The long term objective of the proposed study is to obtain a better understanding of blood coagulation mechanisms by identification of the molecular defects in four different human dysfibrinogens, and application of this information to the study of functional domains in normal human fibrinogen. Since these four dysfibrinogens exhibit different abnormal functional characteristics, the molecular defects will also be different. Thus, from four perspectives we have the opportunity to provide new knowledge regarding (a) functionally important domains in fibrinogen (b) mechanisms of fibrinopeptide release and fibrin monomer polymerization, (c) fibrinogen ultrastructure and (d) biologic activity of fibrinogen fragments.
The specific aims of the proposed study are: (1) to completely characterize the functional defects of four dysfibrinogens; (2) to identify the molecular defects responsible for the abnormal coagulation behavior of four dysfibrinogens; (3) to use peptides containing the molecular defects as probes for study of coagulation mechanisms including fibrinopeptide release, fibrin monomer polymerization, calcium binding fibrin ligation, fibrinogen ultrastructure, and biological activity of fibrinogen fragments. The methodology required to accomplish these goals will include standard clinical assays and standard analytical techniques. A novel, systematic approach to the production, HPLC analysis, and isolation of protease-derived fibrinogen fragments has been developed and will be employed. The health relatedness of this proposal stems primarily from the possibility that fragments or peptides containing the molecular defect may exhibit anticoagulant activity. The information derived from studying the behavior of these altered molecular probes will ultimately have therapeutic applications. Moreover, the identification of loci in which single amino acid substitutions produce functional defects will elucidate the role that portion of the molecule plays in coagulation, produce a greater understanding of the structural domains in fibrinogen, and thereby permit a rational approach to treatment of fibrinogen-related coagulopathies.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Unknown (R23)
Project #
5R23HL029067-03
Application #
3448476
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1983-12-01
Project End
1986-11-30
Budget Start
1985-12-01
Budget End
1986-11-30
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Lankiewicz, M W; Bell, W R (1992) A unique circulating inhibitor with specificity for coagulation factor X. Am J Med 93:343-6
Schmelzer, C H; Ebert, R F; Bell, W R (1989) Fibrinogen Baltimore IV: congenital dysfibrinogenemia with a gamma 275 (Arg----Cys) substitution. Thromb Res 56:307-16
Ebert, R F; Bell, W R (1988) Fibrinogen Baltimore III: congenital dysfibrinogenemia with a shortened gamma-subunit. Thromb Res 51:251-8
Schmelzer, C H; Ebert, R F; Bell, W R (1988) A polymorphism at B beta 448 of fibrinogen identified during structural studies of fibrinogen Baltimore II. Thromb Res 52:173-7
Ebert, R F; Schmelzer, C H (1988) Isolation and comparative peptide mapping of fibrinogen subunits by reversed-phase high-performance liquid chromatography. J Chromatogr 443:309-16
Ebert, R F; Schreiler, W E; Bell, W R (1986) Fibrinogen Seattle II: congenital dysfibrinogenemia with an Arg (A alpha 16)----his substitution. Thromb Res 43:7-13
Kaiser, D A; Sato, M; Ebert, R F et al. (1986) Purification and characterization of two isoforms of Acanthamoeba profilin. J Cell Biol 102:221-6
Ebert, R F (1986) Amino acid analysis by HPLC: optimized conditions for chromatography of phenylthiocarbamyl derivatives. Anal Biochem 154:431-5
Dang, C V; Ebert, R F; Bell, W R (1985) Localization of a fibrinogen calcium binding site between gamma-subunit positions 311 and 336 by terbium fluorescence. J Biol Chem 260:9713-9
Ebert, R F; Bell, W R (1985) Assay of human fibrinopeptides by high-performance liquid chromatography. Anal Biochem 148:70-8

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