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cationic antimicrobial peptide

Dawei Xu, Qian Ran, Yang Xiang, Jiang Linhai, Britannia M Smith, Fadi Bou-Abdallah, Reidar Lund, Zhongjun Li, He Dong
A significant challenge associated with systemic delivery of cationic antimicrobial peptides and polymers lies in their limited hemocompatibility toward vast numbers of circulating red blood cells (RBCs). Supramolecular assembly of cationic peptides and polymers can be an effective strategy to develop an array of antimicrobial nanomaterials with tunable material structures, stability and thus optimized bioactivity to overcome some of the existing challenges associated with conventional antimicrobials. In this work, we will demonstrate the supramolecular design of self-assembling antimicrobial nanofibers (SAANs) which have tunable supramolecular nanostructures, stability, internal molecular packing and surface chemistry through self-assembly of de novo designed cationic peptides and peptide-PEG conjuguates...
2016: RSC Advances
Jie Chen, Qiang Chen, Xin-Jiang Lu, Jiong Chen
Liver-expressed antimicrobial peptide 2 (LEAP-2) is a cationic peptide that plays an important role in the host's innate immune system. However, the mechanism by which LEAP-2 modulates/regulates the host defense against pathogens remains largely unknown. In this study, we identified a cDNA sequence encoding LEAP-2 homolog (BpLEAP-2) in the mudskipper, Boleophthalmus pectinirostris. Sequence analysis revealed that BpLEAP-2 belonged to the fish LEAP-2A cluster and that it was closely related to ayu LEAP-2. BpLEAP-2 mRNA was detected in a wide range of tissues, with the highest level of transcripts found in the liver...
October 17, 2016: Fish & Shellfish Immunology
Oleg M Michurin, Sergii Afonin, Marina Berditsch, Constantin G Daniliuc, Anne S Ulrich, Igor V Komarov, Dmytro S Radchenko
Conformationally constrained non-racemizing trifluoromethyl-substituted lysine isosteres [(E)- and (Z)-TCBLys] with charged side chains are presented as a new type of (19) F-NMR labels for peptide studies. Design of the labels, their synthesis, incorporation into peptides and experimental demonstration of their application for solid state NMR studies of membrane-active peptides are described. A series of fluorine-labeled analogues of the helical amphipathic antimicrobial peptide PGLa(Nle) was obtained, in which different lysine residues in the original peptide sequence were replaced, one at a time, by either (E)- or (Z)-TCBLys...
October 20, 2016: Angewandte Chemie
Francis D O Ablan, B Logan Spaller, Kaitlyn I Abdo, Paulo F Almeida
Hundreds of cationic antimicrobial and cell-penetrating peptides (CPPs) form amphipathic α-helices when bound to lipid membranes. Here, we test two hypotheses for the differences in the ability of these peptides to translocate across membranes. The first, which we now call the hydrophobicity hypothesis, is that peptide translocation is determined by the Gibbs energy of insertion into the bilayer from the membrane interface. The second, which we call the charge-distribution hypothesis, is that translocation is determined by whether the distribution of cationic residues in the peptide can transiently stabilize a high-energy inserted intermediate by forming salt bridges to the phosphates of lipid headgroups...
October 18, 2016: Biophysical Journal
Tereza Tůmová, Lenka Monincová, Václav Čeřovský, Václav Kašička
Capillary electrophoresis (CE) was employed for the determination of thermodynamic acidity constants (pKa ) and actual ionic mobilities of polycationic antimicrobial peptides (AMPs). The effective electrophoretic mobilities of AMPs were measured by CE in a series of the background electrolytes within a wide pH range (2.00-12.25), at constant ionic strength (25 mM) and ambient temperature, using polybrene coated fused silica capillaries to suppress sorption of cationic AMPs to the capillary wall. Eventually, Haarhoff-Van der Linde peak fitting function was used for the determination of correct migration times of some AMPs peaks that were distorted by electromigration dispersion...
October 19, 2016: Electrophoresis
Zohaib Khurshid, Mustafa Naseem, Zeeshan Sheikh, Shariq Najeeb, Sana Shahab, Muhammad Sohail Zafar
Antimicrobial peptides (AMPs) are a wide-ranging class of host-defense molecules that act early to contest against microbial invasion and challenge. These are small cationic peptides that play an important in the development of innate immunity. In the oral cavity, the AMPs are produced by the salivary glands and the oral epithelium and serve defensive purposes. The aim of this review was to discuss the types and functions of oral AMPs and their role in combating microorganisms and infections in the oral cavity...
