the same or not for another protegrins, we investigate in the present work the PG-2 NMR solution structure in the presence of perdeuterated DPC micelles. The NMR study reported in the present work indicates that PG-2 form a well-defined structure (PDB: 2MUH) composed of a two-stranded antiparallel β-sheet when it binds to DPC micelles.
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Affiliation(s)
- K S Usachev
- Kazan Federal University, Kremlevskaya, 18, Kazan, 420008, Russian Federation,
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137
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Anil Kumar S, Hima Kumari P, Shravan Kumar G, Mohanalatha C, Kavi Kishor PB. Osmotin: a plant sentinel and a possible agonist of mammalian adiponectin. FRONTIERS IN PLANT SCIENCE 2015; 6:163. [PMID: 25852715 PMCID: PMC4360817 DOI: 10.3389/fpls.2015.00163] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 03/01/2015] [Indexed: 05/18/2023]
Abstract
Osmotin is a stress responsive antifungal protein belonging to the pathogenesis-related (PR)-5 family that confers tolerance to both biotic and abiotic stresses in plants. Protective efforts of osmotin in plants range from high temperature to cold and salt to drought. It lyses the plasma membrane of the pathogens. It is widely distributed in fruits and vegetables. It is a differentially expressed and developmentally regulated protein that protects the cells from osmotic stress and invading pathogens as well, by structural or metabolic alterations. During stress conditions, osmotin helps in the accumulation of the osmolyte proline, which quenches reactive oxygen species and free radicals. Osmotin expression results in the accumulation of storage reserves and increases the shelf-life of fruits. It binds to a seven-transmembrane-domain receptor-like protein and induces programmed cell death in Saccharomyces cerevisiae through RAS2/cAMP signaling pathway. Adiponectin, produced in adipose tissues of mammals, is an insulin-sensitizing hormone. Strangely, osmotin acts like the mammalian hormone adiponectin in various in vitro and in vivo models. Adiponectin and osmotin, the two receptor binding proteins do not share sequence similarity at the amino acid level, but interestingly they have a similar structural and functional properties. In experimental mice, adiponectin inhibits endothelial cell proliferation and migration, primary tumor growth, and reduces atherosclerosis. This retrospective work examines the vital role of osmotin in plant defense and as a potential targeted therapeutic drug for humans.
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Affiliation(s)
- S. Anil Kumar
- Department of Genetics, Osmania University, HyderabadIndia
| | - P. Hima Kumari
- Department of Genetics, Osmania University, HyderabadIndia
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138
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Kim JS, Jeong JH, Kim KS, Kim Y. Optimized Expression and Characterization of Antimicrobial Peptides, LPcin Analogs. B KOREAN CHEM SOC 2015. [DOI: 10.1002/bkcs.10213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ji-Sun Kim
- Department of Chemistry and Protein Research Center for Bio-Industry; Hankuk University of Foreign Studies; Yong-In 449-791 Republic of Korea
| | - Ji-Ho Jeong
- Department of Chemistry and Protein Research Center for Bio-Industry; Hankuk University of Foreign Studies; Yong-In 449-791 Republic of Korea
| | - Kyung-Sup Kim
- Department of Chemistry and Protein Research Center for Bio-Industry; Hankuk University of Foreign Studies; Yong-In 449-791 Republic of Korea
| | - Yongae Kim
- Department of Chemistry and Protein Research Center for Bio-Industry; Hankuk University of Foreign Studies; Yong-In 449-791 Republic of Korea
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139
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Enzymatic hydrolyzed feather peptide, a welcoming drug for multiple-antibiotic-resistant Staphylococcus aureus: structural analysis and characterization. Appl Biochem Biotechnol 2015; 175:3371-86. [PMID: 25649444 DOI: 10.1007/s12010-015-1509-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 01/21/2015] [Indexed: 10/24/2022]
Abstract
This study aimed to explore the bactericidal activity of a feather-degraded active peptide against multiple-antibiotic-resistant (MAR) Staphylococcus aureus. An antibacterial peptide (ABP) was isolated from the chicken feathers containing fermented media of Paenibacillus woosongensis TKB2, a keratinolytic soil isolate. It was purified by HPLC, and its mass was found to be 4666.87 Da using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) spectroscopy. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of this peptide were 22.5 and 90 μg/ml, respectively. SEM study revealed the distorted cell wall of the test strain along with pore formation. The possible reason for bactericidal activity of the peptide is due to generation of reactive oxygen species (ROS), resulting in membrane damage and leakage of intracellular protein. Complete sequence of the peptide was predicted and retrieved from the sequence database of chicken feather keratin after in silico trypsin digestion using ExPASy tools. Further, net charge, hydrophobicity (77.7 %) and molecular modelling of the peptide were evaluated for better understanding of its mode of action. The hydrophobic region (17 to 27) of the peptide may facilitate for initial attachment on the bacterial membrane. The ABP exhibited no adverse effects on RBC membrane and HT-29 human cell line. This cytosafe peptide can be exploited as an effective therapeutic agent to combat Staphylococcal infections.
