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. This product is a high-purity, high-specific activity enterokinase prepared using a recombinant E.coli. It boasts a broad range of applicability (operating temperature: 4-45°C; pH range: 4.5-9.5) and retains partial activity in the presence of various detergents and denaturants.

Storage Solution: 5 U/μL hEK-His in20 mM Tris-HCl, 200 mM NaCl, 2 mM CaCl2, pH 7.4 @ 25°C

Optimal incubation times and enzyme concentrations must be determined empirically for a particular substrate. Typical reaction conditions are as follows:
Combine 500 ug of sample with reaction buffer
Recommended Reaction Buffer: 20 mM Tris-HCl, 50 mM NaCl, 2 mM CaCl2 (pH 8.0)
Add 1 U of Enterokinase light chain
Incubate at 25°C for 16 hours

1. Enterokinase is inhibited by high salt concentrations. For optimal activity NaCl concentration should be 50 mM or less. The pH of the buffer should be between 6 and 9. The enzyme requires 2 mM Calcium for activity.