SUBSTRATE SPECIFICITY OF 17b bb b-HYDROXYSTEROID DEHYDROGENASE FROM PLEUROTUS OSTREATUS

M. Pogaèar. M. Zorko and M. Žakelj-Mavriè Institute of Biochemistry, Medical Faculty, Ljubljana, Slovenia

We present evidence which suggests that Pleurotus ostreatus 17(beta)-HSD is a pluripotent enzyme which can oxidize 17(beta)-hydroxysteroids and even more so hydroquinone in the presence of NAD + . The study of the reverse reaction indicates that the carbonyl reductase activity prevails over the hydroxysteroid dehydrogenase activity. Kinetic studies also reveal the presence of a separate acetoacetyl CoA reductase / (beta)-hydroxybutyryl CoA dehydrogenase activity in Pleurotus ostreatus.