Trypsin

TRYPSIN

Biological Source

Trypsin is a proteolytic enzyme produced by Ox pancreas, Bos taurus, belonging to family Bovidae.

It is one of the three principal digestive proteinases which along with other proteinases like pepsin and chymotrypsin break the dietary protein molecules to their amino acids and peptide component. Trypsin cleaves proteins at the carboxyl side like ‘C-terminals’ of the basic amino acids lysine and arginine. Trypsin is an endopeptidase which cleavage occurs within the polypeptide chain and not the terminal amino acids located at the ends of polypeptides. The aspartate residue located in trypsin is responsible for attracting and stabilizing positively charged lysine and/or arginine.

Production

Trypsin is produced by pancreas in the form of trypsinogen. Trypsin is then transported to the small intestine, where the proteins are cleaved into polypeptides and amino acids. As trypsin is an autocatalytic enzyme, it by itself catalyses the conversion of trypsinogen to trypsin. Another enzyme (enterokinase) is also required in small amount to catalyse the initial reaction of trypsinogen to trypsin.

Process of digestion by trypsin gets started in stomach and is continued to the small intestine where the environment is slightly alkaline. Trypsin has maximum enzymatic activity at pH 8.

Chemical Composition

It has a similar structure as that of other pancreatic proteinase like chymotrypsin and also has the similar mechanisms of action. They differ only in their specificity. Trypsin is active against peptide bonds in protein molecules that have carboxyl groups donated by amino acids like the arginine and lysine, whereas chymotrypsin are active against the carboxyl group denoted by tyrosine, phenylalanine, tryptophan, methionine, and leucine. Trypsin is considered the exceptional of all other proteolytic enzyme due to its attack on restricted number of chemical bonds. Trypsin is widely employed as a reagent for the orderly and unambiguous cleavage of proteins in which amino-acid sequence is to be determined.

Uses

In a tissue culture lab, trypsin is used to resuspend cells adherent to the petri dish wall during the process of harvesting cells. It is also used to harvest corn and oats. Trypsin is vital in a cow’s diet, without it they would not be able to digest the grass they eat.