JF5 (PAR1 inhibitor JF5) is an allosteric inhibitor of PAR1 that binds to helix 8 of the receptor; inhibits PAR1 coupling to Gα subunits, but fails to inhibit signaling downstream of Gα12/13.
JF5 also interacts with the α2A-adrenergic receptor.
JF5 blocks granule secretion from platelets activated with the PAR1 agonist SFLLRN with IC50 of 4 uM, inhibits AYPGKF-mediated activation of murine platelets with IC50 of 10 uM.
JF5 inhibited thrombus formation in vivo following vascular injury with IC50 of 1 mg/kg.
JF5 is a useful probe to evaluate the role of H8 in coupling of GPCRs to cognate Gα subunits.