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140
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Targeted separation of antibacterial peptide from protein hydrolysate of anchovy cooking wastewater by equilibrium dialysis. Food Chem 2015; 168:115-23. [DOI: 10.1016/j.foodchem.2014.07.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 06/07/2014] [Accepted: 07/06/2014] [Indexed: 12/25/2022]
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141
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Characterization of a novel small molecule that potentiates β-lactam activity against gram-positive and gram-negative pathogens. Antimicrob Agents Chemother 2015; 59:1876-85. [PMID: 25583731 DOI: 10.1128/aac.04164-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In a loss-of-viability screen using small molecules against methicillin-resistant Staphylococcus aureus (MRSA) strain USA300 with a sub-MIC of a β-lactam, we found a small molecule, designated DNAC-1, which potentiated the effect of oxacillin (i.e., the MIC of oxacillin decreased from 64 to 0.25 μg/ml). Fluorescence microscopy indicated a disruption in the membrane structures within 15 min of exposure to DNAC-1 at 2× MIC. This permeabilization was accompanied by a rapid loss of membrane potential, as monitored by use of the DiOC2 (3,3'-diethyloxacarbocyanine iodide) dye. Macromolecular analysis showed the inhibition of staphylococcal cell wall synthesis by DNAC-1. Transmission electron microscopy of treated MRSA USA300 cells revealed a slightly thicker cell wall, together with mesosome-like projections into the cytosol. The exposure of USA300 cells to DNAC-1 was associated with the mislocalization of FtsZ accompanied by the localization of penicillin-binding protein 2 (PBP2) and PBP4 away from the septum, as well as mild activation of the vraRS-mediated cell wall stress response. However, DNAC-1 does not have any generalized toxicity toward mammalian host cells. DNAC-1 in combination with ceftriaxone is also effective against an assortment of Gram-negative pathogens. Using a murine subcutaneous coinjection model with 10(8) CFU of USA300 as a challenge inoculum, DNAC-1 alone or DNAC-1 with a sub-MIC of oxacillin resulted in a 6-log reduction in bacterial load and decreased abscess formation compared to the untreated control. We propose that DNAC-1, by exerting a bimodal effect on the cell membrane and cell wall, is a viable candidate in the development of combination therapy against many common bacterial pathogens.
