Kinase Assay: Pharmacol 2002, 62 58-62) The compounds named in the specified Examples were tested as follows for inhibition of ALK-5 autophosphorylation activity and of the ALK-5 phosphorylation of α-Casem Materials. Buffer 50 mM HEPES, pH 76, with 10 mM NaCI, 10 mM MgCI2, and 1 mM DTT GST-ALK-5 protein - 0 44 mg/ml (roughly 7 μM stock) A 1 350 dilution gives a 20 nM stock, which translates to 2 nM final in assay Human ALK-5 was expressed in Sf9 insect cells infected with Bacul ovirus expressing a ALK-5 truncation sequence (amino acids H149 -M503), fused at the N-terminus to Glutathione S-transferase GST, in a pFastBac vector (Invitrogen) The cells were disrupted by sonication at 4 0C The lysate was centrifuged at 40,000 x g for 45 minutes, and the supernantant applied to a 10 ml column of Glutathione Sepharose 4 Fast Flow (AmershamBioscienses) equilibrated with 100 mM Tπs-HCI pH 76 buffer containing 300 mM NaCI, 10% glycerol, 1 % NP40, 2 mM dithiothreitol (DTT) and one Protease...
ALK-5 Kinase Assay: In a 96 well filter-bottom plate (Millipore, #MSDV N6B 50), 58 ul Assay Buffer (50 mM HEPES, pH 7.6, with 10 mM NaCl, 10 mM MgCl2, and 1 mM DTT ) is added to reach well. Add 10 ul of Cold ATP mix in Assay Buffer, then 10 ul of a 1:10 dilution of alpha-Casein stock. Then add 2 ul of compound being tested (DMSO) at a 50x final concentration. Hot ATP mix (10 ul) is added, and the reaction is started with the addition of 10 ul of a 1:350 dilution of the ALK-5 protein (2 nM final) in Assay Buffer with 0.05% BSA (Bovine Serum Albumin). The reaction is mixed for 5 minutes at room temperature, and then continued for 145 minutes at room temperature. The reaction is then stopped with the addition of 100 ul of ice-cold 20% TCA (trichloroacetic acid). The assay is then incubated for at least 1 hour at 4° C., and then the contents of each well are filtered by suction through the filter. The wells are washed three times with 200 ul ice-cold 10% TCA. The plate bottom is blotted before and after removing plastic sub-base, and dried overnight at room temperature. Add 30 ul of scintillation fluid, and count 1 minute per well on a Wallac Tri-Lux scintillation counter.
ALK-5 Gene : ALK-5 gene reporter assay methods have been described in the art (see e.g., Maliekal et al. (2004) J Biol Chem 279(35):36287-36292). The compounds named in the specified Examples were tested as follows for inhibition of Smad binding element (SBE) luciferase reporter activity in TGFbeta1 stimulated NIH-3T3 cells. The following luciferase assay employs NIH/3T3 (murine fibroblast) cells, which are transiently transfected with a Smad binding element (SBE) luciferase reporter construct. This expressed construct is responsive to agents that stimulate the Smad signaling pathway.