Ofosu F A, Freedman J, Dewar L, Song Y, Fenton J W
Canadian Red Cross Society, Blood Services, Hamilton, Ontario, L8N 1H8 Canada and McMaster University, Department of Pathology, HSC 3N26, 1200 Main St. West, Hamilton, Ontario, L8N 3Z5 Canada.
Biochem J. 1998 Dec 1;336 ( Pt 2)(Pt 2):283-5. doi: 10.1042/bj3360283.
Protease-activated receptor-1 (PAR-1) is a G-protein-linked receptor on platelets and perivascular cells activated by alpha-thrombin and the PAR-1-activating peptide, SFLLRN. alpha-Thrombin activates PAR-1 by cleaving it at R41-S42 to release the 41-residue peptide TR(1-41). Unexpectedly, platelet activation with SFLLRN was also associated with PAR-1 cleavage and the release of TR(1-41). Both PAR-1 cleavage and platelet activation resulting from SFLLRN addition to platelets were markedly inhibited by the serine protease inhibitor 4, 2-(aminoethyl)-benzene sulphonylfluoride.HCl (pefabloc SC) and soybean trypsin inhibitor, but not by inhibitors of calpain, cysteine proteases or metalloproteases. Thus, a trypsin-like platelet protease propagates SFLLRN-dependent PAR-1 cleavage and platelet activation.
蛋白酶激活受体-1（PAR-1）是血小板和血管周围细胞上的一种G蛋白偶联受体，可被α-凝血酶和PAR-1激活肽SFLLRN激活。α-凝血酶通过在R41-S42处切割PAR-1来激活它，从而释放41个氨基酸残基的肽TR(1-41)。出乎意料的是，用SFLLRN激活血小板也与PAR-1的切割和TR(1-41)的释放有关。向血小板中添加SFLLRN所导致的PAR-1切割和血小板激活均被丝氨酸蛋白酶抑制剂4, 2-(氨乙基)-苯磺酰氟盐酸盐（pefabloc SC）和大豆胰蛋白酶抑制剂显著抑制，但不受钙蛋白酶、半胱氨酸蛋白酶或金属蛋白酶抑制剂的抑制。因此，一种类似胰蛋白酶的血小板蛋白酶介导了SFLLRN依赖的PAR-1切割和血小板激活。
