Kinase Activity Assay: The kinase reaction buffer consists of 50 mM Tris pH 8.5, 0.01% BRIJ-35, 10 mM MgCl2, 1 mM EGTA, and 2 mM DTT. In the assay, 1 nM LRRK2 WT or 250 pM LRRK2 G2019S kinase is incubated with the test compound (typically at 0 to 30 μM) for 30 minutes before the kinase reaction is initiated by addition of 1.3 mM ATP and 0.4 μM fluorescein-LRRKtide. The reaction mixture (20 μl total volume) is incubated for 2 hours at 30 °C. before the reaction is terminated by addition of 10 mM EDTA and 1 nM terbium-labelled anti-phospho-LRRKtide antibody (final volume 20 μl). The mixture is further incubated for 30 minutes at RT. TR-FRET is measured by excitation of the terbium-donor with 340 nm light and subsequent (delay time 100 μs) measurement of terbium and fluorescein emission at 495 nm and 520 nm, respectively, over a time window of 1000 μs. The measurement is repeated 10 times for fluorescein and 10 times for terbium emission with a 2000 μs time window between repeats. TR-FRET measurements are performed on a Biomek Synergy plate. The TR-FRET signal is calculated as the emission-ratio at 520 nm over 495 nm.
Kinase Activity Assay: The kinase reaction buffer consists of 50 mM Tris pH 8.5, 0.01% BRIJ-35, 10 mM MgCl2, 1 mM EGTA, and 2 mM DTT. In the assay, 1 nM LRRK2 WT or 250 pM LRRK2 G2019S kinase is incubated with the test compound (typically at 0 to 30 μM) for 30 minutes before the kinase reaction is initiated by addition of 1.3 mM ATP and 0.4 μM fluorescein-LRRKtide. The reaction mixture (20 μl total volume) is incubated for 2 hours at 30 °C. before the reaction is terminated by addition of 10 mM EDTA and 1 nM terbium-labelled anti-phospho-LRRKtide antibody (final volume 20 μl). The mixture is further incubated for 30 minutes at RT. TR-FRET is measured by excitation of the terbium-donor with 340 nm light and subsequent (delay time 100 μs) measurement of terbium and fluorescein emission at 495 nm and 520 nm, respectively, over a time window of 1000 μs. The measurement is repeated 10 times for fluorescein and 10 times for terbium emission with a 2000 μs time window between repeats. TR-FRET measurements are performed on a Biomek Synergy plate. The TR-FRET signal is calculated as the emission-ratio at 520 nm over 495 nm.
Inhibition of recombinant human LRRK2 (970 to 2527 residues) G2019S mutant expressed in baculovirus preincubated for 30 mins followed by fluorescein-LRRKtide substrate addition after 2 hrs by TR-FRET assay
Inhibition of recombinant human wild type GST-tagged LRRK2 (970 to 2527 residues) preincubated for 30 mins followed by fluorescein-LRRKtide substrate addition after 2 hrs by TR-FRET assay