INORGANIC PYROPHOSPHATASE OF DESULFOVIBRIO DESULFURICANS

Abstract

Akagi , J. M. (University of Illinois, Urbana) and L. Leon Campbell . Inorganic pyrophosphatase of Desulfovibrio desulfuricans . J. Bacteriol. 86: 563–568. 1963.—The inorganic pyrophosphatase of Desulfovibrio desulfuricans was purified 136-fold by (NH 4 ) 2 SO 4 and ethanol fractionation and diethylaminoethyl cellulose chromatography. Mg ++ or Mn ++ was required for optimal activity; Co ++ was only 65% as effective as Mg ++ . The optimal ratio of Mg ++ to pyrophosphate was 1.0 at pH 8.0. The K s for the pyrophosphatase was found to be in the region of 1.9 × 10 −3 m . Sulfhydryl inhibitors and sodium fluoride had no effect on enzyme activity at a concentration of 10 −3 m . The purified enzyme did not hydrolyze adenosine triphosphate, glycerol phosphate, diphenyl phosphate, or p -nitrophenyl phosphate. Thermal stability studies showed that the enzyme is rapidly inactivated at temperatures above 40 C.