Characterization of the polyene macrolide P450 epoxidase from Streptomyces natalensis that converts de-epoxypimaricin into pimaricin.

ABSTRACT: The biosynthesis of the antifungal agent pimaricin by Streptomyces natalensis has been proposed to involve a cytochrome P450 encoded by the gene pimD. Pimaricin is derived from its immediate precursor de-epoxypimaricin by epoxidation of the C-4-C-5 double bond on the macrolactone ring. We have overproduced PimD with a N-terminal His6 affinity tag in Escherichia coli and purified the enzyme for kinetic analysis. The protein showed a reduced CO-difference spectrum with a Soret maximum at 450 nm, indicating that it is a cytochrome P450. Purified PimD was shown to catalyse the in vitro C-4-C-5 epoxidation of 4,5-de-epoxypimaricin to pimaricin. The enzyme was dependent on NADPH for activity with optimal pH at 7.5, and the temperature optimum was 30 degrees C. The kcat value for the epoxidation

SUBMITTER: Mendes MV 

PROVIDER: S-EPMC1134766 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature