27 research outputs found
Pyruvate carboxylase from a thermophilic Bacillus. Studies on the specificity of activation by acyl derivatives of coenzyme A and on the properties of catalysis in the absence of activator
Activation of Phosphoenolpyruvate Carboxylase from Escherichia coli by Long-Chain Acyl Derivatives of Coenzyme A and by Blue Dextran 2000
The effect of EDTA on the apparent hysteretic properties of pyruvate carboxylase from Rhizopus arrhizus
The effect of EDTA on the apparent hysteretic properties of pyruvate carboxylase from Rhizopus arrhizus
AbstractPyruvate carboxylase purified from Rhizopus arrhizus in the presence of 1 mM EDTA shows markedly nonlinear progress curves when assayed in the presence of acetyl-CoA (activator) or L-aspartate (inhibitor). The non-linear progress curves are not abolished by preincubation of the enzyme with substrates, activator or inhibitor. Activation by acetyl-CoA is prevented and can be reversed by the addition of EDTA. Enzyme purified in the absence of EDTA is immediately responsive to activation by acetyl-CoA and inhibition by L-aspartate and shows linear progress curves. Incubation of such an enzyme with EDTA induces properties characteristic of the preparation purified in the presence of this chelating agent. Tight binding of EDTA to the enzyme could not be demonstrated