Trypsin

Trypsin (EC 3.4.21.4) is a serine protease from the PA clan superfamily, found in the digestive system of many vertebrates, where it hydrolyses proteins. Trypsin is formed in the small intestine when its proenzyme form, the trypsinogen produced by the pancreas, is activated. Trypsin cleaves peptide chains mainly at the carboxyl side of the amino acids lysine or arginine, except when either is followed by proline. It is used for numerous biotechnological processes. The process is commonly referred to as trypsin proteolysis or trypsinisation, and proteins that have been digested/treated with trypsin are said to have been trypsinized.

Function

In the duodenum, trypsin catalyzes the hydrolysis of peptide bonds, breaking down proteins into smaller peptides. The peptide products are then further hydrolyzed into amino acids via other proteases, rendering them available for absorption into the blood stream. Tryptic digestion is a necessary step in protein absorption as proteins are generally too large to be absorbed through the lining of the small intestine.

Trypsin 1

Trypsin-1, also known as cationic trypsinogen, is a protein that in humans is encoded by the PRSS1 gene. Trypsin-1 is the main isoform of trypsinogen secreted by pancreas, the others are trypsin-2 (anionic trypsinogen), and trypsin-3 (meso-trypsinogen).

Function

This gene encodes a trypsinogen, which is a member of the trypsin family of serine proteases. This enzyme is secreted by the pancreas and cleaved to its active form in the small intestine. It is active on peptide linkages involving the carboxyl group of lysine or arginine. Mutations in this gene are associated with hereditary pancreatitis. This gene and several other trypsinogen genes are localized to the T cell receptor beta locus on chromosome 7.

Clinical significance

Its malfunction acts in an autosomal dominant manner to cause pancreatitis. Many mutations that can lead to pancreatitis have been found. An example is a mutation at Arg 117. Arg 117 is a trypsin-sensitive site which can be cleaved by another trypsin and becomes inactivated. This site may be a fail-safe mechanism by which trypsin, when activated within the pancreas, may become inactivated. Mutation at this cleavage site would result in a loss of control and permit autodigestion, causing pancreatitis.

PRSS2

Protease, serine, 2 (trypsin 2) is a protein that in humans is encoded by the PRSS2 gene.

Function

This gene encodes a trypsinogen, which is a member of the trypsin family of serine proteases. This enzyme is secreted by the pancreas and cleaved to its active form in the small intestine. It is active on peptide linkages involving the carboxyl group of lysine or arginine. This gene and several other trypsinogen genes are localized to the T cell receptor beta locus on chromosome 7. [provided by RefSeq, Jul 2008].

References

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.