||Several key growth factors, cytokines, and protooncogenes transduce their growth- and differentiationpromoting signals through the mitogen-activated protein kinase or extracellular signal-regulated protein kinase (ERK) cascade. MAP (mitogen-activated protein) kinases are activated by a family of dual specificity kinases called MEKs (MAP kinase/Erk Kinase). MEK1 can be activated by Raf by phosphorylation on serine 218 and serine 222. Mutation of these sites to acidic residues leads to constitutively active MEK1 in some cases. Given the central role of the ERK/mitogen-activated protein kinase pathway in mediating growth-promoting signals for a diverse group of upstream stimuli, inhibitors of MEK, as a key central mediator, could have significant clinical benefit in the treatment of breast and other cancers. The human recombinant MEK1, activated by two amino acid exchanges (S218D, S222D), was expressed inE. coliand purified by gluthatione sepharose and gelfiltration. It is suitable for labeling MEK1 substrates and for activation of ERK1 and ERK2. The molecular weight of the protein is 69.7 kDa. The GST-Tag facilitates the protein‘s application in typical GST pull-down assays.
||Supplied in 50 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.1 mM EGTA, 270 mM sucrose and 1 mM DTT.
||> 90% by SDS-PAGE.
||> 250.000 U/mg (1 Unit is defined as the amount of MEK1 which activates unactive ERK1 (0.3 mg/ml) by 1 U/min using 100 μM ATP at 30°C. 1 U ERK1 activity is defined as 1 pmol phosphate transferred to myelin basic protein (0.2 mg/ml) per min using 125 μM ATP at 30°C).
||For in vitro use only.
||Quality guaranteed for 12 months store at - 80°C. Avoid freeze / thaw cycles.