For research use only.
CAS No. 301836-41-9
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.
Selleck's SB431542 has been cited by 356 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.
* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.
In vivo Formulation Calculator (Clear solution)
|Step 1: Enter information below (Recommended: An additional animal making an allowance for loss during the experiment)|
|Dosage||mg/kg||Average weight of animals||g||Dosing volume per animal||ul||Number of animals|
|Step 2: Enter the in vivo formulation ()|
|% DMSO % % Tween 80 % ddH2O|
Working concentration： mg/ml；
Method for preparing DMSO master liquid: ： mg drug pre-dissolved in μL DMSO (Master liquid concentration mg/mL，)
Method for preparing in vivo formulation：Take μL DMSO master liquid, next addμL PEG300， mix and clarify, next addμL Tween 80，mix and clarify, next add μL ddH2O，mix and clarify.
1.Please make sure the liquid is clear before adding the next solvent.
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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.