Fibronectin fibrin

Collagens I, II, III, VII, VIII, X, XI, gelatins, aggrecan, fibronectin, fibrin, fibronogen, entactin, laminin, tenascin, vitronectin... 

Figure 48-3. Schematic representation of fibronectin. Seven functional domains of fibronectin are represented two different types of domain for heparin, cell-binding, and fibrin are shown. The domains are composed of various combinations of three structural motifs (I, II, and III), not depicted in the figure. Also not shown is the fact that fibronectin is a dimer joined by disulfide bridges near the carboxyl terminals of the monomers. The approximate location of the RGD sequence of fibronectin, which interacts with a variety of fibronectin integrin receptors on cell surfaces, is indicated by the arrow. (Redrawn after Yamada KM Adhesive recognition sequences.

Fibronectins are typical representatives of adhesive proteins. They are filamentous dimers consisting of two related peptide chains (each with a mass of 250 kDa) linked to each other by disulfide bonds. The fibronectin molecules are divided into different domains, which bind to cell-surface receptors, collagens, fibrin, and various proteoglycans. This is what gives fibronectins their molecular glue" characteristics. 

Berman, M., Manseau, E., Law, M., Aiken, D. Ulceration is correlated with degradation of fibrin and fibronectin at the corneal surface. Invest Ophthalmol Vis Sci 24, 1358-1366 (1983)... 

Many isopeptide bonds can be formed between the side chains of e-lysine (donor) and 7-glutamine (acceptor) residues (Fig. 8). The 7 chains of fibrinogen are crosslinked or ligated first, followed by the C-terminal a chains. In addition, other proteins—notably n2-antiplasmin, plasminogen activator inhibitor-2, and fibronectin—are also covalently ligated to fibrin by Factor XHIa (Greenberg et al, 2003). 

Some proteins, such as plasma fibronectin and albumin, interact with fibrin to alter clot structure and properties, although the former becomes crosslinked to fibrin while the latter does not. As a result of these and other interactions, fibrin clots formed in plasma have very different properties than those made with purified proteins (Blomback et al, 1994 Carr, 1988 Shah et al., 1987). Albumin has significant effects on the extent of lateral aggregation, yielding either thicker or thinner fibers depending on its concentration and other experimental conditions (Galanakis et al, 1987 Torbet, 1986). 

Makogonenko, E., Tsurupa, G., Ingham, K., and Medved, L. (2002). Interaction of fibrin (ogen) with fibronectin Further characterization and localization of the fibronectin-binding site. Biochem. 41, 7907-7913. 

Fig. 5-25 Diagrammatic representation of the domains of fibronectin Domain A binds to heparin and fibrin.

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