13] Specific radioimmunoassays for rabbit liver fructose bisphosphatase, pyruvate kinase, and glycerol-3-phosphate dehydrogenase

Abstract

This chapter discusses the specific radioimmunoassays (RIAs) for rabbit liver fructose bisphosphatase, pyruvate kinase, and glycerol-3-phosphate dehydrogenase. The enzymes have in common the fact that all five are soluble, cytosolic enzymes of glucose utilization or formation. It is found that, with respect to size, stability, kinetic behavior and regulation, structure, and other features, they differ greatly. The differences made it necessary to tailor one or more steps of each RIA method to that enzyme. It is found that, with an RIA, one can establish to what extent the liver regulates the flux of carbon in a reaction, by changing the mass of the enzyme. It is found that, with the RIA and assayable activity assay, one can also establish the extent, to which the liver regulates the flux of carbon in a reaction, by changing the catalytic quality of the enzyme. The accuracy of the data depends largely on the specificity and design of the RIA methods. A major test of accuracy rests on favorable comparisons of specific activity values is determined independently.