title: Comparison of calpain I and calpain II from carp muscle.
abstract: 1. The content of calpain II is 3.4 times more than that of calpain I when estimated by the elution profiles from a column of DEAE-cellulose. 2. Calpain I required 1 mM Ca2+ and calpain II required 5 mM Ca2+ to show the full activities. These data demonstrated that Ca2+-sensitivities of both calpains were lower than those of mammalian calpains, respectively. 3. The optimum caseinolytic activity was pH 7.2 for calpain I and pH 7.5 for calpain II. 4. The molecular weight of calpain I was estimated to be 110 k and that of calpain II to be 120 k by gel filtration. 5. Calpain I was much more heat-stable than calpain II around 50-60 degrees C. 6. Both calpains were sensitive to calpastatin, an endogenous inhibitor for calpain.
authors.affiliation: Department of Fisheries, Faculty of Agriculture, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Toyohara
authors.forename: Y
authors.initials: Y
authors.lastname: Makinodan
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002154:Calpain / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002347:Carps / Q000378:metabolism*; D003530:Cyprinidae / Q000378:metabolism*; D006358:Hot Temperature; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*
chemical_list: D002154:Calpain; D002118:Calcium