Trypsin

Trypsin is an enzyme that can cleave proteins at specific positions. It cuts at R-X and K-X bonds, unless X is P (see amino acids for the codes). Main trypsin preparations contain some chymotrypsin activity. The pH? optimum for trypson to work is pH7 - pH9, and it is permanently inactivated at ph>11. Trypsin retains activity in 0.1% SDS?, 1 M guanidine? HCl? and 30% ethanol. The [autocatalytic activity]? of trypsin can be slowed down with 20 mM calcium.

Together with pepsin? and chymotrypsin, Trypsin is one of the three principal digestive proteinases. It is found in the stomach, where it degrades proteins to polypeptides and amino acids.