REGULATION OF SUPEROXIDE-DISMUTASE SYNTHESIS IN CANDIDA-ALBICANS

The synthesis of superoxide dismutase [SOD: EC 1.15.1.1] in response t o various cultural conditions was examined in Candida albicans, an opp ortunistic yeast which causes candidiasis in immunosuppressed patients . SOD plays an important role in protecting cells from the oxidative d amage of superoxide radicals. Maximum SOD activity was found after 72 hrs of yeast growth. The optimum pH and temperature for the SOD activi ty were 7 and 40 degrees C, respectively. The major SOD activity was f ound in the cytosol fraction and the level of extracellular SOD was ve ry low. The enzyme was stimulated to varying degrees by cholic acid, p rocaine and tocopherol. On the basis of inhibitor studies and other en zyme properties, the isolated enzyme from C. albicans is identified as copper and zinc superoxide dismutase.