SB 431542 is a potent and selective inhibitor of the TGF-B1 receptor ALK5 (IC50 = 94 nM)1. It inhibits ALK4 only at higher concentrations (IC50 = 140nM). It is a less potent antagonist of ALK4 (IC50 = 140 nM)2 and ALK7.3 It does not affect the BMP receptors ALK2, ALK3, ALK6, or a panel of other kinases tested.3 SB 431542 specifically blocks Smad signaling, reducing gene expression relevant to fibrosis and cancer.3 Through its effects on ALK/Smad signaling, SB 431542 suppresses renewal in embryonic and induced pluripotent stem cells and promotes their differentiation.4,5Molecular Weight:~384.39Solubility:DMSO: 10mg/ml, solubleH2O: InsolubleStorage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
