Blog 2: Trypsin

Trypsin

Trypsin is a pancreatic serine protease, which is excreted by the pancreas and takes part in digesting foods, proteings, and other processes which occur within the body. The substrate specificity is based upon the positively charged lysine and arginine side chains. with substrate specificity based upon positively charged lysine and arginine side chains. Trypsin is a medium-sized round protein and is produced as an inactive proenzyme, trypsinogen. Trypsin is also comonnly used in food to improve workability of dough, ectract flavorings from vegetable or animal proteins, control aroma formation in dairy products, improve texture of fish, tenderize meat, and in the cold stabilization of beer.

Chemical Formula: C₆H₁₅O₁₂P₃

_{Molecular Weight: 372.1 g/mol}

_{CAS Number: 9002-07-7}

<sub>EC Number: 3.4.21.4

The figure below shows a serine amino acid that becomes activated by a histidine and an aspartate. These two assist in removing the hydrogen atom from the serine (white), making it more reactive. The pink inhibitor protein is bound in the active site, and the site of cleavage is noted by the green structure. There are also long lysine amino acids extending down to the lower right of the cleavage site. Here an interaction occurs between another aspartate within the enzyme. Trypsin then uses this interaction and cuts at locations near lysine or arginine amino acids.</sub>

_{The figure below shows a more in depth 2D model of Trypsin.}

 

The active site of Trypsin can be seen from the figure below. The active site contains three important amino acids, Histidine-57, Aspartate-102, and Serine-195. These active site residues are stabilized by a series of hydrogen bonds, and leaves them tethered together in a 3D spae. These three function together to break peptide bonds.

The figure below shows the overall catalyzed reaction of trypsin which involves reacting a polypetide with argenine and lysine segments with water to produce two seperate polypeptide fragments. Trypsin is also used to form polypeptides into amino acids, and proteins to peptides.

While the direct rate of reaction depends on concentration and other factors, from the figure below, you can see the vast increase in the rate of a catalyzed reaction vs uncatalyzed reaction for Trypsin.Optimal reaction rate occurs when the pH of Trypsin is between 7.5 and 8.5.

Sources:

• http://www.rcsb.org/pdb/101/motm.do?momID=46&evtc=Suggest&evta=Moleculeof%20the%20Month&evtl=OtherOptions
• http://en.wikipedia.org/wiki/Trypsin
• http://www.worthington-biochem.com/try/default.html
• http://www.bb.iastate.edu/~thorn/BBMB201/Trypsin_enzymatic_activity.html