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cationic antimicrobial peptide

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https://www.readbyqxmd.com/read/29348804/lysine-analogue-of-polymyxin-b-as-a-significant-opportunity-for-photodynamic-antimicrobial-chemotherapy
#1
Florent Le Guern, Tan-Sothea Ouk, Catherine Ouk, Regis Vanderesse, Yves Champavier, Emilie Pinault, Vincent Sol
In order to highlight the potential of photodynamic antimicrobial chemotherapy in case of infections by antibiotic resistant-strains, a new antimicrobial peptide conjugate has been synthesized, consisting of a derivative of polymyxin B and a cationic porphyrin covalently attached together to a spacer. A polymyxin-derived moiety was subjected to a primary structural modification in the replacement of four diaminobutyrate residues with lysine ones. This modification was done in order to strongly reduce bactericidal activity, with the aim to eliminate the potential rise of polymyxin-resistant strains...
January 11, 2018: ACS Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/29347628/opposing-effects-of-cationic-antimicrobial-peptides-and-divalent-cations-on-bacterial-lipopolysaccharides
#2
Matthew Smart, Aruna Rajagopal, Wing-Ki Liu, Bae-Yeun Ha
The permeability of the bacterial outer membrane, enclosing Gram-negative bacteria, depends on the interactions of the outer, lipopolysaccharide (LPS) layer, with surrounding ions and molecules. We present a coarse-grained model for describing how cationic amphiphilic molecules (e.g., antimicrobial peptides) interact with and perturb the LPS layer in a biologically relevant medium, containing monovalent and divalent salt ions (e.g., Mg^{2+}). In our approach, peptide binding is driven by electrostatic and hydrophobic interactions and is assumed to expand the LPS layer, eventually priming it for disruption...
October 2017: Physical Review. E
https://www.readbyqxmd.com/read/29338238/paralithocins-antimicrobial-peptides-with-unusual-disulfide-connectivity-from-the-red-king-crab-paralithodes-camtschaticus
#3
Morten K Moe, Tor Haug, Magne O Sydnes, Sigmund V Sperstad, Chun Li, Lena C Vaagsfjord, Enrique de la Vega, Klara Stensvåg
As part of an ongoing exploration of marine invertebrates as a source of new antimicrobial peptides, hemocyte extracts from the red king crab, Paralithodes camtschaticus, were studied. Three cationic cysteine (Cys)-rich peptides, named paralithocins 1-3, were isolated by bioassay-guided purification, and their amino acid sequences determined by Edman degradation and expressed sequences tag analysis. Disulfide bond mapping was performed by high-resolution tandem mass spectrometry. The peptides (38-51 amino acids in length) share a unique Cys motif composed of eight Cys, forming four disulfide bridges with a bond connectivity of (Cys relative position) Cys1-Cys8, Cys2-Cys6, Cys3-Cys5, and Cys4-Cys7, a disulfide arrangement that has not been previously reported among antimicrobial peptides...
January 17, 2018: Journal of Natural Products
https://www.readbyqxmd.com/read/29337270/the-cationic-tetradecapeptide-mastoparan-as-a-privileged-structure-for-drug-discovery-enhanced-antimicrobial-properties-of-mitoparan-analogues-modified-at-position-14
#4
John Howl, Lewis Howl, Sarah Jones
Mastoparan (MP) peptides, distributed in insect venoms, induce a local inflammatory response post envenomation. Most endogenous MPs share common structural elements within a tetradecapeptide sequence that adopts an amphipathic helix whilst traversing biological membranes and when bound to an intracellular protein target. Rational modifications to increase cationic charge density and amphipathic helicity engineered mitoparan (MitP), a mitochondriotoxic bioportide and potent secretagogue. Following intracellular translocation, MitP is accreted by mitochondria thus indicating additional utility as an antimicrobial agent...
January 11, 2018: Peptides
https://www.readbyqxmd.com/read/29329747/antibacterial-properties-of-latarcin-1-derived-cell-penetrating-peptides
#5
Deepthi Poornima Budagavi, Archana Chugh
Cell-penetrating peptides (CPPs) and antimicrobial peptides (AMPs) share certain physicochemical parameters such as amphipathicity, hydrophobicity, cationicity and pI, due to which these two groups of peptides also exhibit overlapping functional characteristics. In our current work, we have evaluated antimicrobial properties of cell-penetrating peptides derived from Latarcin1. Latarcin derived peptide (LDP) exhibited antimicrobial activity against representative microorganisms tested and bactericidal effect against methicillin resistant Staphylococcus aureus (MRSA), which was used as model organism of study in the present work...
