Über Hefephosphatase. (1. Mitteilung über die Enzyme der Gärung.)

Abstract

I. Yeast phosphatase is prepared free from other enzymes by glycerol extraction of dried yeast, dialysis oi the extract, and subsequent adsorption of impurities on Al(OH)3-C[gamma]. The enzyme is most active at pH 6-7. It is specific for [alpha]-glycerophosphate, unlike liver and kidney phosphatase, which attack both [alpha]- and [beta]-glycerophosphates. Yeast phosphatase attacks the hexose phosphates and phosphoglyceric acid much more slowly than [alpha]-glycerophosphate.[long dash]II. Yeast phosphatase phosphorylates glucose only when an oxido-reduction enzyme (orange seed redoxase or Warburg''s "Zwischenferment"), cozymase, Mg ions, hexose di-phosphate, and acetaldehyde are present. But yeast phosphatase loses this phosphatase activity when it is freed from zymohexase. In fact, a phosphatase-free zymohexase preparation can be substituted for yeast phosphatase in the phosphorylation mixture. The zymohexase itself may be omitted if the product of its action on hexose diphosphate, namely dihydroxyacetone phosphoric acid, is substituted for hexose diphosphate in the reaction mixture. The necessary and sufficient components of the yeast phosphatase system are therefore glucose, inorganic phosphorus, dihydroxyacetone phosphoric acid, acetaldehyde, cozymase, Mg ions, and "Zwischenferment," which latter is probably a complex.