Shanghai Kekai Biotechnology Co., Ltd.

Recombinant enterokinase
High specificity and high purity
1. Product introduction
Enterokinase is a high-purity recombinant bovine enterokinase. The enzyme is HPLC-purified, pure, specific, and contains no other proteases. Enterokinase (EC 3.4.21.9) is a specific protease that cleaves the lysine carboxyl terminal site containing four aspartic acid in front: aspartic acid-aspartic acid-aspartic acid-aspartic acid-aspartic acid-lysine. Enterokinase removes fusion proteins located at the N-terminus of proteins to remove unwanted fusion tags.
High specificity
1) Specific proteases that cleave the lysine carboxyl terminal sites containing four aspartic acid in front: aspartic acid - aspartic acid - aspartic acid - aspartic acid - lysine (DDDDK)
2) No other proteases, no non-specific cleavage
Figure 1: SDS-PAGE test results, a single main band of purified enterokinase
Figure 2: 1U of EK is applied to SDS-PAGE analysis after 0min, 10min, 20min, 30min, 40min, 50min, and 60 min of 50ug substrate
Figure 3: 1U, 2U, 5U, 10U EK acting on 50ug substrate after 4h and 1U EK acting on SDS-PAGE analysis after 50ug substrate 16h

Digestion conditions:
According to the definition of enzyme activity, the recombinant EK digestion conditions are examples: In the 25mM Tris-HCl 8.0 system:
Fusion protein concentration 0.1-1mg/ml (total protein 50-100μg)
Recombinant EK dosage 1-2U
Temperature 25°C
Overnight digestion, or complete digestion, takes 12h-16h.

Common factors affecting enterokinase activity
At > 200 mM imidazole, or > 200 mMNaCl, or > 5% glycerol, the digestion effect is affected. Enzymatic digestion can be performed according to the following recommended methods:
1) For optimal digestion results, dialyze the sample into 25 mM Tris-HCl 8.0 buffer before digestion.
2) If dialysis is inconvenient, the sample can be diluted, the imidazole content is below 100mM, the NaCl concentration is below 50mM, and the glycerol concentration is less than 5% for enzymatic digestion, and the ratio of enzyme dosage to protein remains unchanged (that is, 50μg of protein is digested in 1U).
3) If the sample solution contains one or more of the above components, and it is inconvenient to remove, at this time, appropriately increase the amount of enzyme or prolong the digestion time, and can also achieve a better digestion effect.

3. Product use
Used to remove fusion proteins located at the N-terminus of proteins to remove unwanted fusion tags

Model:KK-T008
CAS: 9014-74-8
EC:3.4.21.9
Company name: Shanghai Kekai Biotechnology Co., Ltd