Importance of the interaction between plasminogen and fibrin for plasminogen activation by tissue-type plasminogen activator.
The potentiating effect of fibrin monomer on plasminogen activation by tissue-type plasminogen activator is much more important with lys-plasminogen than with mini-plasminogen (which lacks the high affinity lysine-binding site important for binding to fibrin). Furthermore, this potentiating effect is totally abolished when lys-plasminogen is eluted from fibrin by the addition of 1 mM epsilon-amino caproic acid. Binding does however not seem to be the only condition required since it was found that fragment D is a much stronger potentiator of the activation of plasminogen by tissue-type plasminogen activator than fragment E although plasminogen binds to both fragment D and fragment E. Furthermore, fragment E has the same effect on the activation of lys-and mini-plasminogen by tissue-type plasminogen activator. Therefore, it is suggested that binding of plasminogen to fibrin involves a conformational change in the plasminogen molecule, facilitating its activation by tissue-type plasminogen activator.
D015119:Aminocaproic Acid / Q000494:pharmacology; D001665:Binding Sites; D005337:Fibrin / Q000378:metabolism*; D005342:Fibrinolysis; D006801:Humans; D010446:Peptide Fragments / Q000378:metabolism; D010958:Plasminogen / Q000378:metabolism*; D010960:Plasminogen Activators / Q000378:metabolism*
D010446:Peptide Fragments; C018998:lysyl-plasminogen; C044190:miniplasminogen; D005337:Fibrin; D010958:Plasminogen; D010960:Plasminogen Activators; D015119:Aminocaproic Acid