title: Assaying for pyruvate, orthophosphate dikinase activity: Necessary precautions with phosphoenolpyruvate carboxylase as coupling enzyme.
abstract: Phosphoenolpyruvate carboxylase (EC 4.1.1.31), used as a coupling enzyme in the assay of the pyruvate, orthophosphate dikinase (EC 2.7.9.1) forward reaction, is a serious limiting factor for the overall rate when added at a level of 0.2-0.3 unit/ml of assay medium. Nonlimiting assay conditions are obtained by either increasing the level of the coupling enzyme to 3 units/ml or adding 6mM glucose-6-phosphate as an activator/stabilizer of phosphoenolpyruvate carboxylase.
authors.affiliation: Laboratory of Plant Physiology, Department of Biology, University of Patras, Patras, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Salahas
authors.forename: Y
authors.initials: Y
authors.lastname: Manetas
authors.forename: N A
authors.initials: NA
authors.lastname: Gavalas