Cysteine oxidation and annulment of amphotericin B inhibition ofCoccidioides immitis

Publisher Website
Google Scholar
Abstract
The capacity of cysteine to annul the inhibitory action of amphotericin B on Coccidioides immitis was studied. Concomitant with inhibited growth were suppressed respiration patterns. Added cysteine, however, which was not oxidized by untreated endospores, was attacked by amphotericin-treated cells; it was oxidized to cystine. A crude cysteine oxidase was obtained from endospores that had not been exposed to cysteine. Evidence is presented that exogeneous cysteine is oxidized by endospores only after amphotericin damages cell barriers. It is speculated that the resulting oxidation is an important feature in the annulment of amphotericin activity.