The cytochrome P450-containing monooxygenase of Trichosporon cutaneum: occurrence and properties

Abstract

Trichosporon cutaneum metabolizes glucose purely oxidatively and cytochrome P450 was not detected in the reduced CO-difference spectrum of whole cells. However, in the isolated microsomal fraction the corresponding monooxygenase was present as shown by the appearance of cytochrome P450, NADPH-cytochrome c(P450) reductase and cytochrome b5. The absorption maximum of the terminal oxidase in the reduced CO-difference spectrum shifted between 447 and 448 nm. Derepression of biosynthesis of all components was achieved by transition of the cells from carbon- to oxygen-limited growth in continuous culture. The monooxygenase exhibited aminopyrine demethylation activity but not omega-hydroxylation activity of lauric acid. With respect to the growth limiting nutrient (carbon and oxygen respectively), mitochondrial cytochrome content showed an analogous behavior as cytochrome P450 and cytochrome b5.