A kinetic study of Baker's-yeast pyruvate kinase activated by fructose 1,6-diphosphate.
The paper reports a study of the kinetics of the reaction between phosphoenolpyruvate, ADP and Mg(2+) catalysed by yeast pyruvate kinase when activated by fructose 1,6-diphosphate and K(+). The experimental results indicate that the reaction mechanism is of the Ordered Tri Bi type with the substrates binding in the order phosphoenolpyruvate, ADP and Mg(2+). Direct phosphoryl transfer takes place in the quaternary complex, with pyruvate released before MgATP. A dead-end enzyme-pyruvate complex is also indicated. Values have been determined for the Michaelis, dissociation and inhibition constants of the reaction. Several of the rate constants involved have also been evaluated.
D000244:Adenosine Diphosphate; D003201:Computers; D004789:Enzyme Activation; D004790:Enzyme Induction; D005636:Fructosephosphates / Q000494:pharmacology*; D007700:Kinetics; D008274:Magnesium; D010728:Phosphoenolpyruvate; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D005636:Fructosephosphates; D000244:Adenosine Diphosphate; D010728:Phosphoenolpyruvate; D011770:Pyruvate Kinase; D008274:Magnesium