α-Chymotrypsin from bovine pancreas

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

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

Featured Industry

Diagnostic Assay Manufacturing

storage temp.


Gene Information

cow ... CTRB1(618826)

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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


Target Organs

Respiratory system

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


NONH for all modes of transport

WGK Germany


  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.

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

    Ask a Scientist here.

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...
Gang Huang et al.
Nature communications, 8(1), 935-935 (2017-10-19)
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Joost Snijder et al.
Immunity, 48(4), 799-811 (2018-04-19)
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Elisa Sassetti et al.
International journal of molecular sciences, 20(11) (2019-06-05)
The serine protease Caseinolytic protease subunit P (ClpP) plays an important role for protein homeostasis in bacteria and contributes to various developmental processes, as well as virulence. Therefore, ClpP is considered as a potential drug target in Gram-positive and Gram-negative...
Xingchen Chen et al.
Marine drugs, 17(12) (2019-12-18)
Serine proteases play pivotal roles in normal physiology and a spectrum of patho-physiological processes. Accordingly, there is considerable interest in the discovery and design of potent serine protease inhibitors for therapeutic applications. This led to concerted efforts to discover versatile...
Analytical Enzyme Chymotrypsin: Chymotrypsin is produced in the acinar cells of the pancreas as the inactive precursor, chymotrypsinogen.
Read More
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.
Read More

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