All Photos(5)



α-Chymotrypsin from bovine pancreas

Type II, lyophilized powder, ≥40 units/mg protein

alpha-chymotrypsin, α-chymotrypsin A and B
CAS Number:
Enzyme Commission number:
EC Number:
MDL number:

Quality Level


Type II


lyophilized powder

specific activity

≥40 units/mg protein

mol wt

25 kDa


protein, ≥85%


white to off-white

UniProt accession no.


diagnostic assay manufacturing

storage temp.


Gene Information

Looking for similar products? Visit Product Comparison Guide

Related Categories


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).


250, 500 mg in poly bottle
1, 10 g in poly bottle

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.

Unit Definition

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

Preparation Note

Produced from 3× crystallized chymotrypsinogen

Analysis Note

Protein determined by E1%/280

Other Notes

Signal Word


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



Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Origin

Enter Lot Number to search for Certificate of Origin (COO).

Technical Information

More Documents

Quotes and Ordering

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. What is the molecular weight of alpha-chymotrypsin from bovine pancreas, product C4129?

    The molecular weight of alpha chymotrypsin, reported in the literature, is approximately 25 kDa.

  6. How do you recommend preparing a solution of Product No. C4129?

    It is recommended to reconstitute Product No. C4129 in 1 mM hydrochloric acid containing 2 mM calcium chloride. The calcium functions as a stabilizer, and possibly an activator, of the enzyme.

  7. How can solutions of alpha chymotrypsin (Product No. C4129) be stored?

    Stock solutions prepared in 1 mM HCl, containing 2 mM calcium chloride, can be stored at -20 ° for about one week.

  8. What is the pH optimum for the enzyme, Product No. C4129?

    The pH optimum for alpha-chymotrypsin is between pH 7.5-8.5. Please see the following reference: Wilcox, P.E., Chymotrypsingogens-chymotrypsins, Methods in Enzymology, 19, 64-80 (1970).

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Antonio Jesús Vizcaíno et al.
Marine drugs, 18(6) (2020-06-24)
This piece of research evaluates the presence of protease inhibitors in the macroalga Ulva ohnoi and provides an initial overview of their mode of action. The ability of Ulva protease inhibitors to inhibit digestive proteases of three marine fish species
Ines Atuh Ngoh et al.
Experimental parasitology, 218, 107969-107969 (2020-08-29)
Invasion of human red blood cells (RBCs) by Plasmodium parasites is a crucial yet poorly characterised phenotype. Two-color flow cytometry (2cFCM) promises to be a very sensitive and high throughput method for phenotyping parasite invasion. However, current protocols require high
K Y Jiang et al.
Biochimica et biophysica acta, 1433(1-2), 198-209 (1999-08-14)
Chemical glycosylation of bovine alpha-chymotrypsin, by a glucosamine adduct on the carboxyl group, results in the modification of its catalytic activity. The structural alterations of alpha-chymotrypsin resulting from its glycosylation are studied by immobilized metal-ion affinity chromatography (IMAC) and immobilized
Shannon Gwala et al.
Food & function, 11(3), 2509-2521 (2020-03-07)
Postharvest storage of legumes is a strategy to ensure food security. However, the hard-to-cook phenomenon, partly explained by pectin-cation-phytate theory, may develop during storage. Based on this theory, minerals could be redistributed within the matrix, affecting the concentration of free/bound
Olivia Ogilvie et al.
MethodsX, 7, 101076-101076 (2020-10-10)
Mass spectrometry (MS) is an emerging method to determine the accurate concentration of immunogenic gluten peptides. It is of interest to quantify specific peptides within the gluten peptidome due to the role they play in the activation of the celiac


Procedure for Enzymatic Assay of α-Chymotrypsin (EC

Follow our procedure for the determination of a chymotrypsin activity. This enzymatic assay of alpha chymotrypsin guides you through the entire process and necessary calculations.

Related Content


Analytical Enzyme Chymotrypsin: Chymotrypsin is produced in the acinar cells of the pancreas as the inactive precursor, chymotrypsinogen.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service