Abstract
Using the denatured chains of human fibrinogen as an immunogen and a unique screening procedure a mab (denoted mab A11 ) which reacts with fibrin and not with fibrinogen has been generated. While mab A11 does not react with intact soluble fibrinogen it reacts quite well with PVC immobilised fibrinogen or thrombin-treated fibrinogen. Immunoblotting of various plasmin-mediated SDS-PAGE separated fractions of the Aa-chain indicated that the epitope for A11 was near the carboxy terminal of the Aa-chain. Two distinct techniques, phage epitope display mapping and various Tenmer peptides comprising the Aa-chain of human fibrinogen indicated that the epitope resided in residues 551 -556 of the Aa. We have demonstrated that mab A11 and its Fab? derivative significantly enhance the thickness of fibrin fibres while the corresponding Fab fragment seems Io inhibit lateral polymerisation and thus generates thin fibrin fibres. This suggests that A11 may target a region of the Aa-chain involved in secondary or lateral polymerisation of fibrin. The specificity of this mab allowed a test for soluble fibrin (SF) to be constructed in conjunction with a specific mab which reacts with fibrin and not with fibrinogen (denoted 5F3). The assay for soluble fibrin was derived by binding plasma SF on the fibrin specific capture antibody (5F3) and tagging with a biotinylated AI l which was in turn monitored using horseradish peroxidase-labelled Streptavidin (HRP-S). Assay data from 2 large clinical stroke trials indicates the soluble fibrin (SF) levels vary greatly in the control aged population; however, while levels of control varied from 0-1000 u/ml the major group (-75%) contained 0-5 u/ml of SF. It is as yet not clear whether the control plasmas with high levels of SF (from 51000 units) reflect an in vivo or post sampling phenomenon. The incorporation of hirudin or hirudin/trasylol into the citrate anticoagulant did not seem to affect this data.
Original language | English |
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Article number | 68 |
Pages (from-to) | 25 |
Number of pages | 1 |
Journal | Fibrinolysis and Proteolysis |
Volume | 12 |
Issue number | SUPPL. 1 |
Publication status | Published - 1998 |
Externally published | Yes |