Molecular Weight(MW): 384.39
SB431542 is a potent and selective inhibitor of ALK5 with IC50 of 94 nM in a cell-free assay, 100-fold more selective for ALK5 than p38 MAPK and other kinases.
Cited by 129 Publications
Purity & Quality Control
Choose Selective TGF-beta/Smad Inhibitors
|Description||SB431542 is a potent and selective inhibitor of ALK5 with IC50 of 94 nM in a cell-free assay, 100-fold more selective for ALK5 than p38 MAPK and other kinases.|
SB 431542 inhibits the activin type I receptor ALK4 and the nodal type I receptor ALK7, which are responsible for the phosphorylation of Smad2. SB 431542 has little effect on ALK1, ALK2, ALK3, and ALK6, which show phosphorylation of Smad1. SB 431542 is a selective inhibitor of endogenous activin but has no apparent effect on BMP signaling. SB 431542 could induce both Smad2/Smad4- and Smad3/Smad4-dependent transcription.  In A498 cells, SB 431542 inhibits both TGF-β1-induced collagen Iα1 and PAI-1 mRNA with IC50 of 60 nM and 50 nM, respectively. In addition, SB 431542 inhibits production of TGF-β1-induced fibronectin mRNA and protein with IC50 of 62 nM and 22 nM, respectively.  SB 431542 blocks the TGF-β-mediated growth factors, including PDGF-A, FGF-2 and HB-EGF, leading to an increase in proliferation of MG63 cells. SB 431542 also inhibits TGF-β-induced c-Myc and p21 WAF1/CIP1.  SB 431542 significantly suppresses TGF-β-induced G1 arrest, leading to accumulation of cells in the S phase of the cell cycle in FET, RIE, and Mv1Lu cells. SB 431542 also inhibits TGF-β-induced epithelial to mesenchymal transition (EMT) in NMuMG and PANC-1 cells.  SB 431542 significantly elevates the expression of CD86 in BM-DCs and that of CD83 within CD11c+ cells suppressed by TGF-β. SB 431542 is able to induce NK activity through functional maturation and IL-12 production of human DCs. 
|In vivo||SB 431542 triggers cytotoxic T lymphocyte (CTL) activities in the colon-26 carcinoma models and is most likely to produce antitumor immunological outcomes through alteration of DC function suppressed by TGF-β. |
|Kinase Assay: ||
Flashplate assay for ALK5:SB 431542 is dissolved in DMSO at a concentration of 10 mM. The kinase domain of TGFβRI, from amino acid 200 to the C-terminus, and the full-length Smad3 protein are expressed as N-terminal glutathion S-transferase (GST) fusion proteins in the baculovirus expression system. Proteins are purified with glutathion Sepharose beads 4B. Basic FlashPlates are coated with 0.1 M sterile filtered sodium bicarbonate, pH 7.6, containing 700 ng of GST-Smad3 per 100 μL. Assay buffer contains 50 mM HEPES (pH 7.4), 5 mM MgCl2, 1 mM CaCl2, 1 mM DTT, 100 mM GTP, 3 μM ATP plus 0.5 μCi/well ɤ33P-ATP, and 85 ng of GST-ALK5 with or without SB 431542. Plates are incubated at 30 °C for 3 hours. The assay buffer is removed by aspiration, and the plate is counted on a Packard TopCount 96-well scintillation plate reader.
-  Callahan JF, et al. J Med Chem, 2002, 45(5), 999-1001.
-  Inman GJ, et al. Mol Pharmacol, 2002, 62(1), 65-74.
-  Laping NJ, et al. Mol Pharmacol, 2002, 62(1), 58-64.
|In vitro||DMSO||76 mg/mL (197.71 mM)|
|Ethanol||3 mg/mL (7.8 mM)|
|In vivo||Add solvents to the product individually and in order(Data is from Selleck tests instead of citations):
2% DMSO+30% PEG 300+ddH2O
For best results, use promptly after mixing.
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Frequently Asked Questions
I would appreciate it if you can help me in figuring out the formulation for this drug in vivo experiments.
S1067 SB431542 in 1% DMSO+30% polyethylene glycol+1% Tween 80 at 30 mg/ml is a suspension for oral gavage. It can also be dissolved in 2% DMSO+30% PEG 300+ddH2O at 5 mg/ml as a clear solution for IP injection.