PURIFICATION AND SOME PROPERTIES OF A CARBOXYPEPTIDASE-B FROM DOGFISHSCYLIORHINUS-CANICULA

A carboxypeptidase B (CPB) has been purified from dogfish (Scyliovhinu s canicula) pancreas and partially characterized, The purification pro cedure included acetone precipitation, ion-exchange chromatography on a CM-cellulose column and gel filtration on Sephadex G-75, The purifie d enzyme migrates as a single band both on PAGE and SDS-PAGE, Its mole cular mass is estimated to be about 32 kDa. The optimum of activity is obtained at pH 7.5-8.2. The enzyme is inhibited by typical metal-chel ating agents (EDTA and o-phenanthroline) and by Hg2+, It is activated by Co2+, L-cysteine and by heat treatment at 40 degrees and 50 degrees C, Kinetic parameters, K-m and k(cat), of native enzyme, Co2+-activat ed CPB and heat-treated CPB have been determined.