PROTEIN-HYDROLYZING ENZYMES IN THE DIGESTIVE SYSTEMS OF THE ADULT MEXICAN BLUE ABALONE, HALIOTIS FULGENS (GASTROPODA)

The physiology of protein digestion by adult abalone was investigated. The female and male digestive systems of blue abalone were studied by using enzymatic techniques, including proteinaceous-substrate hydroly sis, specific synthetic-substrate hydrolysis, specific inhibitors in p roteinaceous-substrate hydrolysis, and proteinase composition by subst rate SDS-PAGE. The highest proteolytic activity was found in the intes tinal and rectal fluids at alkaline pH, followed by hepatopancreas and crop-stomach content at acid pH. Trypsin and chymotrypsin activity we re found along the intestine and rectum. Chymotrypsin activity was 10 times higher than trypsin activity. Several unknown proteinase activit ies were found in the hepatopancreas, crop-stomach content, intestinal fluid, and rectal fluid. (C) 1997 Elsevier Science B.V.