Assay Method Information

Assay Name:  In Vitro Kinase Activities (LRRK2 TR-FRET Peptide Assay)
Description:  Compounds as described herein (compounds of Formula I, e.g., compounds of the above Examples) are tested for their in vitro kinase activities using various LRRK2 (including LRRK2 G2019S mutant) assays. For example, assays were performed in a total volume of 20 μL using the same kinase reaction buffer (50 mM HEPES pH 7.5, 10 mM MgCl2, 1 mM EGTA, 2 mM DTT and 0.01% Tween-20) for wild-type or G2019S mutant LRRK2. Serially diluted compounds (1% DMSO as co-solvent) were pre-incubated with recombinant GST-LRRK2 (wild-type, or G2019S mutant, Invitrogen) for 15 minutes at room temperature in 384-well Corning black plates. Mixtures of ATP and biotin-LRRKtide substrate (biotin-RLGRDKYKTLRQIRQ) (SEQ ID NO: 1) were added to the wells at a final concentration of 100 μM ATP and 100 nM substrate, with final kinase concentration of 10 nM. The kinase reactions were carried out at room temperature for 60 minutes, then the reaction was stopped with the addition of 10 μL/well of stop/detection buffer (25 mM HEPES pH 7.5, 66 mM EDTA, 0.8 M KF and 0.1% BSA) that contains streptavidin-XL665 (12.5 nM) and europium-conjugated phospho-specific antibody (2nM). The plates were read 1 hour later and the time-resolved fluorescence (665 nm to 615 nm ratio) measured using an Envision reader. The inhibition of each well was calculated using the control and background readings for that plate. IC50 values were determined from dose-response curves using eight concentrations from the serial dilution of the test compounds.Many compounds of the Examples are demonstrated to be inhibitors of LRRK2, with most of the compounds tested typically measuring an IC50 below 1 μM for both LRRK2 and G2019S mutant LRRK2 kinase activity.
Affinity data for this assay
 

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