September 2016: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
Mi Ok Lee, Hyun-Jun Jang, Deivendran Rengaraj, Seo-Yeong Yang, Jae Yong Han, Susan J Lamont, James E Womack
BACKGROUND: Host defence peptides are a diverse group of small, cationic peptides and are important elements of the first line of defense against pathogens in animals. Expression and functional analysis of host defense peptides has been evaluated in chicken but there are no direct, comprehensive comparisons with all gene family and individual genes. RESULTS: We examined the expression patterns of all known cathelicidins, β-defensins and NK-lysin in multiple selected tissues from chickens...
October 13, 2016: BMC Veterinary Research
Srinivas Suda, Des Field, Niall Barron
Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis...
2017: Methods in Molecular Biology
G C A da Hora, N L Archilha, J L S Lopes, D M Müller, K Coutinho, R Itri, T A Soares
Antimicrobial peptides (AMPs) are cationic peptides that kill bacteria with a broad spectrum of action, low toxicity to mammalian cells and exceptionally low rates of bacterial resistance. These features have led to considerable efforts in developing AMPs as an alternative antibacterial therapy. In vitro studies have shown that AMPs interfere with membrane bilayer integrity via several possible mechanisms, which are not entirely understood. We have performed the synthesis, membrane lysis measurements, and biophysical characterization of a novel hybrid peptide...
September 26, 2016: Soft Matter
Lei Zhang, Dian Guo, Yangxin Liu, Yilan Shao, Yufeng Wang, Yigang Xu, Yanping Jiang, Wen Cui, Yijing Li, Lijie Tang
PR39, a 4.7 kDa proline-rich antimicrobial peptide, acts as a cationic host defense peptide. In addition to killing bacteria, PR39 mediates inflammatory reactions, including cell proliferation, migration, wound healing, and angiogenesis. Here, we examined the antibacterial effects of this peptide. The synthetic gene fragment PR39 was inserted into the secretory expression vector plasmid pPG:612 of Lactobacillus casei, yielding the recombinant strain pPG:612-PR39/L. casei 393. In vitro antibacterial tests showed that expression of the PR39 peptide in recombinant L...
July 7, 2016: Canadian Journal of Microbiology
Julien Verdon, Pierre Coutos-Thevenot, Marie-Helene Rodier, Celine Landon, Segolene Depayras, Cyril Noel, Sylvain La Camera, Bouziane Moumen, Pierre Greve, Didier Bouchon, Jean-Marc Berjeaud, Christine Braquart-Varnier
Antimicrobial peptides (AMPs) are key components of innate immunity and are widespread in nature, from bacteria to vertebrate animals. In crustaceans, there are currently 15 distinct AMP families published so far in the literature, mainly isolated from members of the Decapoda order. Up to now, armadillidin is the sole non-decapod AMP isolated from the haemocytes of Armadillidium vulgare, a crustacean isopod. Its first description demonstrated that armadillidin is a linear glycine-rich (47%) cationic peptide with an antimicrobial activity directed toward Bacillus megaterium...
2016: Frontiers in Microbiology
Patricia Losada-Pérez, Mehran Khorshid, Frank Uwe Renner
Despite the environmentally friendly reputation of ionic liquids (ILs), their safety has been recently questioned given their potential as cytotoxic agents. The fundamental mechanisms underlying the interactions between ILs and cells are less studied and by far not completely understood. Biomimetic films are here important biophysical model systems to elucidate fundamental aspects and mechanisms relevant for a large range of biological interaction ranging from signaling to drug reception or toxicity. Here we use dissipative quartz crystal microbalance QCM-D to examine the effect of aqueous imidazolium-based ionic liquid mixtures on solid-supported biomimetic membranes...
2016: PloS One
Samuel I Miller
The Gram-negative outer membrane is an important barrier that provides protection against toxic compounds, which include antibiotics and host innate immune molecules such as cationic antimicrobial peptides. Recently, significant research progress has been made in understanding the biogenesis, regulation, and functioning of the outer membrane, including a recent paper from the laboratory of Dr. Brett Finlay at the University of British Columbia (J. van der Heijden et al., mBio 7:e01238-16, 2016, http://dx.doi...
