Chymotrypsin A (alpha), Bovine Pancreas, TLCK Treated (EC 3.4.21.1, Bovine Pancreas)

Chymotrypsin preferentially catalyzes the hydrolysis of peptide bonds involving L-isomers of tyrosine, phenylalanine and tryptophan. It also readily acts upon amides and esters of susceptible amino acids. Chymotrypsin catalyzes the hydrolysis of bonds of leucyl, methionyl, asparaginyl and glutamyl residues. Chymotrypsinogen A is extracted from pancreatic tissue as a zymogen. Pancreatic extract contains approximately equal amounts of two forms of the zymogen, chymotrypsin A and chymotrypsin B. Chymotrypsin A may be activated to alpha, pi, beta, or gamma chymotrypsin. The enzyme is inhibited by heavy metals, the natural trypsin inhibitors to various degrees, an inhibitor from potato, and organophosphorous compounds. Purity: 3X crystallized and treated with 1-chloro-3-tosylamido-7-amino-2-heptanone (TLCK) to inhibit trypsin activity [Shaw, et al., Biochemistry, 4, 2219 (1965)]. Dialyzed against 1mM HCl to remove autolysis products and low molecular weight contaminants. Activity: >45 units/mg protein, Trypsin: <0.1%, A280/mg dw: As reported, % Protein: As reported, Unit Definition: 1 unit hydrolyzes 1umole of benzoyl-L-tyrosine ethyl ester (BTEE) per minute at 25ºC, pH 7.8. An activity of 45 units per mg using the above definition, is the equivalent of 10,000 optical density or 1330 N.F. units per mg using ATEE as a substrate. 1 BTEE unit = 29.5 USP/NF units. Quality Control: SDS-PAGE, Storage and Stability: The enzyme is stable for days in solution at pH 3.0. For long term storage as a powder, store at 4ºC. Protect from moisture.