CHEMBL5731358

FLIPR Assay: The activity of the PAR4 antagonists of the present invention were tested in PAR4 expressing cells by monitoring H-Ala-Phe(4-F)-Pro-Gly-Trp-Leu-Val-Lys-Asn-Gly-NH2-induced intracellular calcium mobilization using FDSS6000 (Hamamatsu Photonics, Japan) by fluo-4. Counter screens for agonist activity and PAR1 antagonist activity were also performed. Briefly, HEK293 EBNA PAR4 clone 20664.1J cells were plated 24 hrs. prior to experiment in 384 well, Poly-D-Lysine coated, black, clear bottom plates (Greiner Bio-One, Monroe, N.C.). Cells were plated at 20,000 cells/well in 20 μl growth medium and incubated at 37° C. with 5% CO2 overnight. At time of assay, media was replaced with 40 μl 1×Hank's Buffered Saline Solution (HBSS) (with 10 mM HEPES) and 20 μl test compound also diluted in 1×HBSS buffer was added at various concentrations and 0.67% DMSO final concentration on the FDSS for agonist measurement. The cells were then incubated for 30 minutes at room temperature followed by addition of 20 μl of agonist peptide for antagonist measurement on the FDSS. The agonist peptide H-Ala-Phe(4-F)-Pro-Gly-Trp-Leu-Val-Lys-Asn-Gly-NH2 for PAR4 antagonist screen or SFFLRR for PAR1 counter screen were routinely tested to ensure a response at EC50 in the assay (2.5 μM for H-Ala-Phe(4-F)-Pro-Gly-Trp-Leu-Val-Lys-Asn-Gly-NH2 and 600 nM for SFFLRR).