Insights into conformation and membrane interactions of the acyclic and dicarba-bridged brevinin-1BYa antimicrobial peptides.

Insights into conformation and membrane interactions of the acyclic and dicarba-bridged brevinin-1BYa antimicrobial peptides. Eur Biophys J. 2019 Sep 12;: Authors: Timmons PB, O'Flynn D, Conlon JM, Hewage CM Abstract Brevinin-1BYa is a 24-amino acid residue host-defense peptide, first isolated from skin secretions of the foothill yellow-legged frog Rana boylii. The peptide is of interest, as it shows broad-spectrum antimicrobial activity, and is particularly effective against opportunistic yeast pathogens. Its potential for clinical use, however, is hindered by its latent haemolytic activity. The structures of two analogues, the less haemolytic [C18S,C24S]brevinin-1BYa and the more potent cis-dicarba-brevinin-1BYa, were investigated in various solution and membrane-mimicking environments by [Formula: see text] spectroscopy and molecular modelling techniques. Neither peptide possesses a secondary structure in aqueous solution. In both the membrane-mimicking sodium dodecyl sulphate micelles and 33% 2,2,2-trifluoroethanol ([Formula: see text] solvent mixture, the peptides' structures are characterised by two [Formula: see text]-helices connected by a flexible hinge located at the [Formula: see text] residues. With the aid of molecular dynamics simulations and paramagnetic probes, it was determined that the peptides' helical segments lie parallel to the micellar surface, with their hydrophobic residues facing towards the micelle core and...
Source: European Biophysics Journal : EBJ - Category: Physics Authors: Tags: Eur Biophys J Source Type: research