Trypsin inhibitor

Trypsin inhibitors are chemicals that reduce the availability of trypsin, an enzyme essential to nutrition of many animals, including humans.

There are four commercial sources of trypsin inhibitors.

Source	Molecular weight	Inhibitatory power	Details
Serum (α1-antitrypsin)	52 kDa		Also known as serum trypsin inhibitor
Lima beans	8-10 kDa	2.2 times weight	There are six different lima bean inhibitors.
Bovine pancreas	6.5 kDa	2.5 times weight	Kunitz inhibitor, or BPTI (basic pancreatic trypsin inhibitor, is the best known pancreatic inhibitor. Chymotrypsin is also inhibited by this chemical, but less tightly. When extracted from lung tissue, this is known as aprotinin.
Ovomucoid	8-10 kDa	1.2 times weight	Ovomucoids are the glycoprotein protease inhibitors found in raw avian egg white. There are other protease inhibitors in ovomucoids as well.
Soybeans	20.7-22.3 kDa	1.2 times weight	Soybeans contain several inhibitors; the one in the chart is considered the primary one. All of them bind chymotrypsin to a lesser degree.

Eggs of Pomacea canaliculata, scale bar in cm.

A study revealing that proteinase inhibitor from the eggs of the freshwater snail Pomacea canaliculata, interacts as a trypsin inhibitor with the protease of potential predators, was reported in 2010, the first direct evidence for this mechanism in the animal kingdom.

See also

• Serine protease inhibitor
• Protease inhibitor

References

• Jones et al., Biochem., 2, 66, (1963)
• Lineweaver and Murray JBC, 171, 565 (1947)
• Kunitz and Northrop J. Gen. Physiol., 19, 991 (1936)
• Fraenkel-Conrat, et al., Arch. Biochem. Biophys., 37, 393 (1952)
• Frattali, V., and Steiner, R.: Biochem., 7, 521 (1968)

External links

• MeSH Trypsin+inhibitors