The interaction of amphotericin B methyl ester with protoplasts of Candida albicans

The interaction of amphotericin B methyl ester (AME) with protoplasts of Candida albicans was measured indirectly by following the incorporation of [U-14C]phenylalanine into the acid-insoluble material. The inhibitory effects of AME at the minimum inhibitory concentration were prevented by the addition of 85 mM-KCl and 45 mM-MgCl2, as shown by Liras & Lampen (1974) for Saccharomyces cerevisiae. In C. albicans, pretreatment of the yeast before anti-biotic addition was unnecessary. KCl and MgCl2 did not prevent AME from binding to the protoplast membrane. This interaction was reversed by incubating the protoplasts in the presence of the protecting salts.