Ultraviolet Micrography of Penetration of Exogenous Cytochrome c into the Yeast Cell

Abstract

Candida utilis and Saccharomyces cerevisiae in water suspension were found to be very sensitive to exogenous cytochrome c . The protein was taken up by the cells, and the viable count was reduced to a few per cent of the initial value. Micrography at 405 nm revealed penetration of cytochrome c into the interior of the cell. The cytoplasmic membrane lost its capacity to retain intracellular constituents, and ultraviolet-absorbing compounds were released into the medium. When budding cells were subjected to treatment with cytochrome c , the mother cells were found to be more susceptible than the buds. Phosphate buffer protected the cells and spheroplasts against cytochrome c .