title: Immunovisualization of fibrinogen A alpha-chain heterogeneity in normal plasma and plasma from patients with DIC or on streptokinase therapy.
abstract: Purified fibrinogen as well as normal plasma, or plasma from patients with DIC or undergoing streptokinase(SK)-therapy was subjected to 1D- and 2D SDS-electrophoresis under reducing conditions. The pattern was revealed either by Coomassie-staining or immunostaining after Western-blotting and then compared. The use of polyclonal antibodies to fibrinogen as well as two monoclonal anti-bodies reacting with FPA and C-terminal part of the A alpha-chain confirmed immunologically the previously reported molecular weight heterogeneity of the A alpha-chain of the fibrinogen molecule as being a constituent of normal plasma, and lead to the following conclusions: 1. The MW-heterogeneity is observed in the fibrinogen pool of normal plasma as well as in DIC-plasma, SK-plasma and in purified fibrinogen, being the least noticeable in normal plasma and most advanced in SK-plasma. Patterns obtained using immunostaining with monoclonal anti-FPA confirm that the MW-heterogeneity of fibrinogen is mainly due to C-terminal degradation of the A alpha-chain. 2. Numerous A alpha-chain remnants (at least 9), with intact N-terminal ends, are found to be present in normal plasma, with a MW range from 66,200 to 36,000 Da, demonstrating that each of the "classical" HMW, LMW, LMW' subgroups consist of fibrinogen molecules which are very heterogeneous. 3. Two populations of A alpha-chains in purified fibrinogen and in fibrinogen in plasma react with the C-terminal specific Mab G-8. This is in contrast to the findings in plasma from streptokinase-treated patients, where several bands of lower molecular weights than the gamma-chain can be seen, suggesting the presence of free, circulating A-alpha chains split in the N-terminal half of the chain beyond the last inter-chain disulphide bond. 4. 2D electrophoresis disclosed substantial deviations in the patterns obtained with DIC-plasma, SK-plasma and with fibrinogen purified by beta-alanine-precipitation from that observed with normal plasma. The present technique allows selective characterization of fibrinogen independently of the other proteins present in plasma and offers extreme sensitivity.
authors.affiliation: Research Institute for Internal Medicine, University of Oslo, Rikshospitalet, Norway.
authors.forename: B
authors.initials: B
authors.lastname: Grøn
authors.forename: A
authors.initials: A
authors.lastname: Bennick
authors.forename: W
authors.initials: W
authors.lastname: Nieuwenhuizen
authors.forename: S
authors.initials: S
authors.lastname: Bjørnsen
authors.forename: F
authors.initials: F
authors.lastname: Brosstad
mesh_terms: D015153:Blotting, Western; D004211:Disseminated Intravascular Coagulation / Q000097:blood*; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000302:isolation & purification*; D005344:Fibrinopeptide A / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007120:Immunochemistry; D008970:Molecular Weight; D010446:Peptide Fragments / Q000276:immunology / Q000302:isolation & purification; D013300:Streptokinase / Q000494:pharmacology*
chemical_list: D010446:Peptide Fragments; D005344:Fibrinopeptide A; D005340:Fibrinogen; D013300:Streptokinase