Kinetic analysis of cooperativity of phosphorylated L-type pyruvate kinase

Some Structural and Kinetic Aspects of L - Type Pyruvate Kinase Cooperativity

Kinetic analysis of the non-phosphorylated, in vitro phosphorylated, and phosphorylation-site-mutant (Asp8) forms of intact recombinant C4 phosphoenolpyruvate carboxylase from sorghum.

Steady-state kinetic analyses were performed on the non-phosphorylated, in vitro phosphorylated and phosphorylation-site mutant (Ser8-->Asp) forms of purified recombinant sorghum C4 phosphoenolpyruvate (P-pyruvate) carboxylase (EC 4.1.1.31) containing an intact N-terminus. Significant differences in certain kinetic parameters were observed between these three enzyme forms when activity was assa...

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...

Influence of phosphorylation on the interaction of effectors with rat liver pyruvate kinase.

The binding of the allosteric effector fructose 1,6bisphosphate to rat liver pyruvate kinase type L and the influence of phosphorylation on that binding has been investigated. Pyruvate kinase contains four binding sites for fructose 1,6-bisphosphate and the binding exhibits an overall positive cooperative behavior (nH = 2). Determination of the individual intrinsic binding constants showed the ...

Synthetic Phosphorylation of p38α Recapitulates Protein Kinase Activity

Through a "tag-and-modify" protein chemical modification strategy, we site-selectively phosphorylated the activation loop of protein kinase p38α. Phosphorylation at natural (180) and unnatural (172) sites created two pure phospho-forms. p38α bearing only a single phosphocysteine (pCys) as a mimic of pThr at 180 was sufficient to switch the kinase to an active state, capable of processing natura...