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142
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Mohamed MF, Hammac GK, Guptill L, Seleem MN. Antibacterial activity of novel cationic peptides against clinical isolates of multi-drug resistant Staphylococcus pseudintermedius from infected dogs. PLoS One 2014; 9:e116259. [PMID: 25551573 PMCID: PMC4281220 DOI: 10.1371/journal.pone.0116259] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 12/04/2014] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus pseudintermedius is a major cause of skin and soft tissue infections in companion animals and has zoonotic potential. Additionally, methicillin-resistant S. pseudintermedius (MRSP) has emerged with resistance to virtually all classes of antimicrobials. Thus, novel treatment options with new modes of action are required. Here, we investigated the antimicrobial activity of six synthetic short peptides against clinical isolates of methicillin-susceptible and MRSP isolated from infected dogs. All six peptides demonstrated potent anti-staphylococcal activity regardless of existing resistance phenotype. The most effective peptides were RRIKA (with modified C terminus to increase amphipathicity and hydrophobicity) and WR-12 (α-helical peptide consisting exclusively of arginine and tryptophan) with minimum inhibitory concentration50 (MIC50) of 1 µM and MIC90 of 2 µM. RR (short anti-inflammatory peptide) and IK8 “D isoform” demonstrated good antimicrobial activity with MIC50 of 4 µM and MIC90 of 8 µM. Penetratin and (KFF)3K (two cell penetrating peptides) were the least effective with MIC50 of 8 µM and MIC90 of 16 µM. Killing kinetics revealed a major advantage of peptides over conventional antibiotics, demonstrating potent bactericidal activity within minutes. Studies with propidium iodide and transmission electron microscopy revealed that peptides damaged the bacterial membrane leading to leakage of cytoplasmic contents and consequently, cell death. A potent synergistic increase in the antibacterial effect of the cell penetrating peptide (KFF)3K was noticed when combined with other peptides and with antibiotics. In addition, all peptides displayed synergistic interactions when combined together. Furthermore, peptides demonstrated good therapeutic indices with minimal toxicity toward mammalian cells. Resistance to peptides did not evolve after 10 passages of S. pseudintermedius at sub-inhibitory concentration. However, the MICs of amikacin and ciprofloxacin increased 32 and 8 fold, respectively; under similar conditions. Taken together, these results support designing of peptide-based therapeutics for combating MRSP infections, particularly for topical application.
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Affiliation(s)
- Mohamed F Mohamed
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
| | - G Kenitra Hammac
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
| | - Lynn Guptill
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
| | - Mohamed N Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, United States of America
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143
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New role for human α-defensin 5 in the fight against hypervirulent Clostridium difficile strains. Infect Immun 2014; 83:986-95. [PMID: 25547793 DOI: 10.1128/iai.02955-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile infection (CDI), one of the most common hospital-acquired infections, is increasing in incidence and severity with the emergence and diffusion of hypervirulent strains. CDI is precipitated by antibiotic treatment that destroys the equilibrium of the gut microbiota. Human α-defensin 5 (HD5), the most abundant enteric antimicrobial peptide, is a key regulator of gut microbiota homeostasis, yet it is still unknown if C. difficile, which successfully evades killing by other host microbicidal peptides, is susceptible to HD5. We evaluated, by means of viability assay, fluorescence-activated cell sorter (FACS) analysis, and electron microscopy, the antimicrobial activities of α-defensins 1 and 5 against a panel of C. difficile strains encompassing the most prevalent epidemic and hypervirulent PCR ribotypes in Europe (012, 014/020, 106, 018, 027, and 078). Here we show that (i) concentrations of HD5 within the intestinal physiological range produced massive C. difficile cell killing; (ii) HD5 bactericidal activity was mediated by membrane depolarization and bacterial fragmentation with a pattern of damage peculiar to C. difficile bacilli, compared to commensals like Escherichia coli and Enterococcus faecalis; and (iii) unexpectedly, hypervirulent ribotypes were among the most susceptible to both defensins. These results support the notion that HD5, naturally present at very high concentrations in the mucosa of the small intestine, could indeed control the very early steps of CDI by killing C. difficile bacilli at their germination site. As a consequence, HD5 can be regarded as a good candidate for the containment of hypervirulent C. difficile strains, and it could be exploited in the therapy of CDI and relapsing C. difficile-associated disease.
