在脊椎动物中，作为消化酶而起作用。在胰脏是胰蛋白酶的前体胰蛋白酶原被合成后，作为胰液的成分而分泌，受肠激酶，或胰蛋白酶的限制分解成为活化胰蛋白酶，是肽链内切酶，它能把多肽链中赖氨酸和精氨酸残基中的羧基侧切断。它不仅起消化酶的作用，而且还能限制分解糜蛋白酶原、羧肽酶原、磷脂酶原等其它酶的前体，起活化作用。是特异性最强的蛋白酶，在决定蛋白质的氨基酸排列中，它成为不可缺少的工具。
In vertebrates, it acts as a digestive enzyme. It's synthesized in the pancreas as a precursor of trypsin, secreted as a component of pancreatic juice, restricted by enterokinase, or trypsin, and broken down into activated trypsin, which is an endopeptidase that cuts off the carboxyl side of lysine and arginine residues in the polypeptide chain. It not only plays the role of digestive enzymes, but also restricts the decomposition of other enzymes such as chymotrypsin, carboxypeptidase, phospholipase and other precursors, and plays an activation role. It is the most specific protease and becomes an indispensable tool in determining the amino acid arrangement of proteins.
