Recombinant proteins containing the SBP-Tag bind to streptavidin and this property may be utilized in specific purification, detection or immobilization strategies.
[2] The SBP-Tag has been shown to bind streptavidin with an equilibrium dissociation constant of 2.5nM[1][2] and is readily eluted with biotin under native conditions.
[1][2] Because of the mild elution conditions (biotin plus wash buffer) SBP-Tagged proteins can be generated in a relatively pure state with a single purification step.
[1][3][4] There are several relatively abundant mammalian proteins that inherently associate with the IMAC matrices that bind to the more commonly used Polyhistidine-tag (His-tag).
For this reason non-IMAC purification protocols, including with the SBP-Tag, are often preferred for proteins that are expressed in mammalian cells.