The Mode of Action of Polyene Antibiotics; Induced Entry of Hydrogen Ions as a Consequence of Polyene Action on the Cell Membrane of Candida albicans

Summary: The polyene antibiotic candicidin is a potent antifungal agent acting upon the cell membrane of Candida albicans. Destruction of selective permeability by polyenes allows cations to leak into the environment and permits the entry of protons to neutralize the charge so created, causing internal acidification. Quantitive studies on proton entry reveal that K+ leakage alone is not sufficient to account for the degree of acidification recorded. Extracts of untreated C. albicans, when acidified to the same extent, precipitated. Electron micrographs of candicidin treated C. albicans cells confirm this precipitation.