Fibrinogen alpha C domains contain cryptic plasminogen and tPA binding sites.
Surface plasmon resonance and ELISA experiments revealed that recombinant fibrinogen alpha C fragment (residues A alpha 221-610) corresponding to the alpha C domain binds tPA and plasminogen with high affinity. This binding was found to be Lys-dependent and occurred via independent binding sites. Study with truncated variants of the alpha C fragment located these sites in its COOH-terminal half. Binding of tPA and plasminogen to these sites stimulated activation of the latter whereas proteolytic degradation of the alpha C fragment reduced this effect substantially, suggesting the importance of the alpha C domains in regulation of fibrinolysis.
Tsurupa
G
G
Biochemistry Department, Holland Laboratory, American Red Cross, 15601 Crabbs Branch Way, Rockville, MD 20855, USA. tsiouriog@usa.redcross.org
Medved
L
L
D001665:Binding Sites; D005340:Fibrinogen / Q000737:chemistry / Q000378:metabolism*; D010958:Plasminogen / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D005340:Fibrinogen; D010958:Plasminogen; D010959:Tissue Plasminogen Activator