Product Uses

• Study of G13S K-Ras4B exchange activity with different GEFs

• Identification of G13S K-Ras4B exchange factors (GEFs)

• Positive control for GEF studies

• Biochemical characterization of G13S K-Ras4B protein interactions

• Western blot standard

Materials

The G13S (glycine to serine at amino acid position 13) mutant human K-Ras4B protein has been produced in a bacterial expression system. The recombinant protein contains six histidine residues at its amino terminus (His-tag). The molecular weight of 6xHis tagged G13S K-Ras4B is approximately 25 kDa and it is supplied as a white lyophilized powder.

Storage

Before reconstitution, briefly centrifuge to collect the product at the bottom of the tube. The protein should be reconstituted to 5 mg/ml with the addition of 20 μl of ice cold nanopure water (100 μg size). When reconstituted, the protein will be in the following buffer: 50 mM Tris pH 7.5, 50 mM NaCl, 0.5 mM MgCl2, 5% (w/v) sucrose, and 1% (w/v) dextran. In order to maintain high biological activity of the protein, it is strongly recommended that the protein solution be supplemented with DTT to 1 mM final concentration, aliquoted into "experiment-sized" amounts, snap frozen in liquid nitrogen, and stored at -70°C. The protein is stable for six months if stored at -70°C. The protein should not be exposed to repeated freeze-thaw cycles. The lyophilized protein is stable at 4°C desiccated (<10% humidity) for one year.