在脊椎動物中，作為消化酶而起作用。在胰臟是胰蛋白酶的前體胰蛋白酶原被合成后，作為胰液的成分而分泌，受腸激酶，或胰蛋白酶的限制分解成為活化胰蛋白酶，是肽鏈內切酶，它能把多肽鏈中賴氨酸和精氨酸殘基中的羧基側切斷。它不僅起消化酶的作用，而且還能限制分解糜蛋白酶原、羧肽酶原、磷脂酶原等其它酶的前體，起活化作用。是特異性最強的蛋白酶，在決定蛋白質的氨基酸排列中，它成為不可缺少的工具。
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.
