The Role of Phospholipids in the Activity of A⁴-3-KET₀Steroid 5α-Oxidoreductase of the Rat Ventral Prostate

Abstract

The involvement of phospholipids in the activity of 5α-reductase from nuclear and microsomal fractions of rat prostate was studied using phospholipases A and C. Phospholipase A reduced the activity of 5α-reductase in both subcellular fractions; this effect was not attributable to the hydrolysis products. Phospholipase C stopped only the activity of the nuclear fraction. There was no quantitative correlation between hydrolysis of phospholipids and loss of enzyme activity. The inactivation observed seems to result from phospholipase-induced instability of the enzyme. The results suggest that the altered structure of phospholipids and/or the membranes where 5α-reductase is located is responsible for the decrease in activity.