Principle

Protino® Glutathione Agarose 4B enables fast and convenient purification of recombinant Glutathione-S-Transferase (GST)-tagged proteins from whole cell extracts by affinity chromatography.

Binding of protein is based on the selective interaction between the Glutathione-S-Transferase tag of the recombinant protein and the immobilized glutathione of the affinity resin. The Glutathione-S-Transferase tag is a large affinity tag consisting of 220 amino acids (26 kDa) forming dimer structures. The binding process is highly specific and selective as it is based on enzyme-substrate reaction between GST and its substrate glutathione, a tripeptide. Thus, only one chromatographic step leads to a high degree of purification. Elution of the GST-tagged protein is performed with free glutathione in the elution buffer. The affinity of Glutathione-S-Transferase for free glutathione is higher than the one for the immobilized glutathione bound to the agarose matrix. Therefore free glutathione replaces the
immobilized glutathione which leads to release of the GST-tagged protein from the matrix.

Protino® Glutathione Agarose 4B is suitable for batch binding as well as FPLC applications. The material is based on 4 % beaded agarose with immobilized glutathione. It withstands incubation in 0.1 M acetate pH 4, 0.1 M NaOH, 70 % ethanol, or 6 M guanidine hydrochloride without significant loss of protein yield.

Features

* Binding capacity will vary for each GST-tagged protein
** Slow flow rates are recommended for the loading step to allow maximal binding of the GST-tagged protein