January 9, 2018: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/29315029/correlations-among-resistances-to-different-antimicrobial-compounds-in-salmonella-strains-from-hen-eggshells
#6
Maria Luisa Fernández Márquez, María José Grande Burgos, Rubén Pérez Pulido, Antonio Gálvez, Rosario Lucas López
Persistence of antibiotic-resistant Salmonella in the food chain may depend on strain tolerance to other antimicrobials and also on biofilm formation capacity. Yet, there is limited information on sensitivity of antibiotic-resistant Salmonella to other antimicrobials, such as phenolic compounds, chemical preservatives, or antimicrobial peptides. This study aimed at correlating antimicrobial resistance and biofilm formation capacity in antibiotic-resistant, biocide-tolerant Salmonella strains from hen eggshells...
February 2018: Journal of Food Protection
https://www.readbyqxmd.com/read/29301331/antimicrobial-and-antibiofilm-activity-of-up-5-an-ultrashort-antimicrobial-peptide-designed-using-only-arginine-and-biphenylalanine
#7
Ammar Almaaytah, Mohammed T Qaoud, Gubran Khalil Mohammed, Ahmad Abualhaijaa, Daniel Knappe, Ralf Hoffmann, Qosay Al-Balas
The recent upsurge of multidrug resistant bacteria (MDRB) among global communities has become one of the most serious challenges facing health professionals and the human population worldwide. Cationic ultrashort antimicrobial peptides (USAMPs) are a promising group of molecules that meet the required criteria of novel antimicrobial drug development. UP-5, a novel penta-peptide, displayed significant antimicrobial activities against various standard and clinical isolates of MDRB. UP-5 displayed MICs values within the range of (10-15 μM) and (55-65 μM) against Gram-positive and Gram-negative bacteria, respectively...
January 2, 2018: Pharmaceuticals
https://www.readbyqxmd.com/read/29284086/the-antimicrobial-peptide-k0-w6-hya1-induces-stable-structurally-modified-lipid-domains-in-anionic-membranes
#8
Thais Azevedo Enoki, Isabela Moreira-Silva, Esteban N Lorenzon, Eduardo Maffud Maffud Cilli, Katia Regina Perez, Karin A Riske, M Teresa Lamy
Considering the known different mode of action of antimicrobial peptides in zwitterionic and anionic cell membranes, the present work compares the action of the antimicrobial peptide K0-W6-Hya1 (KIFGAIWPLALGALKNLIK-NH2) with zwitterionic and negatively charged model membranes, namely, liposomes composed of phosphatidylcholine (PC) and phosphatidylglycerol (PG) membranes, and a mixture of the two. Differential Scanning Calorimetry (DSC), steady state fluorescence of the Trp residue, Dynamic Light Scattering (DLS) and the measurement of the leakage of an entrapped fluorescent dye (carboxyfluorescein, CF) were performed with large unilamellar vesicles (LUVs)...
December 28, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29275987/influence-of-hydrocarbon-stapling-on-membrane-interactions-of-synthetic-antimicrobial-peptides
#9
Tracy A Stone, Gregory B Cole, Huong Q Nguyen, Simon Sharpe, Charles M Deber
Cyclization has been recognized as a valuable technique for increasing the efficacy of small molecule and peptide therapeutics. Here we report the application of a hydrocarbon staple to a rationally-designed cationic antimicrobial peptide (CAP) that acquires increased membrane targeting and interaction vs. its linear counterpart. The previously-described CAP, 6K-F17 (KKKKKK-AAFAAWAAFAA-NH2) was used as the backbone for incorporation of an i to i + 4 helical hydrocarbon staple through olefin ring closing metathesis...
October 21, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/29273750/elimination-of-antibiotic-resistant-surgical-implant-biofilms-using-an-engineered-cationic-amphipathic-peptide-wlbu2
#10
Jonathan B Mandell, Berthony Deslouches, Ronald C Montelaro, Robert M Q Shanks, Yohei Doi, Kenneth L Urish
Antibiotics are unable to remove biofilms from surgical implants. This high antibiotic tolerance is related to bacterial persisters, a sub-population of bacteria phenotypically tolerant to antibiotics secondary to a reduced metabolic state. WLBU2 is an engineered cationic amphipathic peptide designed to maximize antimicrobial activity with minimal mammalian cell toxicity. The objective of this study was to test the ability of WLBU2 to remove Staphylococcus aureus surgical implant biofilms. WLBU2 effectively treated S...
