Activation/inactivation of human factor V by plasmin.
The effect of human plasmin on human coagulation factor V was studied using isolated proteins. Incubation of factor V with plasmin resulted in a rapid increase in procoagulant activity, followed by a subsequent decline in the ability of factor V to serve as a cofactor in the prothrombinase complex. Identical results were obtained when these reactions were conducted in the presence of dansylarginine-N-(3-ethyl-1,5-pentanediyl) amide (DAPA), indicating that the changes observed could not have occurred as a consequence of cleavage by alpha-thrombin. Analysis of the products of the reaction by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed a temporal correlation between the rise and fall in factor V activity and the presence of several transient intermediates. These fragments are distinct from the subunits of alpha-thrombin-activated factor V (factor Va). The activation phase of the reaction was not significantly affected by the presence of phospholipid. In contrast, the rate of degradation of active fragments of factor V and the accompanying loss of activity were markedly enhanced in the presence of phospholipid vesicles. These data suggest that the action of plasmin upon factor V results in the transient formation of proteolytic fragments which express significant procoagulant activity.
Lee
C D
CD
Department of Biochemistry, University of Vermont, College of Medicine, Burlington 05405-0068.
Mann
K G
KG
D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001780:Blood Coagulation Tests; D003619:Dansyl Compounds / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005165:Factor V / Q000302:isolation & purification / Q000378:metabolism*; D015943:Factor Va; D005341:Fibrinolysin / Q000494:pharmacology*; D006801:Humans; D008970:Molecular Weight; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D010958:Plasminogen; D013379:Substrate Specificity; D013917:Thrombin / Q000037:antagonists & inhibitors
D003619:Dansyl Compounds; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; C019162:dansylarginine N-(3-ethyl-1,5-pentanediyl)amide; D015943:Factor Va; D005165:Factor V; D010958:Plasminogen; D001120:Arginine; D013917:Thrombin; D005341:Fibrinolysin