Abstract: | Labile polyphosphate phosphohydrolase from Endomyces magnusii is 27-fold purified by means of fractionation with ammonium sulphate, gel filtration on Sephadex G-75 and Biogel P-60 and chromatography on DEAE cellulose. Chromatography on DEAE Sephadex A-50, isoelelctric focusing and polyacrylamide gel electrophoresis of the enzyme preparation revealed 3 different fractions with polyphosphate phosphohydrolase activity (PPPH1, PPPH2 and PPPH3). Relative content of these fractions in E. magnusii cells is 30%, 55% and 15% respectively. Isoelectric points are: PPPH1--pH 5.1--5.2; PPPH2--pH 6.0--6.1; PPPH3--pH 6.3--6.4. PPPH1 and PPPH2 are found to be the most labile. PPPH3 is more stable under isolation procedure and storage. The fractions have similar molecular weight (48 000 +/- 3000). |