David Francis Mahoney

A peptide binding chromogenic assay for detecting glycopeptide antibiotics

SummaryA solid-phase peptide binding assay, based on the mechanism of action of glycopeptide antibiotics, was developed for detecting this chemical class of metabolites. Utilizing a pentapeptide (l-alanyl-d-isoglutaminyl-l-lysyl-d-alanyl-d-alanine)-bovine serum albumin conjugate immobilized on the wall of microtiter wells, the binding of the vancomycin-alkaline phosphatase to the peptide could be demonstrated by subsequently monitoring the enzyme activity. The presence of glycopeptides in fermentation broths could be detected and quantified with a competitive binding assay. Peptides with ad-alanyl-d-alanine carboxyl terminus were necessary for the binding of these glycopeptides, thus confirming the mode of action of this class of antibiotics.