Purification and characterization of a calcium-dependent protease from rat liver

Abstract

A Ca-dependent protease, previously identified in rat liver and designated peak II, was purified and characterized. The Ca-dependent proteolytic activity was accounted for by an 80,000-dalton protein. Depending on the method of purification, this protease could be associated with a 28,000-dalton subunit, which was devoid of protease activity. The catalytic characteristics of the 2 different forms of the protease were indistinguishable. Each was half-maximally activated by .apprx. 250 .mu.M Ca.