Purification and properties of carp (Cyprinus carpio) muscle calpain II (high-Ca2+-requiring form of calpain).

Calpain (Ca2+-dependent cysteine proteinase) was purified to apparent homogeneity from carp muscle by the method of DEAE-cellulose, hydroxylapatite and Ultrogel AcA 34 column chromatographies. The purified enzyme is classified as calpain II (high-Ca2+-requiring form of calpain) from the effects of Ca2+ concentration, pH and the antibiotics on the activity. Carp muscle calpain II was inhibited by rat liver calpastatin, the specific inhibitor for calpain. It is probable that the calpain-calpastatin system may play a biologically fundamental and common role in various cells, since the inhibitory effect of calpastatin on calpain from different tissues of different species is well conserved.