title: [Properties of 2 fibrin monomer species which differ in the degree of thrombin activation. Characteristics of successively appearing active sites].
abstract: Some properties of intermediate and final products of fibrinogen activation by thrombin have been studied. The intermediate (fB) lacks peptide A, the final fibrin (fo)--A and B peptides. Peculiar pH-dependent differences have been observed when examining the effect of ionic strength on polymerization rate of fo and fB. Intermolecular links present in fo polymer are found to be stronger than those of fB polymer. Curves of clot turbidity vs pH for fo and Fb do not coincide. Considering these results together with the literature data on the fibrin-polymer H-bond system one may assume that there are much more H-bonds in fo polymer than in its fB variant. Polymerization of fB has been found to be practically unaffected by higher NaCl concentrations which activate fo polymerization. Our and literature evidence lead to the conclusion that the active site (contact region), generated by the release of the peptide A, effects polymerization through electrostatic and H-bonding, whereas on the removal of the peptide B another active site arises of which a system of H-bonds and hydrophobic interactions are characteristic.
mesh_terms: D000818:Animals; D001665:Binding Sites; D001780:Blood Coagulation Tests; D002417:Cattle; D004789:Enzyme Activation; D005337:Fibrin / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D005344:Fibrinopeptide A / Q000378:metabolism; D005345:Fibrinopeptide B / Q000378:metabolism; D006860:Hydrogen Bonding; D046911:Macromolecular Substances; D013917:Thrombin / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D005344:Fibrinopeptide A; D005345:Fibrinopeptide B; D005337:Fibrin; D005340:Fibrinogen; D013917:Thrombin
vernacular_title: Svoĭstvadvukh form monomernogo fibrina, razlichaiushchikhsia po stepeni aktivatsii trombinom. Kharakteristika posledovatel'no obrazuiushchikhsia aktivnykh tsentrov.