3.4.22.53	50% inactivation by autolysis after 1 min at 30°C, pH 7.5, 10 mM Ca2+	
3.4.22.53	50% inhibition by trypsin after 3 min at 30°C, pH 7.5	
3.4.22.53	bovine fetuin A stabilizes proteolytic activity of purified m-calpain incubated in the presence of mM calcium chloride and prevents calcium-dependent m-calpain aggregation	
3.4.22.53	m-calpain loses 50-55% of its proteolytic activity within 5 min during incubation at pH 7.5 in 300 mM or high salt and at a slower rat in 100 mM salt. This loss of activity is not reversed by dialysis for 18 h against a low-ionic-strength buffer at pH 7.5. Proteolytic activity of the unautolyzed calpains is not affected by incubation for 45 min at ionic strength up to 1000 mM. Ionic strengths of 100 mM or above cause dissociation of the two subunits of autolyzed calpains. The dissociated large subunits aggregate to form dimers and trimers, which are proteolytically inactive