PAR4 (1-6) is a peptide agonist of proteinase-activated receptor 4 (PAR4) that corresponds to residues 1-6 of the amino terminal tethered ligand sequence of human PAR4 and residues 48-53 of the full-length sequence.[1] It activates PAR4 and the cleavage site mutant PAR4R47A when used at a concentration of 500 µM.[2] PAR4 (1-6) induces platelet aggregation of isolated washed human platelets when used at a concentration of 1 mM but does not affect clotting time induced by factor VIIa, soluble tissue factor, and collagen in an ex vivo coagulation assay.[3]
References:
[1]. Vergnolle, N., Wallace, J.L., Bunnett, N.W., et al. Protease-activated receptors in inflammation, neuronal signaling and pain. Trends Pharmacol. Sci. 22(3), 146-152 (2001).
[2]. Xu, W.F., Andersen, H., Whitmore, T.E., et al. Cloning and characterization of human protease-activated receptor 4. Proc. Natl. Acad. Sci. USA 95(12), 6642-6646 (1998).
[3]. Andersen, H., Greenberg, D.L., Fujikawa, K., et al. Protease-activated receptor 1 is the primary mediator of thrombin-stimulated platelet procoagulant activity. Proc. Natl. Acad. Sci. USA 96(20), 11189-11193 (1999).