Description

Enterokinase (EC 3.4.21.9) is a serine protease produced by cells in the duodenal wall. It specifically recognizes and cleaves proteins or polypeptides at the sequence -Asp-Asp-Asp-Asp-Lys-↓-X. Natural bovine enterokinase consists of a heavy chain (800 amino acids) and a light chain (235 amino acids). This product features the light chain of bovine enterokinase in a monoglycosylated form, expressed recombinantly in Pichia pastoris and purified using high-performance chromatography. It includes a 6× His-tag, with a molecular weight of 43kDa. The optimal enzymatic cleavage pH is 4.5–9.5, and the optimal cleavage temperature is 25°C. Recombinant enterokinase activity is inhibited to varying degrees by imidazole, sodium chloride, glycerol, and phosphate.

Applications

• Biopharmaceuticals: Removal of fusion proteins located at the N-terminus of target proteins or polypeptides during the production process of fusion peptides or proteins.

Quality Parameters

• Appearance: White or off-white lyophilized powder
• Electrophoresis (SDS-PAGE): ≥95%
• Specific Activity: ≥250 U/mg

Notes: 

① Additional tests such as microbial limits, host protein residue, or host DNA residue can be added to the CoA as per customer requirements. 

② Enzyme activity definition: One unit of activity is defined as the enzyme amount required to cleave 95% of 50μg of GST-VAS fusion protein containing the enterokinase cleavage site within 16 hours under the conditions of 25°C and pH 8.0.

Advantages

• Manufactured under GMP-compliant conditions with a batch production scale of up to 100g and an annual output reaching kilogram levels. Quality is consistent across production batches.
• High purity, high enzymatic activity, and excellent cleavage specificity with no contaminant enzymes. No animal-derived materials are used in the production process.

Storage 

The lyophilized powder is stable for 24 months when stored below -15°C. After reconstitution, it can be aliquoted and stored below -15°C with stability over three freeze-thaw cycles. Reconstituted solutions can be stored at 2–8°C for up to three days.