Partial characterization of digestive proteases in Pacific red snapper Lutjanus peru Nichols & Murphy, 1922 (Perciformes: Lutjanidae)

Pacific red snapper (Lutjanus peru) is an important commercial species in Mexico with great aquaculture potential; however, digestive physiology still unknown. Therefore, the objective of present work was to characterize proteases L. peru juvenile using biochemical and electrophoretic techniques. Results showed a higher acid protease activity than alkaline proteases, trypsin, chymotrypsin, leucine aminopeptidase (LAP). The optimum temperature for between 30 40°C. Trypsin two maximum peaks (30 50°C), while LAP had temperatures 50, 50 60, 40°C, respectively. Moreover, pH 2 3. Also, chymotrypsin optimums at 6, 9, 5, respectively, although values 6 9. Acid zymogram three isoforms, totally inhibited by pepstatin A. Alkaline revealed six bands (125.4, 67.2, 57.9, 48.6, 29.8, 26.9 kDa), which were specific serine-proteases metalloproteases inhibitors. In conclusion, main digestion depends on stomach are characteristic carnivorous fish, followed intestinal supported mainly chymotrypsin.