The phosphatase and metaphosphatase activities of pea extracts

Abstract

Pea extracts have a hexametaphosphatase activity which is closely associated with an un-specific phosphatase. A variety of procedures, including protein precipitations, heat denaturation, adsorption and ion-exchange chromatog-raphy do not separate these activities or appreciably alter their ratio. The phosphatase liberates orthophosphate from tripolyphosphate, trimetaphosphate, [beta]-glycerophosphate, and adenosine di- and tri-phosphate, but not from tetrametaphosphate. It does not liberate phenol from diphenyl phosphate. The phosphatase is inhibited by fluoride and molybdate but not by a variety of compounds that combine with -SH groups. Ion-exchange chromatography of the phosphatase, with a buffer of higher pH as eluting agent, reveals 2 distinct enzymically active components. Each can be separated from the other and rechromato-graphed as a single peak. The 2 components are very similar in properties. They have the same pH optimum, are not affected by Mg2+ ions or chelating agents, have similar heat stabilities and differ only quantitatively in their specificities.