Selective interaction of D-beta-hydroxybutyrate dehydrogenase with intracellular membranes

Abstract

We are investigating the properties of pre-existing membrane structures that may contribute to localization of newly formed polypeptides on target membranes. To this end, D-beta-hydroxybutyrate dehydrogenase (EC 1.1.1.30) was purified from inner membranes of rat liver mitochondria and interacted with three different cellular membranes, as well as with liposomes prepared from membrane lipid extracts. (1) The purified lipid-free enzyme displayed little catalytic activity. Its activity was restored by interaction with rat liver mitochondrial inner membranes or microsomal membranes, but not with rat erythrocyte plasma membrane vesicles. (2) Plasma membranes from which membrane proteins had been partially removed did not reactivate the enzyme, but microsomal membranes treated in a similar manner displayed an increased efficiency of reactivation. (3) The selective reactivation found in the three membrane species was confirmed in liposomes prepared with total lipid extracts of the native membranes. The results suggest that the interaction of exogeneously added enzyme with the membranes is primarily dependent on lipid components or some specific lipid environment on the acceptor membranes.