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Updated: Aug 1, 2026

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions
Published on: April 19, 2013
The regulatory properties of yeast pyruvate kinase. Effect of pH
Abstract:
The kinetics of pyruvate kinase from Saccharomyces cerevisiae were studied at 25 degrees C as a function of the concentrations of the substrates ADP, phosphoenolpyruvate and Mg2+ and the effector H+ in the pH range 5-6.6. The enzyme was activated by 100 mM-K+ and 32 mM-NH4+ throughout. It was found that the data could be described by the exponential model for a regulatory enzyme. On that basis, it was concluded that the binding of H+ is positively interactive and that the protonated enzyme is catalytically inactive. It was also found that H+ interacts positively with phosphoenolpyruvate but negatively with both ADP and Mg2+.
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