Glucolipid Synthesis Activities in Cytoplasmic and Thylakoid Membranes from the Cyanobacterium <italic>Anacystis nidulans</italic>

Abstract

Cytoplasmic membranes (plasma membranes), thylakoid membranes and cell walls prepared from the cyanobacterium, Anacystis nidulans, were compared for UDP-glucose: l,2-diacylglycerol glucosyltransferase activity. When 1,2-dipalmitoylglycerol was added as a glucosyl acceptor, both cytoplasmic membranes and thylakoid membranes incorporated glucose from UDP-glucose into monoglucosyl diacylglycerol, but the cell walls containing the outer membranes did not. The cytoplasmic membranes incorporated about twice as much glucose as the thylakoid membranes on a protein basis. These observations suggest that in A. nidulans the UDP-glucose: 1,2-diacylglycerol glucosyltransferase participating in glucolipid biosynthesis is located in both cytoplasmic and thylakoid membranes, but not in the outer membrane.