Regulation of Pyruvate,Orthophosphate Dikinase From Maize Leaves.Magnesium-dependent Dimer-tetramer Interconversion
Pyruvate, orthophosphate dikinase(PPDK, EC 188.8.131.52.), a key enzyme in the C4 pathway of photosynthesis, catalyzes the formation of phosphoenolpyruvate(PEP) as follows: Pyruvate + MgATP + Pi = PEP + AMP + MgPPi The amount of magnesium ion required for the reaction appears to be much more than that required for the formation of MgATP and MgPPi complexes(1). The plant enzyme is a homotetramer and dissociates to inactive dimer or monomer in the absence of magnesium ion or under cold treatment(1).
KeywordsClosed Circle Elution Profile Incubation Mixture Quaternary Structure Basic Buffer
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