An improved procedure for the isolation of 3-phosphoglycerate kinase from yeast.

3-Phosphoglycerate kinase has been isolated from yeast by a new procedure. Over 1g was obtained from 450g of granulated baker's yeast; it had a specific activity of up to 940units/mg at 30 degrees C. Six distinct crystalline forms have been grown, at least one of these being suitable for X-ray diffraction studies. The crystalline preparation is pure, judged by starch-gel or sodium dodecyl sulphate-polyacrylamide-gel electrophoresis; the latter method indicating that the enzyme is monomeric, with a molecular weight near to 50000.