MICROSOMAL AND CYTOSOLIC CYTOCHROME P450 MEDIATED BENZO(A)PYRENE HYDROXYLATION IN PLEUROTUS PULMONARIUS

摘要

Microsomal and soluble fractions of Pleurotus pulmonarius exhibited a reduced carbon monoxide difference spectrum with P450 maxima at 448nm and 450-452nm respectively. Substrate induced Type I spectra were observed on addition of benzo(a)pyrene to both fractions. Benzo(a)pyrene hydroxylation was measured using the aryl hydrocarbon hydroxylase assay and was observed to be P450 dependent as indicated by carbon monoxide inhibition together with the substrate binding characteristics. The activity of the fractions were observed to give K-m of 200mM and 660mM and V-max of 1.25 nmol/minmol P450 and 0.57 nmol/minmol P450 for the microsomal and cytosolic fractions respectively. [References: 18]