The basic aim of the proposed research is to obtain an understanding of the function of alpha-glycerol phosphate dehydrogenase (GPDH) in metabolism and to elucidate the mechanisms of integration of lipid and carbohydrate metabolism in mammalian organisms. Ion-exchange and affinity chromatography techniques will be applied to the isolation of rabbit heart GPDH. Characterization of the heart muscle enzyme will involve a determination of the catalytic constants, amino acid composition and the effect of modifiers on the enzymic activity. The effect of hydrophobic molecules on the enzymes isolated from rabbit skeletal muscle, heart and liver will be studied with the aim of probing (a) the nature of the hydrophobic binding site on the three enzymes, (b) the nature of the differences between the responses of the enzymes, and (c) the effect of different classes of lipids on the enzyme activity and its possible physiological significance. These studies of the types of interactions between the enzyme, it substrates and its activators and inhibitors will lead to the development of a model for predicting the effect of various lipids on the enzyme under a diverse range of conditions. BIBLIOGRAPHIC REFERENCES: Affinity Purification of alpha-Glycerol Phosphate Dehydrogenase, R. A. MacQuarrie, D. J. McLoughlin and D. Terry. 12th Midwest Regional ACS Meeting, Oct. 28-29, 1976. The Purification and the Effect of Lipids on Rabbit Liver alpha-Glycerol Phosphate Dehydrogenase, D. J. McLoughlin and R. A. MacQuarrie, FASEB, April 1977.