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Antimicrobial peptides

Radhe Shyam, Nicolas Charbonnel, Aurélie Job, Christelle Blavignac, Christiane Forestier, Claude Taillefumier, Sophie Faure
Amphipathic cationic peptoids (N-substituted glycine oligomers) represent a promising class of antimicrobial peptide mimics. The aim of this study is to explore the potential of the triazolium group as a cationic moiety and helix inducer to develop potent antimicrobial helical peptoids. We report here the first solid-phase synthesis of peptoid oligomers incorporating 1,2,3-triazolium-type side chains, and their evaluation against Escherichia coli, Enterococcus faecalis and Staphylococcus aureus. Several triazolium-based oligomers, even of short length, selectively kill bacteria over mammalian cells...
June 19, 2018: ChemMedChem
Awatef Ouertani, Ines Chaabouni, Amor Mosbah, Justine Long, Mohamed Barakat, Pascal Mansuelle, Olfa Mghirbi, Afef Najjari, Hadda-Imene Ouzari, Ahmed S Masmoudi, Marc Maresca, Philippe Ortet, Didier Gigmes, Kamel Mabrouk, Ameur Cherif
Milk and dairy products harbor a wide variety of bacterial species that compete for both limited resources and space. Under these competitive conditions, bacteria develop specialized mechanisms to protect themselves during niche colonization and nutrient acquisition processes. The bacterial antagonism mechanisms include the production of antimicrobial agents or molecules that facilitate competitor dispersal. In the present work, a bacterial strain designated RC6 was isolated from Ricotta and identified as Bacillus cereus ...
2018: Frontiers in Microbiology
Zhongqi He, Dunhua Zhang, Heping Cao
Currently, there is only limited knowledge on the protein types and structures of the cottonseed proteins. In this work, water-soluble cottonseed proteins (CSPw) and alkali-soluble cottonseed proteins (CSPa) were sequentially extracted from defatted cottonseed meal. Proteins of the two fractions were separated by 4-20% gradient polyacrylamide gel electrophoresis (SDS-PAGE); There were 7 and 12 polypeptide bands on SDS-PAGE of CSPa and CSPw, respectively. These individual bands were then excised from the gel and subjected to mass spectrometric analysis...
June 18, 2018: Scientific Reports
Pauline Dartevelle, Claire Ehlinger, Abdurraouf Zaet, Christian Boehler, Morgane Rabineau, Benoit Westermann, Jean-Marc Strub, Sarah Cianferani, Youssef Haïkel, Marie-Hélène Metz-Boutigue, Céline Marban
The excessive use of antifungal agents, compounded by the shortage of new drugs being introduced into the market, is causing the accumulation of multi-resistance phenotypes in many fungal strains. Consequently, new alternative molecules to conventional antifungal agents are urgently needed to prevent the emergence of fungal resistance. In this context, Cateslytin (Ctl), a natural peptide derived from the processing of Chromogranin A, has already been described as an effective antimicrobial agent against several pathogens including Candida albicans...
June 18, 2018: Scientific Reports
Geneviève LeBel, Katy Vaillancourt, Li Yi, Marcelo Gottschalk, Daniel Grenier
Streptococcus suis is a major swine pathogen causing pathologies such as meningitis, sepsis, endocarditis, and arthritis. Several surface-bound and secreted proteases produced by S. suis have been identified and proposed as virulence factors. PR-39 is a proline/arginine-rich antimicrobial peptide produced by porcine leucocytes. In addition to play a role in innate immunity, this peptide possesses immunomodulatory properties. In this study, we hypothesized that proteases produced by S. suis inactivate PR-39...
June 15, 2018: Microbial Pathogenesis
Ammar Almaaytah, Mohammed T Qaoud, Ahmad Abualhaijaa, Qosay Al-Balas, Karem H Alzoubi
Introduction: As the development of new antimicrobial agents faces a historical decline, the issue of bacterial drug resistance has become a serious dilemma that threatens the human population worldwide. Antimicrobial peptides (AMPs) represent an attractive and a promising class of antimicrobial agents. Aim: The hybridization of AMPs aimed at merging two individual active fragments of native peptides to generate a new AMP with altered physicochemical properties that translate into an enhanced safety profile...
2018: Infection and Drug Resistance
Prapansak Srisapoome, Nawanith Klongklaew, Nontawith Areechon, Ratree Wongpanya
Anti-lipopolysaccharide factor (ALF) is an immune-related protein that is crucially involved in immune defense mechanisms against invading pathogens in crustaceans. In the current study, three different ALFs of giant river prawn (Mr-ALF3, Mr-ALF8 and Mr-ALF9) were discovered. Based on sequence analysis, Mr-ALF3 and Mr-ALF9 were identified as new members of ALFs in crustaceans (groups F and G, respectively). Structurally, each newly identified Mr-ALF contained three α-helices packed against a four-stranded β-sheet bearing the LPS-binding motif, which usually binds to the cell wall components of bacteria...
