Characterization and functional properties of digestive proteases in two sparids; gilthead seabream (Sparus aurata) and common dentex (Dentex dentex)

Digestive proteases present in two sparids, seabream (Sparus aurata) and co mmon dentex (Dentex dentex), have been characterized using both biochemical and electrophoretic techniques. Although optimum pH and temperature for ma ximum activity of both acid and alkaline proteases were similar in the two species, important differences in total activity, as well as in thermal and pH stability were found. Specific inhibitors and SDS-PAGE zymograms were u sed to clarify such differences. Evidences support the existence of a more active and complex protease set in dentex. Results are discussed from the p erspective of their application to the formulation of feeds for each specie s.