Chemical specificity of pyruvate kinase from yeast

Abstract

Three analogs of phosphoenolpyruvic acid: (Z)-phosphoenol-3-fluoropyruvate, (Z)-phosphoenol-3-bromopyruvate and (Z)-phosphoenol-α-ketobutyrate were found to be substrates for yeast pyruvate kinase (ATP : pyruvate (Z)-O-phosphotransferase, EC 2.7.1.40) with maximal velocities much greater than those found for rabbit muscle pyruvate kinase. The analogs exhibited sigmoidal kinetics, which become hyperbolic upon addition of the allosteric effector, fructose 1,6-diphosphate. Moreover, the reaction of (Z)-phosphoenol-3-bromopyruvate with ADP to produce bromopyruvic acid and ATP irreversibly inhibited the enzyme with a half-life of 32 min. © 1975.