2026-10-04T06:04:09Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/121482026-09-26T00:05:32Zcom_10259_4862com_10259_5086com_10259_2604col_10259_4863

Mendes, Marta V. Antón Fidalgo, Nuria Martín, Juan F. Aparicio, Jesús F. 2005 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 °C. The kcat value for the epoxidation of de-epoxypimaricin was similar to the values reported for other macrolide oxidases. Enzyme activity was inhibited at high substrate concentration. This is the first time that a polyene macrolide P450 mono-oxygenase has been expressed heterologously and studied. The unique specificity of this epoxidase should be useful for the oxidative modification of novel polyene macrolide antibiotics. application/pdf https://hdl.handle.net/10259/12148 eng Biochemical society Characterization of the polyene macrolide P450 epoxidase from Streptomyces natalensis that converts de-epoxypimaricin into pimaricin info:eu-repo/semantics/article TEXT RIUBU. Repositorio Institucional de la Universidad de Burgos Hispana