Glutathione agarose; ~48% by SDS-PAGE and Coomassie blue staining. N-terminal GST-tagged recombinant human B-Raf residues 416-end, containing a V599E mutation. Expressed by baculovirus in Sf21 insect cells. Specific Activity: ~50,000U/mg 1 unit of B-Ra=1 unit of MAPK2(m) activity which in turn is equivalent to 1nmol phosphate incorporated into 0.33mg/ml myelin basic protein per minute at 30°C wtih a final ATP concentration of 100uM. Determined by a triple linked assay which involves the activation of MEK1(h) by B-Raf, followed by the subsequent activation of MAPK2(m) by the activated MEK1(h). Applications: MS Tryptic Fingerprint: Confirmed identity as B-Raf with ~30% amino acid coverage of the translated native sequence.