Effect of Metal Ions on Brain Peptidase Activity. ∗

Abstract

Summary

The effect of Ca⁺⁺, Mg⁺⁺, Cu⁺⁺, Zn⁺⁺, Cd⁺⁺, Co⁺⁺, Mn⁺⁺, MoO₄, Ni⁺⁺, Fe⁺⁺⁺ and Al⁺⁺⁺ was studied on the enzymatic hydrolysis, by cerebral peptidases, of glycyl-L-leucine and glycyl-diglycine. The inhibition was shown to be of different orders of magnitude for different metals. Only cobalt ions were shown to enhance the hydrolysis of glycyl-diglycine by promoting the hydrolysis of the diglycine residue in the tripeptide which normally resists hydrolysis. This effect was specific for diglycine and not applicable to the other N-glycyl dipeptides which are normally not hydrolyzed by brain.