[Evidence and properties of digestive proteases in young mugilidae during the first year of life]

Abstract

Proteolytic activity was observed in extracts from the digestive tract of Mugil auratus and Mugil capito; its maximum occurs at about pH 2 and 9. Activity in the acid range is mainly found in stomach extracts and the enzyme may be considered as similar to pepsin and cathepsins. In the alkaline range, the main activity is recorded in the region of the pyloric caeca. Activities of the trypsin, chymotrypsin, A and B carboxypeptidases and elastase type are found. The effects of pH and temperature on some activities are studied: optimal pH are about 2.6 and 3,4 with pepsin-like activity, between 8,1 and 8,5 with trypsin-like activity and between 7,8 and 8,5 with chymotrypsin-like activity; incubation optimal temperature (pH 2,2) is found between 35 degrees and 40 degrees.