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Crystal structure of modified Gramicidin S. Modification includes Boc groups on the ornithine as well as methylation of select amide nitrogens to force cyclic conformation. [10] Gramicidin S differs from other gramicidin types in that it is a cationic cyclic decapeptide and has a structure of an anti-parallel beta-sheet.
Glycopeptide antibiotics are a class of drugs of microbial origin that are composed of glycosylated cyclic or polycyclic nonribosomal peptides.Significant glycopeptide antibiotics include the anti-infective antibiotics vancomycin, teicoplanin, telavancin, ramoplanin, avoparcin and decaplanin, corbomycin, complestatin and the antitumor antibiotic bleomycin.
Daptomycin has a distinct mechanism of action, disrupting multiple aspects of bacterial cell membrane function. It inserts into the cell membrane in a phosphatidylglycerol-dependent fashion, where it then aggregates. The aggregation of daptomycin alters the curvature of the membrane, which creates holes that leak ions.
Mechanism of action [ edit ] Alters bacterial outer membrane permeability by binding to a negatively charged site in the lipopolysaccharide layer, which has an electrostatic attraction for the positively charged amino groups in the cyclic peptide portion [ 11 ] (this site normally is a binding site for calcium and magnesium counter ions); the ...
α-Amanitin Bacitracin Ciclosporin. Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. [1] This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains ...
In many cases, the exact mechanism of killing is not known. One emerging technique for the study of such mechanisms is dual polarisation interferometry. [14] [15] In contrast to many conventional antibiotics these peptides appear to be bactericidal [2] instead of bacteriostatic. In general the antimicrobial activity of these peptides is ...
Bacitracin [1] is a polypeptide antibiotic. It is a mixture of related cyclic peptides produced by Bacillus licheniformis bacteria, that was first isolated from the variety "Tracy I" (ATCC 10716) in 1945. [2] These peptides disrupt Gram-positive bacteria by interfering with cell wall and peptidoglycan synthesis.
The name lantibiotics was introduced in 1988 as an abbreviation for "lanthionine-containing peptide antibiotics". [1] The first structures of these antimicrobial agents were produced by pioneering work by Gross and Morell in the late 1960s and early 1970s, thus marking the formal introduction of lantibiotics.