Purification and Properties of a Polymetaphosphatase from Corynebacterium xerosis

Abstract

SUMMARY: An enzyme which splits high molecular weight polymetaphosphate (PMP) to orthophosphate has been extracted from Corynebacterium xerosis, partially purified and some of its properties studied. A method for the preparation of bacterial PMP labelled with 32P is described. The enzyme hydrolyses bacterial or synthetic PMP at the same rate. No formation of short-chain phosphate polymers was detected during the reaction and the enzyme did not attack metaphosphates smaller than hexametaphosphate. It does not transfer phosphate from PMP to ADP to form ATP, nor does it synthesize PMP from orthophosphate (Pi) in the presence of ATP or other nucleotides. All the metal ions tested, including Mg++, inhibited the enzyme. Sodium ethylenediaminetetraacetate (EDTA; 0·2 mm) stimulated the rate of reaction; higher concentrations inhibited. The significance of polymetaphosphate and enzymes which split it in micro-organisms is briefly discussed.