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DuBuc TQ, Dattoli AA, Babonis LS, Salinas-Saavedra M, Röttinger E, Martindale MQ, Postma M. In vivo imaging of Nematostella vectensis embryogenesis and late development using fluorescent probes. BMC Cell Biol 2014; 15:44. [PMID: 25433655 PMCID: PMC4264334 DOI: 10.1186/s12860-014-0044-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 11/19/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cnidarians are the closest living relatives to bilaterians and have been instrumental to studying the evolution of bilaterian properties. The cnidarian model, Nematostella vectensis, is a unique system in which embryology and regeneration are both studied, making it an ideal candidate to develop in vivo imaging techniques. Live imaging is the most direct way for quantitative and qualitative assessment of biological phenomena. Actin and tubulin are cytoskeletal proteins universally important for regulating many embryological processes but so far studies in Nematostella primarily focused on the localization of these proteins in fixed embryos. RESULTS We used fluorescent probes expressed in vivo to investigate the dynamics of Nematostella development. Lifeact-mTurquoise2, a fluorescent cyan F-actin probe, can be visualized within microvilli along the cellular surface throughout embryonic development and is stable for two months after injection. Co-expression of Lifeact-mTurquoise2 with End-Binding protein1 (EB1) fused to mVenus or tdTomato-NLS allows for the visualization of cell-cycle properties in real time. Utilizing fluorescent probes in vivo helped to identify a concentrated 'flash' of Lifeact-mTurquoise2 around the nucleus, immediately prior to cytokinesis in developing embryos. Moreover, Lifeact-mTurquoise2 expression in adult animals allowed the identification of various cell types as well as cellular boundaries. CONCLUSION The methods developed in this manuscript provide an alternative protocol to investigate Nematostella development through in vivo cellular analysis. This study is the first to utilize the highly photo-stable florescent protein mTurquoise2 as a marker for live imaging. Finally, we present a clear methodology for the visualization of minute temporal events during cnidarian development.
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145
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Pereira MA, Faustino MAF, Tomé JPC, Neves MGPMS, Tomé AC, Cavaleiro JAS, Cunha Â, Almeida A. Influence of external bacterial structures on the efficiency of photodynamic inactivation by a cationic porphyrin. Photochem Photobiol Sci 2014; 13:680-90. [PMID: 24549049 DOI: 10.1039/c3pp50408e] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The main targets of photodynamic inactivation (PDI) are the external bacterial structures, cytoplasmic membrane and cell wall. In this work it was evaluated how the external bacterial structures influence the PDI efficiency. To reach this objective 8 bacteria with distinct external structures were selected; 4 Gram-negative bacteria (Escherichia coli, with typical Gram-negative external structures; Aeromonas salmonicida, Aeromonas hydrophila both with an S-layer and Rhodopirellula sp., with a peptidoglycan-less proteinaceous cell wall and with cytoplasm compartmentalization) and 4 Gram-positive bacteria (Staphylococcus aureus, with typical Gram-positive external structures; Truepera radiovictrix, Deinococcus geothermalis and Deinococcus radiodurans, all with thick cell walls that give them Gram-positive stains, but including a second complex multi-layered membrane and structurally analogous to that of Gram-negative bacteria). The studies were performed in the presence of 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetraiodide (Tetra-Py(+)-Me) at 5.0 μM with white light (40 W m(-2)). The susceptibility of each bacteria to PDI by Tetra-Py(+)-Me was dependent on bacteria external structures. Although all Gram-positive bacteria were inactivated to the detection limit (reduction of ∼8 log) after 60-180 min of irradiation, the inactivation followed distinct patterns. Among the Gram-negative bacteria, E. coli was the only species to be inactivated to the detection limit (∼8 log after 180 min). The efficiency of inactivation of the two species of Aeromonas was similar (reduction of ∼5-6 log after 270 min). Rhodopirellula was less susceptible (reduction of ∼4 log after 270 min). As previously observed, the Gram-positive bacteria are more easily inactivated than Gram-negative strains, and this is even true for T. radiovictrix, D. geothermalis and D. radiodurans, which have a complex multi-layered cell wall. The results support the theory that the outer cell structures are major bacterial targets for PDI. Moreover, the chemical composition of the external structures has a stronger effect on PDI efficiency than complexity and the number of layers of the external coating, and lipids seem to be an important target of PDI.
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Affiliation(s)
- M A Pereira
- Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal.
