Factors that are important in preventing the inactivation of hexokinase II and other enzymes that are insulin regulated will be studied using whole cell systems, extracts and isolated enzymes. Factors responsible for the reductive reactivation of hexokinase in vitro will be studied. Glucose and K ion, both of which stabilize hexokinase II and which rise in tissues in response to insulin (and decrease due to fasting and glucagon) will be examined as possible effectors of the stability of other responsive glycolytic enzymes (phosphofructokinase and pyruvate kinase) and lipogenic enzymes (ATP citrate lyase, malic enzyme and acetyl CoA carboxylase) of the liver using methods to alter intracellular K ion levels.