Role of Enzyme-Enzyme Interactions in the Regulation of Glycolysis

Particulate preparations obtained from a number of tissues, including liver, kidney, and muscle inactivated renal D- fructose 1,6-diphosphatase when they were incubated with the enzyme in the presence of adenosine triphosphate, magnesium ion, and cysteine.Purified swine kidney D- fructose 1,6diphosphatase and rat kidney uridine diphosphate-D-glucose-glycogen glucosyltransferase were inactivated by washed rat kidney cortex mitochondria.The initial rate of the reaction was dependent on the concentration of mitochondria, D-fructose 1,6diphosphatase, and adenosine nucleotides, and magnesium ion and cysteine were required for maximum activity.The rate of inactivation of the enzyme by mitochondria was stimulated by the addition of adenosine diphosphate and adenosine monophosphate and to a lesser extent by adenosine triphosphate.The addition of malate and succinate to the incubation mixture decreased the rate of inactivation.Under the experimental conditions used in this study the rate of inactivation was approximately 1.1 X 1O-3 pmole of D-fructose 1,6-diphosphatase per min per g of tissue.The synthesis of glycogen and glucose from noncarbohydrate precursors such as lactate, pyruvate, and amino acids is known to occur in kidney cortex.