The transport of alpha-fibrin monomer as a soluble complex with fibrinogen in the blood, and its rapid endocytic uptake serve as plasminogen-independent processes preventing the deposition of fibrin in the vasculature. Even before fibrin monomer is produced it is preceded by formation of substantial quantities of an intermediate, alpha-profibrin, lacking only one of the two A-fibrinopeptides that are cleaved in fibrin formation. Studies proposed here aim to secure the identification of this intermediate and extend our knowledge of its properties and role in hemostasis. Subsequent aims to clarify the chemical and biologic significance of alpha-profibrin address: 1) the equilibria and structural aspects of its interactions with itself and fibrinogen and fibrin; 2) the kinetics of its formation and transformation to fibrin; and 3) the clearance of alpha-profibrin from the circulation in vivo and uptake by cells in vitro. It is hypothesized that clearance of alpha-profibrin from blood safeguards against production of fibrin monomer, while elevations in plasma levels of alpha-profibrin serve as early harbingers of intravascular coagulation. The new separation methods also allow us to distinguish alpha-profibrin from the fibrinogen dimers in blood, arising from direct crosslinking by tissue transglutaminase in atherosclerotic aortic intima. Thus, virtually all of the principal derivatives of fibrinogen occurring in blood of normal subjects and subjects with vascular disease can be profiled for assessing transitions from prethrombotic to hypercoagulable states, and from early stages of atherosclerosis to its end stages predisposing thrombosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL060896-03
Application #
6081449
Study Section
Hematology Subcommittee 2 (HEM)
Project Start
1998-08-01
Project End
2001-06-30
Budget Start
1999-07-01
Budget End
2000-06-30
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Cleveland State University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
City
Cleveland
State
OH
Country
United States
Zip Code
44115
Smejkal, Gary B; Shainoff, John R; Kottke-Marchant, Kandice M (2003) Rapid high-resolution electrophoresis of multimeric von Willebrand Factor using a thermopiloted gel apparatus. Electrophoresis 24:582-7
Shainoff, John R; DiBello, Patricia M (2003) The circulatory half-lives of alpha-profibrin and alpha-fibrin monomer, and comparisons with other fibrin(ogen) derivatives. Thromb Haemost 89:48-52
Shainoff, John R; DiBello, Patricia M (2002) Fibrin precursors, intermediaries for hemostasis in the clot war. Thromb Res 105:3-13
Shainoff, John R; Smejkal, Gary B; DiBello, Patricia M et al. (2002) Allosteric effects potentiating the release of the second fibrinopeptide A from fibrinogen by thrombin. J Biol Chem 277:19367-73
Shainoff, J R; Ratnoff, O D; Smejkal, G B et al. (2001) Confirmation of mendelian properties of heterodimeric fibrinogen molecules in a heterozygotic dysfibrinogenemia, ""fibrinogen Amarillo,"" using gprphoresis to differentiate semifibrin molecules from fibrinogen and fibrin. Thromb Res 101:91-9
Shainoff, J R; Smejkal, G B; Dibello, P M et al. (2001) The fibrin intermediate, its place in the fibrinogen-fibrin transformation. Ann N Y Acad Sci 936:147-66