Abstract
The purified inorganic pyrophosphatase from the leaf of Amarantus blitum shows absolute magnesiumrequirement for its enzymeactivity. For maximumenzymeactivity, the Mg: PPi ratio was found to be 10:1 at the optimum pH of 9.0. This ratio varies with the shift of the pH. MgPPi2- was found to be the true substrate for the enzyme in the presence of the free Mg2+ ion. Some divalent metal ions and the fluoride anion severely inhibit the enzyme activity in the presence of Mg2+. The Michaelis constant (Km) and molecular weight of the enzyme were found to be 4.95 10-6 m and 32, 860, respectively. This enzyme is strictly specific for inorganic pyrophosphate.
