Mechanism of Action of Nikkomycin and the Peptide Transport System of Candida albicans

Abstract
Nikkomycin was a potent growth inhibitor of C. albicans through competitive inhibition of chitin synthase [Ki = 0.16 .mu.M (0.1 ml-1)]. The activity of the peptide-nucleoside drug was antagonized by both peptone and defined peptides. Transported dipeptides were effective antagonists while transported oligopeptides were not. A mutant of C. albicans resistant to the effects of nikkomycin through a transport defect was unable to transport dipeptides, while oligopeptide uptake was apparently unaffected. At least 2 peptide permeases are operational in this organism.