Oxidized low-density lipoprotein associates strongly with carboxy-terminal domain of tissue factor pathway inhibitor and reduces the catalytic activity of the protein.
Tissue factor pathway inhibitor (TFPI) is a physiological protease inhibitor of the extrinsic blood coagulation pathway. Previously we have shown that TFPI associates quite rapidly with oxidized low-density lipoprotein (ox-LDL), with a reduction of the inhibitory activity on factor X activation. In the present study, it was found, by means of agarose gel electrophoresis, that the pre-incubation of full-length rTFPI with heparin or the carboxy (C)-terminal part (peptide 240-265) of TFPI prevented the association with ox-LDL in a dose-dependent manner. When rTFPI lacking the C-terminal basic part of the molecule (rTFPI-C) was mixed with ox-LDL, only a small amount of rTFPI-C was shifted to the position of ox-LDL on electrophoresis. Further, ox-LDL did not reduce the activity of rTFPI-C. These results indicate that the C-terminal domain of TFPI molecule plays a predominant role in the binding to ox-LDL and the binding through the C-terminal part is essential for the ox-LDL-dependent reduction of the anticoagulant activity of TFPI.
Horie
Shuichi
S
Department of Clinical Biochemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Tsukui, Kanagawa, Japan. shorie-v@pharm.teikyo-u.ac.jp
Hiraishi
Sayuri
S
Hamuro
Tsutomu
T
Kamikubo
Yu-ichi
Y
Matsuda
Juzo
J
D000918:Antibody Specificity; D000925:Anticoagulants / Q000494:pharmacology; D000941:Antigens / Q000187:drug effects / Q000276:immunology; D001797:Blood Protein Electrophoresis; D004587:Electrophoresis, Agar Gel; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008074:Lipoproteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism
D000925:Anticoagulants; D000941:Antigens; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C051928:lipoprotein-associated coagulation inhibitor; C099252:oxidized low density lipoprotein; D006493:Heparin