Phosphorylation in living yeast

recently described the preparation from yeast of a cell-free enzyme, "heterophosphatese" which catalyses the transference of phosphate from (muscle) adenosinetriphosphate to glucose or fructose with the formation of a hexosephosphate. Later Meyerhof [1935] showed that prepara- tions of hexokinase contain "heterophosphatese". The natural inference from these experiments is that adenosinetriphosphate may act as a phosphate carrier in alcoholic fermentations by living yeast, in a manner analogous to its role in muscle glycolysis [see Meyerhof & Kiessling, 1935]. This receives material support by the isolation of the triphosphate in crystalline form from the trichloroacetic acid extract of fresh yeast by Wagner-Jauregg [1936] who con- cluded that it was identical with that of muscle. The amount obtained (60 mg. from 100 g. yeast) contains approximately 2 % of the total phosphorus of the yeast.