Abstract
Protease-activated receptors [PARs] are a family of G-protein-coupled seven-transmembrane domain receptors that are activated by proteolytic cleavage of their amino-terminal exodomain. To characterize the cleavage rate of human PAR-1 / 2 / 3 and 4 by trypsin and thrombin, four synthetic quenched-fluorescent peptide substrates have been synthesized. Each substrate consisted of a ten-residue peptide spanning the receptor activation cleavage site and using progress-curve kinetics, kcat / Km values were determined.
Keywords: Enzymology, serine proteases, progress-curve kinetics, fluorescence, 2-aminobenzoyl (Abz), 2,4-dinitrophenyl (Dnp), fluorescence resonance, G-protein-coupled, seven-transmembrane, domain receptor