Analysis Note

Protein determined by E1%/280

Application

The enzyme from Sigma has been used to study the structure-function relationship in glycosylated α-chymotrypsin using immobilized metal-ion affinity chromatography (IMAC) and immobilized metal-ion affinity capillary electrophoresis (IMACE).

Biochem/physiol Actions

α-Chymotrypsin is a serine peptidase and has 241 amino acid residues contained in three polypeptide chains (A chain-13 residues, B chain-131 residues, and C chain-97 residues) linked by disulfide bridges. Molecular weight of this enzyme is found to be 25 kDa. The pI is 8.75. It selectively hydrolyzes peptide bonds on the C-terminal side of tyrosine, phenylalanine, tryptophan, and leucine. Ca²⁺ activates and stabilizes the enzyme. The enzyme is inhibited by diisopropyl fluorophosphate (DFP), phenylmethanesulfonyl fluoride (PMSF), N-p-tosyl-L-phenylalanine chloromethyl ketone (TPCK), chymostatin, aprotinin, α1-antitrypsin, and α2-macroglobulin, 10 mM Cu²⁺ and Hg²⁺.

A serine protease that hydrolyzes peptide bonds with aromatic or large hydrophobic side chains (Tyr, Trp, Phe, Met, Leu) on the carboxyl end of the bond.

Other Notes

View more information on chymotrypsin at www.sigma-aldrich.com/enzymeexplorer

Packaging

250, 500 mg in poly bottle

1, 10 g in poly bottle

Preparation Note

Produced from 3× crystallized chymotrypsinogen

Unit Definition

One unit will hydrolyze 1.0 µmole of BTEE per min at pH 7.8 at 25 °C.