September 27, 2016: MBio
J M Ageitos, A Sánchez-Pérez, P Calo-Mata, T G Villa
Antimicrobial peptides (AMPs) are short peptidic molecules produced by most living creatures. They help unicellular organisms to successfully compete for nutrients with other organisms sharing their biological niche, while AMPs form part of the immune system of multicellular creatures. Thus, these molecules represent biological weapons that have evolved over millions of years as a result of an escalating arms race for survival among living organisms. All AMPs share common features, such as a small size, with cationic and hydrophobic sequences within a linear or cyclic structure...
September 20, 2016: Biochemical Pharmacology
Gayathri Ravichandran, Venkatesh Kumaresan, Mariadhas Valan Arasu, Naif Abdullah Al-Dhabi, Munuswamy-Ramanujam Ganesh, Arun Mahesh, Arunkumar Dhayalan, Mukesh Pasupuleti, Jesu Arockiaraj
The antimicrobial peptides (AMPs) are multifunctional molecules which represent significant roles in the innate immune system. These molecules have been well known for decades because of their role as natural antibiotics in both invertebrates and vertebrates. The development of multiple drug resistance against conventional antibiotics brought a greater focus on AMPs in recent years. The cationic peptides, in particular, proven as host defense peptides and are considered as effectors of innate immunity. Among the various innate immune molecules, functions of pellino-1 (Peli-1) have been recently studied for its remarkable role in specific immune functions...
October 2016: Molecular Immunology
Marc Kvansakul, Fung T Lay, Christopher G Adda, Prem K Veneer, Amy A Baxter, Thanh Kha Phan, Ivan K H Poon, Mark D Hulett
Defensins are cationic antimicrobial peptides that serve as important components of host innate immune defenses, often by targeting cell membranes of pathogens. Oligomerization of defensins has been linked to their antimicrobial activity; however, the molecular basis underpinning this process remains largely unclear. Here we show that the plant defensin NsD7 targets the phospholipid phosphatidic acid (PA) to form oligomeric complexes that permeabilize PA-containing membranes. The crystal structure of the NsD7-PA complex reveals a striking double helix of two right-handed coiled oligomeric defensin fibrils, the assembly of which is dependent upon the interaction with PA at the interface between NsD7 dimers...
October 4, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jeffrey A Melvin, Ronald C Montelaro, Jennifer M Bomberger
No abstract text is available yet for this article.
November 2016: Expert Review of Anti-infective Therapy
Michaela Wenzel, Pascal Prochnow, Catherine Mowbray, Cuong Vuong, Stefan Höxtermann, Jennifer J Stepanek, H Bauke Albada, Judith Hall, Nils Metzler-Nolte, Julia E Bandow
RWRWRW-NH2 (MP196) is an amphipathic hexapeptide that targets the bacterial cytoplasmic membrane and inhibits cellular respiration and cell wall synthesis. In previous studies it showed promising activity against Gram-positive bacteria and no significant cytotoxicity or hemolysis. MP196 is therefore used as lead structure for developing more potent antibiotic derivatives. Here we present a more comprehensive study on the parent peptide MP196 with regard to clinically relevant parameters. We found that MP196 acts rapidly bactericidal killing 97% of initial CFU within 10 min at two times MIC...
2016: Frontiers in Cell and Developmental Biology
Ming Yang, Chunye Zhang, Xuehan Zhang, Michael Z Zhang, George E Rottinghaus, Shuping Zhang
BACKGROUND: Avian beta-defensins (AvBD) are small, cationic, antimicrobial peptides. The potential application of AvBDs as alternatives to antibiotics has been the subject of interest. However, the mechanisms of action remain to be fully understood. The present study characterized the structure-function relationship of AvBD-6 and AvBD-12, two peptides with different net positive charges, similar hydrophobicity and distinct tissue expression profiles. RESULTS: AvBD-6 was more potent than AvBD-12 against E...
2016: BMC Microbiology
Stephan L Grage, Sergii Afonin, Sezgin Kara, Gernot Buth, Anne S Ulrich
Membrane thinning has been discussed as a fundamental mechanism by which antimicrobial peptides can perturb cellular membranes. To understand which factors play a role in this process, we compared several amphipathic peptides with different structures, sizes and functions in their influence on the lipid bilayer thickness. PGLa and magainin 2 from X. laevis were studied as typical representatives of antimicrobial cationic amphipathic α-helices. A 1:1 mixture of these peptides, which is known to possess synergistically enhanced activity, allowed us to evaluate whether and how this synergistic interaction correlates with changes in membrane thickness...
2016: Frontiers in Cell and Developmental Biology
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