A kinetic study of baker's-yeast pyruvate kinase activated by fructose 1,6-diphosphate |
| |
Authors: | Neil Macfarlane and Stanley Ainsworth |
| |
Institution: | Department of Biochemistry, University of Sheffield, Sheffield S10 2TN, U.K. |
| |
Abstract: | 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. |
| |
Keywords: | |
|
|