U-0126, 1 mg

Provided by STEMCELL Technologies, this small molecule is a selective, non-ATP competitive inhibitor of mitogen-activated protein kinase kinase (MEK), targeting both MEK1 and MEK2 with reported IC₅₀ values of 72 nM and 58 nM, respectively. It shows little or no inhibition at micromolar levels of other kinases such as ERK, protein kinase C (PKC), c-Jun N-terminal kinases (JNK), other MAP kinase kinases (MKK3, MKK4, MKK6), cyclin-dependent kinases (CDK2, CDK4), ABL, and RAF. The compound also antagonizes AP-1 transcription and selectively inhibits promoters containing AP-1 response elements.

The chemical name is 2,3-bis[amino[(2-aminophenyl)thio]methylene]-butanedinitrile, with CAS Number 109511-58-2, chemical formula C₁₈H₁₆N₆S₂, and molecular weight 380.5 g/mol. It is supplied as a crystalline solid with a stated purity of ≥ 98%. Reported solubilities are approximately 0.3 mg/mL in a 1:2 solution of DMF:PBS (pH 7.2), 0.5 mg/mL in ethanol, 25 mg/mL in DMSO, and 30 mg/mL in DMF. The product is stable at -20°C as supplied and should be protected from prolonged exposure to light. Stock solutions can be prepared in DMSO at up to 65 mM and in absolute ethanol at up to 1 mM. The compound has low solubility in aqueous media, and when used as a cell culture supplement the stock should be diluted into culture medium immediately before use, with a final DMSO concentration kept below 0.1% due to potential cell toxicity.

Published applications include maintenance of human pluripotent stem cells in combination with FGF2, Activin A, and a PKC inhibitor; inhibition of T-cell proliferation against certain antigenic stimuli by reducing IL-2 mRNA levels; neuroprotection in a gerbil ischemia model and in primary mouse neurons cultured under hypoxia; inhibition of glutamate-induced oxidative stress in mouse hippocampal HT22 cells and rat primary cortical cultures; and activation of peroxisome proliferator-activated receptor (PPAR) co-activator 1α (PGC-1α) with prevention of neurotoxicity and spatial memory impairment in amyloid-β-challenged rats. The product is described as neuroprotective in normal and Alzheimer's disease model cells. Products are for research use only and are not intended for human or animal diagnostic or therapeutic uses unless otherwise stated.