Enterokinase (EK) is an amino protease existing in duodenum of mammal and is involved in digestion. It consists of a disulfide-linked 82–140 kDa heavy chain which anchors enterokinase in the intestinal brush border membrane and a 35–62 kDa light chain which contains the catalytic subunit. Additionally, both of the chains are derived from a single precursor that is cleaved by a trypsin-like protease. EK can specially recognize the amino acid sequence DDDDK, and digest the peptide bond after the lysine residue.
rEK was report to be more effective than nature EK in cleaving recombinant proteins. Furthermore, the light chain possesses the whole enzyme activity of EK.
rBoEK has the highest activity than EK of other species and is used wildly in biochemical applications. rBoEK with 6 × His-tag binds with Ni2+ affinity chromatography and was designed for removing from digestion system.
Source
Escherichia coli.
Molecular Weight
Approximately 28 kDa, a single non-glycosylated polypeptide chain containing 241 amino acids，with 6 × His at C-terminus.
Biological Activity
Appearance
Sterile liquid.
Formulation
50 mM Tris-HCl, pH 8.0, 0.5 M NaCl and 50 % glycerol.
Endotoxin
Less than 1 EU/ug of rBoEKL, His as determined by LAL method.
Reconstitution
Stability and Storage
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.- 6 months from date of receipt, -20 to -70 °C as supplied.- 3 months, -20 to -70 °C under sterile conditions after opening.
