Cofactor interactions in the activation of tissue non-specific alkaline phosphatase: Synergistic effects of Zn2+ and Mg2+ ions

Abstract

The interactions of Mg2+ and Zn2+ ions in the activation of non-specific tissue alkaline phosphatase were investigated using crude extracts of rat kidney. Activation of alkaline phosphatase by the metal ions was accompanied by changes in the kinetic parameters of p nitrophenylphosphate hydrolysis. The results suggest some synergistic interactions between Mg2+ and Zn2+ ions in promoting the hydrolysis of p-nitrophenylphosphate by alkaline phosphatase. The results show that assays of alkaline phosphatase activity in homogenised tissue samples will give better responses if both Mg2+ and Zn2+ ions are included in the reactions.