tripsina

Tripsina, known in English as trypsin, is a digestive enzyme and a member of the serine protease family, specifically the chymotrypsin superfamily. It cleaves peptide bonds on the carboxyl side of lysine and arginine residues in proteins, with reduced activity when followed by proline. In several Romance languages, including Italian and Spanish, the enzyme is called tripsina.

It is produced in the pancreas as an inactive zymogen, trypsinogen, by pancreatic acinar cells. In the duodenum, enteropeptidase (enterokinase) activates trypsinogen to trypsin, which then activates other pancreatic zymogens such as chymotrypsinogen and procarboxypeptidases, establishing a proteolytic cascade for protein digestion.

Trypsin uses a catalytic triad of histidine, aspartate, and serine residues (His57-Asp102-Ser195 in common numbering) to hydrolyze peptide bonds. Calcium ions help stabilize the enzyme, and the optimum pH is neutral to slightly alkaline, typically around 7 to 8, reflecting its intestinal environment. Its substrate scope is broad but shows preference for positively charged residues at the cleavage site.

Regulation occurs through endogenous inhibitors, notably SPINK1 (pancreatic secretory trypsin inhibitor) and related serpins. Premature activation of trypsin within the pancreas can lead to autodigestion and pancreatitis; hereditary pancreatitis has been linked to mutations in the trypsinogen gene (PRSS1) and SPINK1, highlighting the importance of tight control over trypsin activation.

In research and industry, trypsin is widely used to digest proteins for proteomics workflows and to dissociate cells in culture, making it an essential tool in biochemical and biomedical applications.