December 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29259246/structure-and-interactions-of-a%C3%A2-host-defense-antimicrobial-peptide-thanatin-in-lipopolysaccharide-micelles-reveal-mechanism-of-bacterial-cell-agglutination
#11
Sheetal Sinha, Liangzhen Zheng, Yuguang Mu, Wun Jern Ng, Surajit Bhattacharjya
Host defense cationic Antimicrobial Peptides (AMPs) can kill microorganisms including bacteria, viruses and fungi using various modes of action. The negatively charged bacterial membranes serve as a key target for many AMPs. Bacterial cell death by membrane permeabilization has been well perceived. A number of cationic AMPs kill bacteria by cell agglutination which is a distinctly different mode of action compared to membrane pore formation. However, mechanism of cell agglutinating AMPs is poorly understood...
December 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29250064/p17-an-original-host-defense-peptide-from-ant-venom-promotes-antifungal-activities-of-macrophages-through-the-induction-of-c-type-lectin-receptors-dependent-on-ltb4-mediated-ppar%C3%AE-activation
#12
Khaddouj Benmoussa, Hélène Authier, Mélissa Prat, Mohammad AlaEddine, Lise Lefèvre, Mouna Chirine Rahabi, José Bernad, Agnès Aubouy, Elsa Bonnafé, Jérome Leprince, Bernard Pipy, Michel Treilhou, Agnès Coste
Despite the growing knowledge with regard to the immunomodulatory properties of host defense peptides, their impact on macrophage differentiation and on its associated microbicidal functions is still poorly understood. Here, we demonstrated that the P17, a new cationic antimicrobial peptide from ant venom, induces an alternative phenotype of human monocyte-derived macrophages (h-MDMs). This phenotype is characterized by a C-type lectin receptors (CLRs) signature composed of mannose receptor (MR) and Dectin-1 expression...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/29233222/understanding-membrane-active-antimicrobial-peptides
#13
Huey W Huang, Nicholas E Charron
Bacterial membranes represent an attractive target for the design of new antibiotics to combat widespread bacterial resistance to traditional inhibitor-based antibiotics. Understanding how antimicrobial peptides (AMPs) and other membrane-active agents attack membranes could facilitate the design of new, effective antimicrobials. AMPs, which are small, gene-encoded host defense proteins, offer a promising basis for the study of membrane-active antimicrobial agents. These peptides are cationic and amphipathic, spontaneously binding to bacterial membranes and inducing transmembrane permeability to small molecules...
January 2017: Quarterly Reviews of Biophysics
https://www.readbyqxmd.com/read/29232144/interactions-between-surface-immobilized-antimicrobial-peptides-and-model-bacterial-cell-membranes
#14
Xiaofeng Han, Jingguo Zheng, Fengming Lin, Kenichi Kuroda, Zhan Chen
Sum frequency generation vibrational spectroscopy (SFG) was used to study surface immobilization effects on the interactions between antimicrobial peptide (AMP) cecropin P1 (CP1) and model cell membranes. While free CP1 in solution interacted with a model cell membrane composed of a phosphatidylglycerole (PG) bilayer, electrostatic interaction led to the attachment of the CP1 molecules onto the PG surface, and the hydrophobic domain in the lipid bilayer enabled the peptides to insert into the bilayer and form α-helices from random coil structures...
December 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29227931/synthesis-and-antibacterial-evaluation-of-novel-cationic-chalcone-derivatives-possessing-broad-spectrum-antibacterial-activity
#15
Wen-Chao Chu, Peng-Yan Bai, Zhao-Qing Yang, De-Yun Cui, Yong-Gang Hua, Yi Yang, Qian-Qian Yang, En Zhang, Shangshang Qin
There is an urgent need to identify new antibiotics with novel mechanisms that combat antibiotic resistant bacteria. Herein, a series of chalcone derivatives that mimic the essential properties of cationic antimicrobial peptides were designed and synthesized. Antibacterial activities against drug-sensitive bacteria, including Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Salmonella enterica, as well as clinical multiple drug resistant isolates of methicillin-resistant S. aureus (MRSA), KPC-2-producing and NDM-1-producing Carbapenem-resistant Enterobacteriaceae were evaluated...
