Bovine protein C inhibitor has a unique reactive site and can transiently inhibit plasmin

Citation
H. Yuasa et al., Bovine protein C inhibitor has a unique reactive site and can transiently inhibit plasmin, THROMB HAEM, 83(2), 2000, pp. 262-267
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
THROMBOSIS AND HAEMOSTASIS
ISSN journal
0340-6245 → ACNP
Volume
83
Issue
2
Year of publication
2000
Pages
262 - 267
Database
ISI
SICI code
0340-6245(200002)83:2<262:BPCIHA>2.0.ZU;2-G
Abstract
Protein C inhibitor (PCI) regulates the anticoagulant protein C pathway by neutralizing activated protein C and thrombin-thrombomodulin complex in the human hemostatic system. In this study, we cloned a full-length bovine PCI cDNA encoding a putative 19-residue signal peptide and a 385-residue matur e protein. this showed 70.6%. 70.6%, 57.5% and 59.6% amino acid sequence ho mology with the human, rhesus monkey, rat and mouse PCIs, respectively. Bov ine PCI mRNA (2.1 kb in size) was expressed strongly in the liver. and mode rately in the kidney and testis. but not in other tissues tested. Bovine PC I has a putative reactive site peptide bond, Lys-Ser, that is different fro m the reactive site sequence (Arg-Ser) of other species' PCI. We found that bovine PCI transiently inhibits bovine plasmin, but not human plasmin. Wes tern blot analysis showed that the reactive site of bovine PCI is cleaved d uring the course of complete formation with bovine plasmin: degraded PCI is released from the complex gradually concomitant with the recovery of plasm in activity. These findings suggest that bovine PCI plays a role not only i n the protein C pathway but also in the fibrinolytic activity of bovine hem ostatic system.