The antimicrobial activity of hexapeptides derived from synthetic combinatorial libraries

A series of peptides identified through the use of synthetic hexapeptide combinatorial libraries (represented by the formula Ac-RRWWCO-NH2) were examined for their antimicrobial activity against five different micro-organisms. Their toxicity was also evaluated in an in vitro haemolytic assay. The peptides showed activity against the five micro-organisms, although higher activities were found against Gram-positive bacteria. Both growth inhibition and cell viability assays were carried out to demonstrate the bactericidal activities of these peptides against two of the micro-organisms tested. The dimeric cystine forms of these peptides were shown to have biological activities identical to the monomeric forms.