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α-Chymotrypsinogen A from bovine pancreas

essentially salt-free, lyophilized powder

chymotrypsin A zymogen
CAS Number:
EC Number:
MDL number:

Quality Level

biological source

bovine pancreas


Type II


essentially salt-free, lyophilized powder

specific activity

≥40 units/mg solid

mol wt

25,656 Da by calculation

purified by

6× crystallization


1 mM HCl: soluble 10 mg/mL, clear, colorless

UniProt accession no.

foreign activity

α-chymotrypsin ≤1 U/mg (prior to activation by trypsin)

storage temp.


Gene Information

Related Categories

General description

Chymotrypsinogen from bovine pancreas is a zymogen containing 5 disulfide bridges. It has an isoelectric pH of 8.97.


α-Chymotrypsinogen A from bovine pancreas has been used as model protein crystallization reproducibility studies. It has also been used in the hydrolysis of α-gliadins prior to mass spectroscopy studies.
The enzyme from Sigma has been used in the non-invasive determination of solid-state protein conformation using near infrared (NIR) spectroscopy. It has been used to study the partitioning of protein in polymer/polymer aqueous two-phase systems. The enzyme has also been used for self-interaction chromatography applications, to test the rapid measurement of protein osmotic second virial coefficients. In this technique, the protein is immobilized on chromatographic particles and its retention is measured using isocratic elution.


1, 5 g in poly bottle
100, 250 mg in poly bottle

Biochem/physiol Actions

Chymotrypsinogen A requires limited proteolysis for its activation. Chymotrypsinogen A may be activated by trypsin and chymotrypsin (autolytic activation) to form m α, β, γ, δ and π chymotrypsin (depending upon the conditions of activation). Chymotrypsin is a protease that will preferentially cleave peptides on the carboxyl side of aromatic amino acids including tryptophan, tyrosine, and phenylalanine. It will also hydrolyze peptides on the carboxyl side of leucine, methionine, and alanine.
A serine protease that hydrolyzes peptide bonds with aromatic or large hydrophobic side chains (Tyr, Trp, Phe, Met) on the carboxyl end of the peptide bond.

Unit Definition

After activation to Chymotrypsin, one unit will hydrolyze 1.0 μmole of BTEE per min at pH 7.8 at 25 °C.

Other Notes

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

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Certificate of Origin

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Product Information Sheet


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