Pyruvate Kinase from Yeast

Abstract

Publisher Summary This chapter discusses about yeast pyruvate kinase (PK), which was first purified from bakers' yeast by Washio et al. in 1959 and obtained in pure form from brewers' yeast by Hess et al. and Hunsley and Suelter. Yeast PK is applied in biochemistry. The optimum pH depends on the phosphoenolpyruvate concentration. A characteristic of yeast PK is the considerable activation by F-1,6-P2, so that in many cases it is of interest to determine both the activity and the activation factor in extracts or during purification procedures. The conditions described for the optimum assay can also be used to measure the relationship between the rate of the reaction and the substrate concentration. Because yeast PK shows a sigmoidal saturation curve and substrate inhibition at high concentrations, extrapolation by the methods described in the literature results in inaccurate constants. The accuracy of the measurements with a recording spectrophotometer is at least ± 3%.