Fibrinogen C-terminal peptidic sequences (Haptides) modulate fibrin polymerization.

Citation:

Marx G, Ben-Moshe M, Magdassi S, Gorodetsky R. Fibrinogen C-terminal peptidic sequences (Haptides) modulate fibrin polymerization. Thromb. HaemostasisThrombosis and Haemostasis. 2004;91 (1) :43 - 51.

Date Published:

2004///

Abstract:

We previously described synthetic peptides of 19-21 amino acid residues, homologous to the C-termini of fibrinogen Fib340 and Fib420, from the β-chain (Cβ), the extended αE chain (CαE) and near the end of the γ-chain (preCγ) which elicited attachment (haptotactic) responses from mesenchymal cells. We named these haptotactic peptides -Haptides. The effects of Haptides on fibrin clot formation was evaluated and their possible effects on platelet aggregation was examd. The Haptides Cβ, CαE and preCγ, (2-10 μM) increased fibrin clot turbidity and also decreased thrombin-induced clotting time. Higher concns. (>120 μM of Cβ or preCγ) induced fibrinogen pptn. even without thrombin. These ppts. exhibited different ultrastructure from thrombin-induced fibrin by scanning and transmission microscopy. C-terminal peptides of the other fibrinogen chains exerted no such effects. Sepharose beads covalently coated with either whole fibrinogen or Haptides (SB-Fib or SB-Haptide) highly adsorbed free FITCHaptides. In aq. soln., Haptides formed nano-particles with av. size of ∼150nm in diam. We suggest that such pos. charged aggregates could serve to nucleate and accelerate fibrin gel formation. These results also indicate that Cβ and preCγ sequences within fibrin(ogen) participate in the docking and condensation of fibrin(ogen) during its assembly into a fibrin clot. By contrast, Haptides up to 100μM did not bind to platelets, and had no effect on platelet aggregation. Our findings highlight the roles of the C-terminal sequences of the β and γ chains in fibrin(ogen) polymn. as well as in cell attachment. [on SciFinder(R)]