December 5, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29211886/bicarbonate-induces-high-level-resistance-to-the-human-antimicrobial-peptide-ll-37-in-staphylococcus-aureus-small-colony-variants
#16
Ping Zhang, John A Wright, Anna Tymon, Sean P Nair
Objectives: Staphylococcus aureus small colony variants (SCVs) cause persistent infections and are resistant to cationic antibiotics. Antimicrobial peptides (AMPs) have been suggested as promising alternatives for treating antibiotic-resistant bacteria. We investigated the capacity of the human cationic AMP LL-37 to kill SCVs in the presence of physiological concentrations of bicarbonate, which are reported to alter bacterial membrane permeability and change resistance of bacteria to AMPs...
December 4, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/29208497/molecular-cloning-expression-promoter-analysis-and-functional-characterization-of-a-new-crustin-from-litopenaeus-vannamei
#17
Ming Li, Chunxia Ma, Haoyang Li, Jinxia Peng, Digang Zeng, Xiaohan Chen, Chaozheng Li
Antimicrobial peptides (AMPs) are the most important players in the innate immune system, providing a principal first-line of defense against the invading pathogens. Crustin, a type of whey acidic protein (WAP) domain-containing and cationic cysteine-rich AMP, can function in a protease inhibition or an effector molecule manner. In the present study, a new Crustin was cloned and identified from Pacific white shrimp Litopenaeus vannamei and designated as LvCrustinA. The full-length cDNA of LvCrustinA was 687 bp, with a 519 bp open reading frame (ORF) that encoded a peptide of 172 amino acids...
December 5, 2017: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/29204423/dual-coating-of-liposomes-as-encapsulating-matrix-of-antimicrobial-peptides-development-and-characterization
#18
Ahmed I Gomaa, Cynthia Martinent, Riadh Hammami, Ismail Fliss, Muriel Subirade
Antimicrobial peptides have been proposed as a potential biopreservatives in pharmaceutical research and agribusiness. However, many limitations hinder their utilization, such as their vulnerability to proteolytic digestion and their potential interaction with other food ingredients in complex food systems. One approach to overcome such problems is developing formulations entrapping and thereby protecting the antimicrobial peptides. Liposome encapsulation is a strategy that could be implemented to combine protection of the antimicrobial activity of the peptides from proteolytic enzymes and the controlled release of the encapsulated active ingredients...
2017: Frontiers in Chemistry
https://www.readbyqxmd.com/read/29198866/effect-of-side-chain-hydrophobicity-and-cationic-charge-on-antimicrobial-activity-and-cytotoxicity-of-helical-peptoids
#19
Jiyoun Lee, Dahyun Kang, Jieun Choi, Wei Huang, Mayken Wadman, Annelise E Barron, Jiwon Seo
Peptoids are peptidomimetic polymers that are resistant to proteolysis and less prone to immune responses; thus, they can provide a practical alternative to peptides. Among the various therapeutic applications that have been explored, cationic amphipathic peptoids have demonstrated broad-spectrum antibacterial activity, including activity towards drug-resistant bacterial strains. While their potency and activity spectrum can be manipulated by sequence variations, bacterial selectivity and systemic toxicity need to be improved for further clinical development...
November 23, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/29196622/intracellular-biomass-flocculation-as-a-key-mechanism-of-rapid-bacterial-killing-by-cationic-amphipathic-antimicrobial-peptides-and-peptoids
#20
Nathaniel P Chongsiriwatana, Jennifer S Lin, Rinki Kapoor, Modi Wetzler, Jennifer A C Rea, Maruti K Didwania, Christopher H Contag, Annelise E Barron
Many organisms rely on antimicrobial peptides (AMPs) as a first line of defense against pathogens. In general, most AMPs are thought to kill bacteria by binding to and disrupting cell membranes. However, certain AMPs instead appear to inhibit biomacromolecule synthesis, while causing less membrane damage. Despite an unclear understanding of mechanism(s), there is considerable interest in mimicking AMPs with stable, synthetic molecules. Antimicrobial N-substituted glycine (peptoid) oligomers ("ampetoids") are structural, functional and mechanistic analogs of helical, cationic AMPs, which offer broad-spectrum antibacterial activity and better therapeutic potential than peptides...
December 1, 2017: Scientific Reports
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