Does Strep II tag binding to streptavidin?
The Strep-tag ®II binds specifically to the engineered streptavidins, Strep-Tactin ® and Strep-Tactin ®XT, by occupying the binding pocket of the natural ligand biotin.
What is Streptactin?
The Strep-tag® system is a method which allows the purification and detection of proteins by affinity chromatography. This peptide sequence exhibits intrinsic affinity towards Strep-Tactin®, a specifically engineered streptavidin, and can be N- or C- terminally fused to recombinant proteins.
Does streptavidin bind Streptag?
The strep-tag has the property of binding to streptavidin competitively with biotin. This behavior permits the use of very gentle conditions for the elution of a bound strep-tag fusion protein from the streptavidin affinity column, just by applying a diluted solution of biotin or one of its chemical derivatives.
Does streptavidin bind DNA?
The protein of interest binds to the DNA, and then this complex binds (via the biotin moiety) to the tetrameric protein streptavidin. Since streptavidin is multivalent, it is able to serve as a bridge between the biotinylated DNA fragment and the biotin-containing resin.
What is Desthiobiotin?
Desthiobiotin is a biotin analogue that binds less tightly to biotin-binding proteins and is easily displaced by biotin. We synthesized an amine-reactive desthiobiotin derivative for labeling proteins and a desthiobiotin-agarose affinity matrix.
How does strep Tactin work?
The Strep•Tag® system is based on the reliable biotin/streptavidin binding specificity. The small Strep•Tag® II peptide is an eight amino acid fusion tag with binding specificity comparable to biotin. The small size of the tag reduces potential interference with target protein structure or function.
What is strep Tactin resin?
Strep-Tactin ® Sepharose ® is a 4% agarose coupled with the streptavidin variant Strep-Tactin ® and applicable for purification of Strep-tag ®II or Twin-Strep-tag ® fusion proteins. The wide-meshed polymer allows for the simple attachment of larger proteins to the stationary phase.
Which is more binding streptavidin or Strep tag?
The binding affinity of Strep-tag to Strep-Tactin is nearly 100 times higher than to Streptavidin. The so-called Strep-tag system, consisting of Strep-tag and Strep-Tactin, has proven particularly useful for the functional isolation and analysis of protein complexes in proteome research.
Is the Strep-tag II a minimal peptide sequence?
The Strep-tag II is an eight-residue minimal peptide sequence (Trp-Ser-His-Pro-Gln-Phe-Glu-Lys) that exhibits intrinsic affinity toward streptavidin and can be fused to recombinant proteins in various fashions. We describe a protocol that enables quick and mild purification of corresponding Strep-ta …
Which is affinity receptor does Strep Tactin bind to?
The affinity receptor for Strep-tag®II is affinity engineered streptavidin, named Strep-Tactin®. Strep-tag®II binds to the biotin binding pocket enabling mild competitive elution with biotin derivatives, preferably desthiobiotin, for repeated use of the Strep-Tactin® affinity resins.
Why does Strep tag fusion protein bind non specific proteins?
This is due to its extraordinary low tendency to bind proteins non specifically. Then, the purified Strep-tag fusion protein is gently eluted with a low concentration of desthiobiotin, which specifically competes for the biotin binding pocket (step 3).