Physiological and biochemical analysis of cytochrome P‐450 in the yeast Schizosaccharomyces pombe

The yeast Schizosacchromyces pombe has been shown to contain a microsomal cytochrome P‐450 (cyt. P‐450) inducible under conditions of glucose repression. Under these conditions the enzyme has maximal expression of 0.43 nmol g −1 wet wt at the end of the exponential phase of growth. Substrate and inhibitor affinity was examined using studies of spectral changes on binding and revealed a type II spectrum with ketoconazole ( K s = 23 μ M ) and a type I spectrum with benzo(a)pyrene ( K s = 77 μ M ). A K m of 112 μ M was found in the aryl hydrocarbon hydroxylas assay. These properties show broad comparability with the cyt. P‐450 of Saccharomyces cerevisiae .