Enhancement of the reconstituted glucose transport activity from LM cells by phosphatidylethanolamine

The glucose transport activity from LM cells was solubilized with sodium cholate and reconstituted into liposomes containing phospholipids of varied polar head group composition. The reconstituted vesicles exhibited time-dependent preferential uptake of D- versus L-glucose. Phloretin and mercuric chloride, known inhibitors of glucose transport in the intact cells, inhibited the reconstituted transport activity. The transport activity was found to be sensitive to the phospholipid composition of the reconstituted vesicles. Proteoliposomes containing phosphatidylethanolamine showed increased transport activity. In addition, incubation of reconstituted vesicles containing phosphatidylcholine with phospholipase D plus ethanolamine resulted in vesicles containing phosphatidylcholine plus phosphatidylethanolamine and increased transport activity. These results indicate that the glucose transport system of LM cells is sensitive to polar head group structure of the phospholipids.