title: The incipient stage in thrombin-induced fibrin polymerization detected by FCS at the single molecule level.
abstract: We used fluorescence correlation spectroscopy (FCS) to study the activation of fibrinogen by thrombin and the subsequent aggregation of fibrin monomers into fibrin polymers at a very low and at physiological fibrinogen concentrations. In the labeling procedure used the fibrinogen was randomly labeled and the label was bound to the fibrinopeptide A and/or to the part of fibrinogen which after activation takes part in fibrin formation. We measured a diffusion coefficient for fibrinogen of 2.48 x 10(-7) +/- 0.10 x 10(-7) cm2/s. After activation with thrombin both fibrinopeptide A and fibrin polymerization products could be demonstrated. From our findings we suggest a model for the formation of a three-dimensional network as two parallel processes, elongation and branching and that fibrin oligomers are not only intermediates in the polymerization process but also are substrates for branching.
authors.affiliation: MBB, Karolinska Institute, Stockholm, S-171 77, Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Bark
authors.forename: Z
authors.initials: Z
authors.lastname: Földes-Papp
authors.forename: R
authors.initials: R
authors.lastname: Rigler
mesh_terms: D000465:Algorithms; D005337:Fibrin / Q000378:metabolism*; D008954:Models, Biological; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013917:Thrombin / Q000378:metabolism*; D013997:Time Factors
chemical_list: D005337:Fibrin; D013917:Thrombin