The research is concerned with aspects of the lipid metabolism of plasma lipoproteins and the proteins of erythrocyte membranes. Current studies are focused primarily on characterization of the membrane protein spectrin, its organization in the membrane, its interaction with other membrane proteins and membrane lipids, its phosphorylation by membrane protein kinases, its role in control of membrane shape and deformability, and its derangement in various inherited and acquired membrane defects resulting in hemolytic anemia. Ongoing projects also include studies of the topography of membrane proteins, identification and characterization of membrane protein defects involving proteins other than spectrin, and identification and characterization of lipid-binding regions of plasma and membrane apolipoproteins. BIBLIOGRAPHIC REFERENCES: Breslow, J.L., Lothrop, D.A., Clowes, A.W. and Lux, S.E.: Lipoprotein regulation of 3-hydroxy-methyl glutaryl coenzyme, a reductase activity in rat liver cell cultures. J. Biol. Chem. 252: 2726-2733, 1977. Lux, S.E. and John, K.M.: Isolation and partial characterization of a high molecular weight membrane protein from erythrocytes of asplenic patients. Blood. (In press, 1977).