Partial Characterization of Protease Inhibitors of and Their Effect on Digestive Proteases of Marine Fish.

This piece of research evaluates the presence of protease inhibitors in the macroalga and provides an initial overview of their mode of action. The ability of protease inhibitors to inhibit digestive proteases of three marine fish species, as well as their capacity to hamper the hydrolysis of a reference protein by those fish proteases, were assessed. In addition, thermal stability and the mode of inhibition on trypsin and chymotrypsin were also studied. Dose-response inhibition curves and in vitro protein hydrolysis assays revealed a noticeable inhibition of fish enzymes when concentration increased in the assay. The thermal treatment of reduced markedly the inhibitory effect on fish digestive protease. Finally, Lineweaver-Burk plots indicated that trypsin and chymotrypsin inhibition consisted of a mixed-type inhibition mechanism in which the inhibitory effect depends on concentration. Overall, the results confirmed the presence of protease inhibitors in though heat treatment was enough for inactivating these compounds.