The regulatory properties of yeast pyruvate kinase

The regulatory properties of yeast pyruvate kinase.

The kinetics of pyruvate kinase from Saccharomyces cerevisiae were studied in assays at pH 6.2 where the relationships between the initial velocities of the catalysed reaction and the concentrations of the substrates ADP, phosphoenolpyruvate and Mg2+ are non-hyperbolic. The findings were represented empirically by the exponential model for a regulatory enzyme. The analysis shows that ADP, phosp...

Regulatory Properties of Skeletal-Muscle Pyruvate Kinase

Hitherto it has been generally supposed that pyruvate kinase (EC 2.7.1.40) has no significant role in the regulation in vivo of glycolytic flux in skeletal muscle (Carbonell et al., 1973). This supposition, apart from providing an explanation for the apparent lack of potentially regulatory allosteric interactions by skeletal-muscle (M-type) pyruvate kinase, is in agreement with the idea that gl...

The regulatory properties of yeast pyruvate kinase. Effect of fructose 1,6-bisphosphate.

The kinetics of pyruvate kinase from Saccharomyces cerevisiae were studied in assays at pH 6.2 at 25 degrees C as a function of the concentrations of the substrates ADP, phosphoenolpyruvate and Mg2+ and the concentration of the effector fructose 1,6-bisphosphate. The enzyme was activated by 100 mM-K+ and 32 mM-NH4+ throughout. It was found that an increase in the fructose bisphosphate concentra...

Yeast Pyruvate Kinase

The kinetic properties of purified yeast pyruvate kinase were investigated. The enzyme showed cooperative kinetics toward the essential activating monovalent cations K+ and NH4+, Mg2+, and phosphoenolpyruvate. Fructose 1,6diphosphate, which yielded homotropic cooperative kinetics and did not affect maximal velocity, transformed the sigmoidal kinetics of Kf and NH4+, Mgz+, and phosphoenolpyruvat...

Yeast pyruvate kinase. I. Purification and some chemical properties.