Assay Method Information

Assay Name:  MNK2a In Vitro Kinase Assay 2
Description:  The inhibition of kinase activity of MNK2a was assessed using pre-activated GST-MNK2a. The white, 384-well OptiPlate F plates were purchased from PerkinElmer. The ADP-Glo Kinase Assay (including ultra pure ATP) was purchased from Promega (V9103). Activated MNK2a was obtained as described in WO2011/104340. The unlabeled eIF4E peptide (NH2-TATKSGSTTKNR-CONH2 (SEQ ID NO: 1)), differing from Seq. ID No. 5 of WO 2011/104340 by the C-terminal CONH2 group, was purchased from Thermo Fisher Scientific. All other materials were of highest grade commercially available. Compounds are tested in either serial dilutions or single dose concentrations. The compound stock solutions are 10 mM in 100% DMSO The serial compound dilutions are prepared in 100% DMSO followed by 1:27.3 intermediate dilution in assay buffer. The final DMSO concentration in assay will be <3%.In the 384-well plates 3 μl of test compound from the intermediate dilution is mixed with 4 μl of the activated MNK2 enzyme (final concentration of 10 nM) and 4 μl of the peptide (final concentration of 25 μM)/ultra pure ATP (final concentration of 20 μM), all dissolved in assay buffer. This step is followed by an incubation time of 90 min, then 10 μl of ADP Glo reagent are added, followed by 40 min of incubation. Then 20 μl of kinase detection reagent are admixed. The plates are sealed and after an incubation period of 30 min, the luminescence signal is measured in an Envision reader to determine the amount of produced ADP. All incubation steps are performed at room temperature. The assay buffer consists of 20 mM HEPES, 2 mM DTT, 0.01% BSA, 20 mM MgCl2 and 0.1% Pluronic F-127.Each assay microtiter plate contains wells with vehicle controls instead of compound (1% DMSO in water) as reference for the high signal (100% CTL, high signal), and wells containing a potent MNK2 inhibitor (final 20 μM, 1% DMSO) as reference for low signal (0% CTL, low signal).The luminescent signal generated is proportional to the ADP concentration produced and is correlated with activated MNK2 activity. The analysis of the data is performed by the calculation of the percentage of ATP consumption of activated MNK2 in the presence of the test compound compared to the consumption of ATP in the presence of activated MNK2 without compound. (RLU(sample)−RLU(low control))*100/(RLU(high value)−RLU(low control))[RLU=relative luminescence units]An inhibitor of the MNK2 enzyme will give values between 100% CTL (no inhibition) and 0% CTL (complete inhibition). Values of more than 100% CTL are normally related to compound/sample specific physico-chemical properties (e.g. solubility, light absorbance, fluorescence).
Affinity data for this assay
 

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