C7762

α-Chymotrypsin from bovine pancreas

Type I-S, essentially salt-free, lyophilized powder

• Synonym(s): α-chymotrypsin A and B, alpha-chymotrypsin
• CAS Number: 9004-07-3
• Enzyme Commission number: 3.4.21.1 (BRENDA, IUBMB)
• EC Number: 232-671-2
• MDL number: MFCD00130481
• UNSPSC Code: 12352204
• eCl@ss: 42010112
• NACRES: NA.54

Properties

• type: Type I-S
• form: essentially salt-free, lyophilized powder
• specific activity: ≥40 units/mg protein
• mol wt: 25 kDa
• purified by: 3× crystallization
• solubility: 1 mM HCl: soluble 2.0 mg/mL, clear
• UniProt accession no.: P00767
• storage temp.: −20°C
• Gene Information: cow ... CTRB1(618826)

Description

Application

α-Chymotrypsin from bovine pancreas has been used in a study to investigate protein extraction by Winsor-III microemulsion systems. α-Chymotrypsin from bovine pancreas has also been used in a study to investigate a new specific fullerene-based fluorescent probe for trypsin.

The product has been used to investigate the inhibitory effect of several ether oligomers against the enzyme. It has also been used to cleave pro-phenoloxidase in order to estimate total phenoloxidase in haemolymph. Furthermore, the enzyme has been used as a positive control in chymotrypsin assays using salivary gland and anterior midgut extracts of Deraeocoris nigritulus.

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, as well as 10 mM of 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.

Unit Definition

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

Preparation Note

Prepared free of autolysis products and low molecular weight contaminants.

The powder may be reconstituted in 1 mM HCl at 2 mg/mL concentration to form a clear solution.

Analysis Note

Minimum 85% protein

Protein determined by E1%/280

Other Notes

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

Safety Information

• Pictograms: GHS08,GHS07,GHS09
• Signal Word: Danger
• Hazard Statements: H302,H315,H319,H334,H335,H400
• Precautionary Statements: P261 - P264 - P273 - P301 + P312 - P302 + P352 - P305 + P351 + P338
• Hazard Classifications: Acute Tox. 4 Oral - Aquatic Acute 1 - Eye Irrit. 2 - Resp. Sens. 1 - Skin Irrit. 2 - STOT SE 3
• Target Organs: Respiratory system
• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 1
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves