• My NEB
  • Print
  • PDF
  • Enterokinase, light chain


    Enterokinase is a specific protease that cleaves after lysine at its cleavage site Asp-Asp-Asp-Asp-Lys. It will sometimes cleave at other basic residues, depending on the conformation of the protein substrate. Enterokinase will not cleave at site followed by proline.

    Product Source

    This preparation is purified from k. lactis containing a clone of the light chain of the bovine enterokinase gene (1,2).

    Properties and Usage

    Unit Definition

    0.00016 ug of Enterokinase will cleave 25 ug of test substrate to 95% completion in 16 hours or less at 25°C.

    Unit Assay Conditions:

    20 mM Tris-HCl (pH 8.0 @ 25°C), 50 mM NaCl, 2 mM CaCl2, 25 ug of an MBP fusion protein test substrate and enzyme. Incubate at 23°C

    Storage Temperature


    Storage Conditions

    20 mM Tris-HCl
    200 mM NaCl
    2 mM CaCl2
    50% Glycerol
    pH 7.2 @ 4°C

    Molecular Weights

    Apparent: 31 kDa
    Theoretical: 26.3 kDa


    1. Suggested Reaction Conditions: The amount of enzyme required to cleave a fusion protein in a 16 hour reaction at room temperature ranges from 0.0001% to 0.5% (w/w). Cleavage of an MPB-paramyosin-ΔSal fusion protein with an enterokinase site requires 0.0006%.
    2. Removal: Enterokinase will bind specifically to trypsin inhibitor agarose (e.g., Sigma T-0637).


    1. Collins-Racie, L.A. et al (1995). Biotechnology. 13, 982-987.
    2. Taron, C. and Colussi, P. Unpublished observation

    Supporting Documents

    Material Safety Datasheets

    The following is a list of Material Safety Data Sheets (MSDS) that apply to this product to help you use it safely. The following file naming structure is used to name these document files: [Product Name] MSDS. For international versions please contact us at info@neb.com.


    The Product Summary Sheet, or Data Card, includes details for how to use the product, as well as details of its formulation and quality controls. The following file naming structure is used to name the majority of these document files: [Catalog Number]Datasheet-Lot[Lot Number]. For those product lots not listed below, please contact NEB at info@neb.com or fill out the Technical Support Form for appropriate document.

    Selection Tools