June 14, 2018: Fish & Shellfish Immunology
Yan Liu, Ying-Hao Zhang, Tong Li, Xiao-Tong Cao, Yang Zhou, Jun-Fa Yuan, Ze-Mao Gu, Jiang-Feng Lan
Antimicrobial peptides (AMPs) play important roles in innate immunity against pathogens and lysozymes are a particularly type of AMP. Lysozymes are hydrolytic enzymes that are characterized by their ability to cleave the beta-(1,4)-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycan, which is the major bacterial cell wall polymer. In this work, a lysozyme was identified from Procambarus clarkii and designated PcLys-i3. Quantitative RT-PCR was used to analyze the tissue distribution and expression profiles of PcLys-i3...
May 31, 2018: Developmental and Comparative Immunology
Soosan Abdollahi, Mohammad Hossein Ghahremani, Neda Setayesh, Nasrin Samadi
The Lactococcus lactis is known as a probiotic bacterium and also as a producer of nisin. Nisin has been approved by related legal agencies to be used as an antimicrobial peptide in food preservation. In fact, the L. lactis is present in different food products along with other micro-organisms especially pathogenic bacteria. So, it is important to predict the behavior of nisin-producer strain in contact with other pathogens. In this regard, nisin gene expression and the level of secreted biologically active form of nisin by L...
June 13, 2018: Microbial Pathogenesis
Sylvia Singh, Alekhya Nimmagadda, Ma Su, Minghui Wang, Peng Teng, Jianfeng Cai
With an increase of resistance in bacteria there is an urgent need for alternative treatment methods that could complement conventional antibiotics. In the past two decades, focus has been drawn to Host Defense Peptides (HDPs) as potential antibiotic agents. Herein we reported our studies on the development of lipidated α/α-AA heterogeneous peptides as a new class of HDP mimetics. These compounds showed potent antimicrobial activity toward both Gram-positive and Gram-negative bacteria, and they also displayed excellent selectivity as they only exhibited limited hemolytic activity...
June 5, 2018: European Journal of Medicinal Chemistry
Reza Akbari, Mojdeh Hakemi Vala, Ali Hashemi, Hossein Aghazadeh, Jean-Marc Sabatier, Kamran Pooshang Bagheri
The emergence and dissemination of multidrug resistant (MDR) bacteria are major challenges for antimicrobial chemotherapy of bacterial infections. In this critical condition, cationic antimicrobial peptides are 'novel' promising candidate antibiotics to overcome the issue. In this study, we investigated the antibacterial mechanism of new melittin-derived peptides (i.e., MDP1 and MDP2) against multidrug resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. MDP1 was designed with deletion of three amino acid residues, i...
June 15, 2018: Amino Acids
Xiaoling Chen, Luyao Zhang, Yue Wu, Lei Wang, Chengbang Ma, Xinping Xi, Olaf R P Bininda-Emonds, Chris Shaw, Tianbao Chen, Mei Zhou
Mastoparan is a typical cationic and amphipathic tetradecapeptide found in wasp venom and exhibits potent biological activities. Yet, compared with other insect-derived peptides, such as melittin from the bee venom, this family have been underrated. Herein, we evaluated the biological activities of mastoparan-C (MP-C), which was identified from the venom of the European Hornet ( Vespa crabro ), and rationally designed two analogues (a skeleton-based cyclization by two cysteine residues and an N-terminal extension via tat-linked) for enhancing the stability of the biological activity and membrane permeability, respectively...
2018: International Journal of Biological Sciences
Ping Zhao, Fei Xia, Liang Jiang, Huizhen Guo, Guowen Xu, Qiang Sun, Bingbing Wang, Yumei Wang, Zhongyan Lu, Qingyou Xia
In insect innate immunity, peptidoglycan recognition proteins act as pattern recognition receptors, helping hosts combat invasive microorganisms. Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is the main silkworm pathogen that invades the midgut columnar cell layer. We previously reported that B. mori peptidoglycan recognition protein S2 (BmPGRP-S2) was upregulated in silkworm larvae after BmCPV infection. Here, we constructed a transgenic vector overexpressing BmPGRP-S2 under the control of a midgut-specific promoter...
