This proposal addrsses the structure-function relationship of the vitamin k-dependent blood coagulation proteins, with special attention to gamma carboxyglutamic acid. This program, which involves four separate but related projects, has evolved from previous work developed in the previous period. In Project #1, the structure-function relationship of Factor IX and prothrombin will be studied. Mutant forms of these proteins, obtained from patients with hereditary structural and functional abnormalities of these proteins, will be purified using conformation-specific antibodies, fragmented by proteolysis, and the mutant peptides sequenced. The molecular defect in each mutant protein will be established and correlated to functional defects. In Project #2, the newly discovered KC4 platelet membrane protein will be fully characterized and localized to specific subcellular organelles. The function and binding properties of this protein, expressed only on activated platelets, will be determined. Project #3 will define the role of Gla in prothrombin. A new model of Gla, metal, and membrane interaction in prothrombin using immunochemical and spectroscopic approaches will be evaluated. The membrane binding properties and Gla distribution of a series of partially carboxylated prothrombins should give insight into this problem. Project #4 is a direct clinical application of our immunochemical studies. Using antibodies specific for the fully carboxylated prothrombin (NPT) and des-gamma-carboxyprothrombin (APT), we will continue a clinical trial to evaluate these assays as an improved method of monitoring oral anticoagulant therapy. Vitamin K deficiency in newborns and their mothers will be studied, with the hope of developing simple rational approaches to eliminating hemorrhagic disease of the newborn. Furthermore, assay of the KC4 antigen, specific for activated platelets, will be explored as a method of detection of the prethrombotic state. These basic and clinical projects should make contributions to the understanding of this group of proteins, provide new modalities for the diagnosis of the prethrombotic state and vitamin K dificiency, and develop further data to justify the use of the NPT assay over the prothrombin time significantly reduce the morbidity/mortality associated with oral anticoagulation therapy.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Tufts University
United States
Zip Code
Furie, B; Diuguid, C F; Jacobs, M et al. (1990) Randomized prospective trial comparing the native prothrombin antigen with the prothrombin time for monitoring oral anticoagulant therapy. Blood 75:344-9
Gilbert, G E; Furie, B C; Furie, B (1990) Binding of human factor VIII to phospholipid vesicles. J Biol Chem 265:815-22
Ware, J; Diuguid, D L; Liebman, H A et al. (1989) Factor IX San Dimas. Substitution of glutamine for Arg-4 in the propeptide leads to incomplete gamma-carboxylation and altered phospholipid binding properties. J Biol Chem 264:11401-6
Diuguid, D L; Rabiet, M J; Furie, B C et al. (1989) Molecular defects of factor IX Chicago-2 (Arg 145----His) and prothrombin Madrid (Arg 271----cys): arginine mutations that preclude zymogen activation. Blood 74:193-200
Palabrica, T M; Furie, B C; Konstam, M A et al. (1989) Thrombus imaging in a primate model with antibodies specific for an external membrane protein of activated platelets. Proc Natl Acad Sci U S A 86:1036-40
Yeo, E; Furie, B C; Furie, B (1989) PADGEM protein in human erythroleukemia cells. Blood 73:722-8
Furie, B; Furie, B C (1988) The molecular basis of blood coagulation. Cell 53:505-18
Ulrich, M M; Furie, B; Jacobs, M R et al. (1988) Vitamin K-dependent carboxylation. A synthetic peptide based upon the gamma-carboxylation recognition site sequence of the prothrombin propeptide is an active substrate for the carboxylase in vitro. J Biol Chem 263:9697-702
Liebman, H A; Furie, B C; Furie, B (1987) The factor IX phospholipid-binding site is required for calcium-dependent activation of factor IX by factor XIa. J Biol Chem 262:7605-12
Jorgensen, M J; Cantor, A B; Furie, B C et al. (1987) Recognition site directing vitamin K-dependent gamma-carboxylation resides on the propeptide of factor IX. Cell 48:185-91

Showing the most recent 10 out of 24 publications