[Effect of the redox state of glutathione on acetate kinase activity in E. coli].

Oxidized glutathione inhibits acetate kinase (EC 2.7.2.1) of E. coli. The rate of inactivation depends on ATP concentration. The rate constant for the glutathione-induced inhibition is 0.17 min-1, Ki is 4.2 mM (pH 7.2, 25 degrees C). The inhibition of acetate kinase by glutathione is reversible, the equilibrium constant being equal to 4.4 or 0.09 at saturating concentrations of ATP (pH 8.0, 25 degrees C). The physiological level of reduced and oxidized glutathione can modulate the acetate kinase activity in vivo.