| 激酶實(shí)驗(yàn) | In vitro kinase assays : Kinase assays for Akt2, PKA, p70S6K, and CDK2/cyclin A are all carried out in a radiometric filter binding format. Assay reactions are set up in the presence of AT7867. For Akt2, the Akt2 enzyme and 25 μM Aktide-2T peptide (HARKRERTYSFGHHA) are incubated in 20 mM MOPS (pH 7.2), 25 mM β-glycerophosphate, 5 mM EDTA, 15 mM MgCl2, 1 mM sodium orthovanadate, 1 mM DTT, 10 μg/mL bovine serum albumin, and 30 μM ATP (1.16 Ci/mmol) for 4 hours. For PKA, the PKA enzyme and 50 μMpeptide (GRTGRRNSI) are incubated in 2 mM MOPS (pH 7.2), 25 mM β-glycerophosphate, 5 mM EDTA, 15 mM MgCl2, 1 mM orthovanadate, 1 mM DTT, and 40 μM ATP (0.88 Ci/mmol) for 20 minutes. For p70S6K, the p70S6K enzyme and 25 μMpeptide substrate (AKRRRLSSLRA) are incubated in 10 mM MOPS (pH 7), 0.2 mM EDTA, 1 mM MgCl2, 0.01% β-mercaptoethanol, 0.1 mg/mL bovine serum albumin, 0.001% Brij-35, 0.5% glycerol, and 15 μM ATP (2.3 Ci/mmol) for 60 min. For CDK2, the CDK2/cyclin A enzyme and 0.12 μg/mL histone H1 are incubated in 20 mM MOPS (pH 7.2), 25 mM β-glycerophosphate, 5 mM EDTA, 15 mM MgCl2, 1 mM sodium orthovanadate, 1 mM DTT, 0.1 mg/mL bovine serum albumin, and 45 μM ATP (0.78 Ci/mmol) for 4 hours. Assay reactions are stopped by adding an excess of orthophosphoric acid, and the stopped reaction mixture is then transferred to Millipore MAPH filter plates and filtered. The plates are then washed, scintillant is added, and radioactivity is measured by scintillation counting on a Packard TopCount. IC50 values are calculated from replicate curves using GraphPad Prism software. Akt1 and Akt3 enzyme assays are carried out. |