ADENYLATE PYROPHOSPHORYLASE - PURIFICATION, REACTION SEQUENCE, AND INHIBITION BY SODIUM ION

Adenylate pyrophosphorylase (EC 2.4.2.7) was partially purified from extracts of B. subtilis to a form suitable for kinetic studies. Its molecular weight was approximately 45,000 by Sephadex chromatography. From the kinetics of product inhibition, and the requirement for PPi for reversal of the reaction, it was concluded that the synthesis of nucleotide proceeds as an ordered sequential reaction. The enzyme is inhibited specifically by sodium ion and this inhibition is antagonized by magnesium. The possible mechanism is analyzed and discussed. © 1969.