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Trypsin

Trypsin is a serine protease which catalyses a hydrolytic cleavage of peptides at the carboxyl group of the basic amino acids arginine and lysine. Trypsin is an important digestive enzyme, particularly in certain species where ancillary enzymes, such as pepsin and chymotrypsin are present in relatively small amounts, or are absent. Trypsin is present in the digestive tract of a wide variety of mammals. Its function is the hydrolytic cleavage of peptide bonds, thus reducing the size of large proteins and making them accessible to further degradation by other proteases. Trypsin is mainly used for the tryptic cleavage of peptides into small sections for sequencing, for detaching adherent cells from coated cell culture dishes and for cleaving fusion proteins into the target peptide and the fusion component, for activating propeptides (e.g. trypsinogen to trypsin) and for the recombinant production of peptide hormones. Trypsin is also used as a protein degrading enzyme in the processing of non-trypsin sensitive biopolymers. Because of its well known specificity, trypsin is also used as a selective protein cleavage tool in both analytical and preparative processes. Trypsin can be inactivated or inhibited by a number of specific or non-specific protease inhibitors, many of them belonging to the serpine family. Trypsin is used in biotechnological applications, especially in the cultivation of mammalian cells, where it serves as tool for the disintegration of large cell aggregates, or for the removal of cells from surfaces like microcarriers or cultivation trays. The most widely used in biotechnological applications is a trypsin inhibitor from soy beans. As most of these trypsin inhibitors are very specific, they are inactive against other contaminating proteases. Trypsin is also a component of some pharmaceutical preparations (ointments, dragees and aerosols for inhalation). Trypsin is typically prepared from the duodenal glands of various animal species and purified to different grades of purity. The purification of trypsin can be performed by a number of different biochemical processes, including precipitation, ion exchange chromatography and affinity chromatography.

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