Teh pH-dependence of the inhibitory effects of several divalent cations on the ovine intestine adenosine deaminase activity

Abstract

1. 1. In the reaction performed in an alkaline region, the inhibitory effects of Ba 2+, Ca 2+, Mg 2+, Mn 2+ and Sr 2+ on the bovine intestine adenosine deaminase were observed. 2. 2. Mn 2+ completely inhibited its activity at pH 8.0, and Ca 2+ and Mg 2+ at pH 9.0. The inhibition of the latter two metals was reversible, and low hydrogen ion concentration was required when binding. The addition of EDTA reduced the inhibitory effects but a difference was found between Ca 2+ and Mg 2+ in the recovery process.