Biopolym. Cell. 1997; 13(4):291-297.
Structure and Function of Biopolymers
Transmission electron microscopy study of co-polymers of fibrinogen with N-terminal disulfide knot of fibrin
1Pozdnjakova T. M., 1Chernishov V. I., 1Makogonenko E. M., 1Chernishenko T. M., 1Cederholm-Williams S. A.
  1. Palladin Institute of Biochemistry, NAS of Ukraine
    9, Leontovycha Str., Kyiv, Ukraine, 01601

Abstract

The structure of co-polymers of fibrinogen (F) with N-terminal disulfide knot of desAABB fibrin (tN-DSK) was investigated by transmission electron microscopy of their negatively contrasted samples. It was shown that the co-polymers initial forms were represented by short threads of 2–4 end-to-end arranged F molecules, in which tN-DSK molecules could't be visualized by the used method. Then long single-threaded structures formed which aggregated laterally in fibril-like bunches of varying thickness. The network of fibrils have arisen finally. In control experiments when in the fibrinogen containing samples tN-DSK was substituted for thrombin, one could observe the double-threaded twisted protofibrils but not any of the single-threaded end-to-end arranged molecules. These studies confirm the hypothetical model of F-tN-DSK co-polymer structure as the thread of end-to-end arranged fibrinogen molecules, the adjacent D-domain of which are bound by tN-DSK molecules via the fibrin polymerization sites. The lateral aggregation of co-polymer strains into fibrils and fibril network formation revealed in this study is the evidence of similarity between F-tN-DSK co-polymers and. fibrin polymer structures. It is not wonder because both structures are formed by the unique self-assembly mechanism in which the noncovalent binding of fibrin(ogen) molecules by the complementary fibrin polymerization sites is involved.

References

[1] Blomback B. Fibrinogen and fibrin formation. Plasma proteins. Eds B. Blomback, L. A. Hanson. New York: John Willey and Sons, 1979: 223-53.
[2] Pozdniakova TM, Rybachuk VN. [Complexes of the N-terminal disulfide branch point of fibrin with fibrinogen]. Ukr Biokhim Zh. 1985;57(1):3-8.
[3] Pozdniakova TM, Rybalchuk VN, Il'ina AV, Davidovich IuA, Rogozhin SV. [Effect of peptides--structural analogs of NH2-terminal sites of fibrin alpha- and beta-chains--on specific binding of the NH2-terminal disulfide bond of fibrin with fibrinogen]. Ukr Biokhim Zh. 1986;58(2):10-5.
[4] Pozdniakova TM, Rybachuk VN, Ugarova TP. [The role of D2-E2 centers of interdomain binding of fibrin monomer during fibrinogen co-polymerization with an NH2-terminal disulfide knot of fibrin]. Biokhimiia. 1987;52(4):592-8.
[5] Varetskaya TV. Microheterogenity of fibrinogen. Cryofibrinogen. Ukr Biokhim Zh. 1960; 32(1):13-24.
[6] Pozdnjakova TM, Musjalkovskaja AA, Ugarova TP, Protvin DD, Kotsjuruba VN. On the properties of fibrin monomer prepared from fibrin clot with acetic acid. Thromb Res. 1979;16(1-2):283-8.
[7] Pozdniakova TM, Rybachuk VN, Vovk EV. [Soluble complexes of the NH2-terminal disulfide knot of fibrin with molecules containing D domains]. Ukr Biokhim Zh. 1983;55(6):614-21.
[8] Williams RC. Morphology of bovine fibrinogen monomers and fibrin oligomers. J Mol Biol. 1981;150(3):399-408.