Description:

rEK is recombination preparation of the catalytic subunit of bovine enterokinase (EC 3.4.21.9). rEK is secreted expressed and isolated from the yeast Pichia pastoris to yield a highly purified enzyme preparation. rEK recognizes the sequence Asp-Asp-Asp-Asp-Lys↓ and cleaves the peptide bond after the lysine residue. rEK is secreted glycosylated protein without polyhistidine tag, and its molecular weight is approaching 30 KDa. The enzyme can be use to cleave any fusion protein that carries this peptide sequences.
The optimal temperature for cleavage is 30°C; however, the enzyme can be used at temperatures as low as 4°C.

Components:
ME___ rEK (recombinant bovine enterokinase)
ME___ 10X rEK Buffer

Unit Definition:
One unit of rEK is the amount of enzyme required to digest 40μg of a thioredoxin-X fusion protein to 90% completion in 8 hours at 37℃, in 16 hours at 25℃ or in 22 hours at 4℃.

Store rEK at -70°C for long term or at -20°C for < 1 year.
Store 10X rEK Buffer at 4°C, -20°C or -70°C

Storage Buffer:
50mM Tris-Cl(pH 8.0), 50% (v/v) glycerol

10X Reaction buffer:
500mM Tris-Cl(pH 8.0), 10mM CaCl2, 1% Tween20