Purification of a soluble cytochrome P450 from Trichosporon montevideense

The yeast Trichosporon montevideense CBS 6721 expressed large amounts of cy tochrome P450 after cultivation in a glucose-peptone medium. The P450, whic h could be detected in the cytosolic fraction after cell breakage and ultra centrifugation, was purified to electrophoretic homogeneity and migrated in SDS-PAGE with a M-r of 43.000. As indicated by IEF, the preparation consis ted of two different P450 isoforms with pI-values of 5.9 and 6.2, which wer e named P45(MS1) and P45(MS2) respectively. Both isoforms had a characteris tic maximum at 446 nm in the reduced carbon monoxide difference spectra. Pa rtial N-terminal sequencing of P450(MS1) and P450(MS2) demonstrated a high degree of sequence homology between the soluble P450 enzymes of T. montevid eense CBS 6721 and their close relationship to those soluble P450 forms of Trichosporon spec. SBUG 752 T. cutaneum ATCC 58094 and to the P450s of the CYP55 family of Fusarium oxysporum and Cylindrocarpon tonkinense.