Kinetic characterization of yeast pyruvate carboxylase isozyme Pyc1 and the Pyc1 mutant, C249A

The yeast Pyc1 (pyruvate carboxylase) isoform of pyruvate carboxylase is characterized and shown to differ from the Pyc2 isoform in its K (sub a) for K (super +) activation. Kinetic measurements on the C249A mutant enzyme reveals that C249 is involved in the binding and action of enzyme activators K (super +) and acetyl-CoA.