Assay Method Information

Assay Name:  Kinase Assay
Description:  His-tagged human recombinant kinase full-length Akt2 expressed in insect cells and activated by PDK1 was purchased form Invitrogen (part number PV 3975). As substrate for the kinase reaction the biotinylated peptide biotin-Ahx-KKLNRTLSFAEPG (C-terminus in amide form) was used which can be purchased e.g. from the company Biosynthan GmbH (Berlin-Buch, Germany). For the assay 50 nl of a 100 fold concentrated solution of the test compound in DMSO was pipetted into a black low volume 384 well microtiter plate (Greiner Bio-One, Frickenhausen, Germany), 2 μl of a solution of Akt2 in assay buffer [50 mM TRIS/HCl pH 7.5, 5 mM MgCl2, 1 mM dithiothreitol, 0.02% (v/v) Triton X-100 (Sigma)] were added and the mixture was incubated for 15 min at 22° C. to allow pre-binding of the test compounds to the enzyme before the start of the kinase reaction. Then the kinase reaction was started by the addition of 3 μl of a solution of adenosine-tri-phosphate (ATP, 16.7 μM=>final conc. in the 5 μl assay volume is 10 μM) and substrate (1.67 μM=>final conc. in the 5 μl assay volume is 1 μM) in assay buffer and the resulting mixture was incubated for a reaction time of 60 min at 22° C. The concentration of Akt2 in the assay was adjusted depending of the activity of the enzyme lot and was chosen appropriate to have the assay in the linear range, typical enzyme concentrations were in the range of about 0.2 ng/μl (final conc. in the 5 μl assay volume). The reaction was stopped by the addition of 5 μl of a solution of HTRF detection reagents (200 nM streptavidine-XL665 [Cisbio] and 1.5 nM anti-phosho-Serine antibody [Millipore, cat. #35-001] and 0.75 nM LANCE Eu-W 1024 labeled anti-mouse IgG antibody [Perkin Elmer]) in an aqueous EDTA-solution (100 mM EDTA, 0.1% (w/v) bovine serum albumin in 50 mM HEPES/NaOH pH 7.5). The resulting mixture was incubated 1 h at 22° C. to allow the binding of the biotinylated phosphorylated peptide to the streptavidine-XL665 and the antibodies.
Affinity data for this assay
 

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