May 30, 2018: Developmental and Comparative Immunology
Dinglong Yang, Qianqian Zhang, Qing Wang, Lizhu Chen, Yongliang Liu, Ming Cong, Huifeng Wu, Fei Li, Chenglong Ji, Jianmin Zhao
Defensins are small cysteine-rich cationic proteins that are ubiquitously present in both vertebrates and invertebrates and constitute the front line of host innate immunity. In the present study, a defensin-like antimicrobial peptide (designed as RpdefB) was identified and characterized from the manila clam Ruditapes philippinarum. The open reading frame of RpdefB encoded a 70-amino acid polypeptide with a calculated molecular mass of 7.5 kDa and isoelectric point of 8.16. Multiple alignments and phylogenetic analysis strongly suggested that RpdefB was a new member of the defensin family...
June 11, 2018: Fish & Shellfish Immunology
Soraya Omardien, Jan W Drijfhout, Frédéric M Vaz, Michaela Wenzel, Leendert W Hamoen, Sebastian A J Zaat, Stanley Brul
BACKGROUND: Amphipathic cationic antimicrobial peptides (AMPs) TC19 and TC84, derived from the major AMPs of human blood platelets, thrombocidins, and Bactericidal Peptide 2 (BP2), a synthetic designer peptide showed to perturb the membrane of Bacillus subtilis. We aimed to determine the means by which the three AMPs cause membrane perturbation in vivo using B. subtilis and to evaluate whether the membrane alterations are dependent on the phospholipid composition of the membrane. METHODS: Physiological analysis was employed using Alexa Fluor 488 labelled TC84, various fluorescence dyes, fluorescent microscopy techniques and structured illumination microscopy...
June 11, 2018: Biochimica et Biophysica Acta
Markus Santhosh Braun, Frank Sporer, Stefan Zimmermann, Michael Wink
The function of uropygial glands (preen glands) has been subject to controversial debates. In this study, we evaluated the antimicrobial potential of preen gland secretions of turkeys (Meleagris gallopavo) against 18 microbial strains by means of diffusion tests, broth microdilutions, checkerboard assays, and time-kill curves. Furthermore, we tested the hypothesis that lipids exert direct antimicrobial effects on pathogens. Moreover, we checked for mutualistic relationships between the preen gland bacterium Corynebacterium uropygiale with its hosts...
June 12, 2018: FEMS Microbiology Ecology
Alan J Cameron, Kyriakos G Varnava, Patrick J B Edwards, Elena Harjes, Vijayalekshmi Sarojini
Three linear peptides incorporating d-Phe-2-Abz as the turn motif are reported. Peptide 1, a hydrophobic β-hairpin, served as a proof of principle for the design strategy with both NMR and CD spectra strongly suggesting a β-hairpin conformation. Peptides 2 and 3, designed as amphipathic antimicrobials, exhibited broad spectrum antimicrobial activity, with potency in the nanomolar range against Staphylococcus aureus. Both compounds possess a high degree of selectivity, proving non-haemolytic at concentrations 500 to 800 times higher than their respective minimal inhibitory concentrations (MICs) against S...
June 14, 2018: Journal of Peptide Science: An Official Publication of the European Peptide Society
Teruhisa Higuchi, Mitsuhiko Moriyama, Akiko Fukushima, Hiroshi Matsumura, Shunichi Matsuoka, Tatsuo Kanda, Masahiko Sugitani, Akiko Tsunemi, Takahiro Ueno, Noboru Fukuda
Background: Excess iron is associated with non-alcoholic steatohepatitis (NASH). Results: mRNA expression of duodenal cytochrome b, divalent metal transporter 1, ferroportin 1, hepcidin, hephaestin and transferrin receptor 1 in liver were higher in high fat, high cholesterol-containing diet (HFCD) group than in normal diet (ND) group. mRNA levels of divalent metal transporter 1 and transferrin receptor 1, which stimulate iron absorption and excretion, were enhanced in small intestine...
May 25, 2018: Oncotarget
Lihong Guo, Anna Edlund
No abstract text is available yet for this article.
October 2017: Journal of the California Dental Association
François Bédard, Riadh Hammami, Séverine Zirah, Sylvie Rebuffat, Ismail Fliss, Eric Biron
The antimicrobial peptide pediocin PA-1 is a class IIa bacteriocin that inhibits several clinically relevant pathogens including Listeria spp. Here we report the synthesis and characterization of whole pediocin PA-1 and novel analogs thereof using a combination of solid- and solution-phase strategies to overcome difficulties due to instability and undesired reactions. Pediocin PA-1 thus synthesized was a potent inhibitor of Listeria monocytogenes (MIC = 6.8 nM), similar to the bacteriocin produced naturally by Pediococcus acidilactici...
June 13, 2018: Scientific Reports
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