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146
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Shin SY. Effect of Double Replacement of L-Pro, D-Pro, D-Leu or Nleu in Hydrophobic Face of Amphipathic α-Helical Model Antimicrobial Peptide on Structure, Cell Selectivity and Mechanism of Action. B KOREAN CHEM SOC 2014. [DOI: 10.5012/bkcs.2014.35.11.3267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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147
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Cheng M, Huang JX, Ramu S, Butler MS, Cooper MA. Ramoplanin at bactericidal concentrations induces bacterial membrane depolarization in Staphylococcus aureus. Antimicrob Agents Chemother 2014; 58:6819-27. [PMID: 25182650 PMCID: PMC4249368 DOI: 10.1128/aac.00061-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 08/26/2014] [Indexed: 12/22/2022] Open
Abstract
Ramoplanin is an actinomycetes-derived antibiotic with broad-spectrum activity against Gram-positive bacteria that has been evaluated in clinical trials for the treatment of gastrointestinal vancomycin-resistant enterococci (VRE) and Clostridium difficile infections. Recent studies have proposed that ramoplanin binds to bacterial membranes as a C2 symmetrical dimer that can sequester Lipid II, which causes inhibition of cell wall peptidoglycan biosynthesis and cell death. In this study, ramoplanin was shown to bind to anionic and zwitterionic membrane mimetics with a higher affinity for anionic membranes and to induce membrane depolarization of methicillin-susceptible Staphylococcus aureus (MSSA) ATCC 25923 at concentrations at or above the minimal bactericidal concentration (MBC). The ultrastructural effects of ramoplanin on S. aureus were also examined by transmission electron microscopy (TEM), and this showed dramatic changes to bacterial cell morphology. The correlation observed between membrane depolarization and bacterial cell viability suggests that this mechanism may contribute to the bactericidal activity of ramoplanin.
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Affiliation(s)
- Mu Cheng
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Johnny X Huang
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Soumya Ramu
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark S Butler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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148
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Teng P, Wu H, Lin L, Cai J. Antimicrobial γ-AApeptides (WO2013112548): a patent evaluation. Expert Opin Ther Pat 2014; 25:111-8. [PMID: 25331592 DOI: 10.1517/13543776.2014.973855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The patent application WO2013112548 claims a new class of peptidomimetics - γ-AApeptides with potent and broad-spectrum antimicrobial activity. These γ-AApeptides are active against both Gram-positive and Gram-negative bacteria, including medicinally relevant drug-resistant pathogens. They are believed to exert bactericidal function by mimicking the membrane disruption mechanism of host-defense peptides. As such, they may provide an alternative approach for antimicrobial development combating antibiotic resistance.
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Affiliation(s)
- Peng Teng
- University of South Florida, Department of Chemistry , 4202 E. Fowler Ave, Tampa, FL 33620 , USA +1 813 974 9506 ; +1 813 974 3203 ;
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Lü X, Hu P, Dang Y, Liu B. Purification and partial characterization of a novel bacteriocin produced by Lactobacillus casei TN-2 isolated from fermented camel milk (Shubat) of Xinjiang Uygur Autonomous region, China. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.03.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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150
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Méndez-Samperio P. Peptidomimetics as a new generation of antimicrobial agents: current progress. Infect Drug Resist 2014; 7:229-37. [PMID: 25210467 PMCID: PMC4155802 DOI: 10.2147/idr.s49229] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Antibiotic resistance is an increasing public health concern around the world. Rapid increase in the emergence of multidrug-resistant bacteria has been the target of extensive research efforts to develop a novel class of antibiotics. Antimicrobial peptides (AMPs) are small cationic amphiphilic peptides, which play an important role in the defense against bacterial infections through disruption of their membranes. They have been regarded as a potential source of future antibiotics, owing to a remarkable set of advantageous properties such as broad-spectrum activity, and they do not readily induce drug-resistance. However, AMPs have some intrinsic drawbacks, such as susceptibility to enzymatic degradation, toxicity, and high production cost. Currently, a new class of AMPs termed “peptidomimetics” have been developed, which can mimic the bactericidal mechanism of AMPs, while being stable to enzymatic degradation and displaying potent activity against multidrug-resistant bacteria. This review will focus on current findings of antimicrobial peptidomimetics. The potential future directions in the development of more potent analogs of peptidomimetics as a new generation of antimicrobial agents are also presented.
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Affiliation(s)
- Patricia Méndez-Samperio
- Department of Immunology, National School of Biological Sciences, National Polytechnic Institute, Mexico City, Mexico
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