Further characterization of intestinal proteases was achieved with the use of specific
inhibitors in casein assays (Fig. 5). In intestine, PMSF caused the significantly highest
inhibition (77.1F1.8%), confirming the importance of serine proteases in this species. A
lower inhibition (29.8F6.8%) was obtained with EDTA. Incubation with specific trypsin
(TLCK) and chymotrypsin (TPCK) inhibitors showed higher percentage of inhibition
(71.5F3.5%) for trypsin as compared to chymotrypsin (57.7F2.8%). As for pancreas,
the presence of inhibitors caused 36.7–59.6% inhibition in overall proteolytic activities. In
comparison, Pepstatin, caused the highest significant reduction (96.1F1.6%) in stomach
extract, confirming the importance of pepsin-like activities in stomach.