Enterokinase Protein, Bovine (P.pastoris, His)

Enterokinase Protein, Bovine (P.pastoris, His) is a single glycosylated polypeptide chain with His tag. Enterokinase plays a role of turning trypsinogen to its active form trypsin.

Bovine enterokinase is a serine protease and functions as the physiological activator of trypsinogen. The amino acid composition shows that the light chain has nine half-cystine residues and that one half-cystine was in a disulfide link between the light and heavy subunits. The sequence has homologies with other serine proteases containing one or two chains. The homologies suggest that the catalytic subunit has the same three-dimensional structure and, therefore, the same mechanism of enzymatic action as pancreatic chymotrypsin, trypsin, and elastase. The presence of the conserved amino-terminal activation peptide sequence (IVGG) shows that enterokinase must have a zymogen precursor and that the two-chain enzyme arises from limited proteolysis during posttranslational processing^[1].

100 IU/μg Unit Definition: One unit is defined as the amount of enzyme needed to cleave 50 μg of fusion protein in 16 hours to 95% completion at 22°C in a buffer containing 25mM Tris-HCl, pH 8.0.

Bovine

P. pastoris

C-His

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Approximately 40 kDa

Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized after extensive dialysis against 20 mM Tris-HCl, pH 7.4, 200 mM NaCl, 2 mM CaCl₂.

<0.2 EU/μg, determined by LAL method.

Reconstitute at 1 mg/mL in sterile deionied water, then dilute in sterile EK Storage Buffer (20 mM Tris-HCl, pH 7.4, 200 mM NaCl, 2 mM CaCl₂).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Light A, et al. The amino-terminal sequence of the catalytic subunit of bovine enterokinase. J Protein Chem. 1991 Oct;10(5):475-80.  [Content Brief]