Characterization of digestive proteases in the Senegal sole Solea senegalensis Kaup, 1858 | Caracterización de las proteasas digestivas del lenguado senegalés Solea senegalensis Kaup, 1858

Spanish; Castilian. Se caracterizan las proteasas digestivas de Solea senegalensis Kaup, 1858. El óptimo de actividad para el extracto estomacal se situó en valores de pH entre 2,0 y 2,5 y para los intestinales entre pH:9,5 y pH:10,0. El extracto de estómago se mostró muy estable a distintos valores de pH, excepto a pH:12,0. Los extractos intestinales mostraron ser inestables a pH ácido. Los óptimos de temperatura se localizaron entre 37 y 40 grados C. Las proteasas fueron termolábiles por encima de 50 grados C. El uso de sustratos e inhibidores específicos evidenció la presencia mayoritaria de pepsina en el estómago y de serina proteasas de tipo tripsina y quimotripsina en el intestino. Los zimogramas confirmaron la existencia de una sola proteasa en el extracto de estómago y de siete fracciones activas en el intestino.

English. The digestive proteases of Senegal sole Solea senegalensis Kaup, 1858 were studied. Acid proteases showed their peak of activity between pH:2.0 and pH:2.5. Optimum activity for intestinal proteases was found in the range of pH:9.5-10.0. The results of acid protease stability under different pH indicated that only pH 12.0 affect these enzymes. Alkaline proteases were highly sensitive to acidic pH. Temperature optimums were found at 37-40 deg C. Thermal stability analysis showed that proteases kept up their activities until 50 deg C. The use of specific proteases inhibitors showed the presence of aspartic proteases in stomach and serine proteases (trypsin and chymotrypsin-like) in the intestine. Zymograms confirm the existence of a single protease in stomach extract, and seven active fractions in the intestine extracts.