Kallikrein Inhibitory Capacity of α 2 -Macroglobulin Subunits

Abstract

Summary

Human α₂-macroglobulin can be dissociated by dialysis against 3 M urea into two 11S subunits which remain stable under physiologic conditions. These subunits retain kallikrein inhibitory capacity albeit at a reduced level when compared with the native protein. They furthermore protect bound kallikrein from further inhibition by native α₂-macroglobulin. Bound kallikrein can not be dissociated from either the subunits or the native protein by Sephadex G-200 gel filtration.