Activation of Bovine Factor V by Thrombin and A Protease From Russell's Viper Venom (RVV)

1979 ◽  
Author(s):  
M.J. Lindhout ◽  
C. M. Jackson

In order to understand the function of activated factor V in the prothrombinase complex, we isolated the activation products obtained by action of thrombin and RVV-V on factor V and studied their functional properties. Factor V isolated from plasma by means of ion-exchange chromatography, a Ca-oxalate adsorption step and gelfiltration was homogenous in SDS-gelelectrophoresis (apparent MW 360,000, with and without reduction). Increase in factor V activity upon action by RVV-V is correlated with a single peptide bond cleavage, resulting in a 270,000 dalton and a 80,000 dalton component. Additional proteolysis of factor Va(RVV/V)’ by thrombin results in a further cleavage of the high MW component into peptides with MW's of 72,000, 94,000 and about 150,000 without a furth~r increase in factor V activity. Whereas none of the isolated peptides reveal factor Va activity, activity would be generated by a recombination in the presence of Ca2+ of the 94,000 MW or 270,000 MW component with the 80,000 component. Action of thrombin alone on factor V results in peptides of MW 72,000, 80,000, 94,000 and a peptide very rich in carbohydrate with an apparent MW of 150,000.

2004 ◽  
Vol 279 (19) ◽  
pp. 19580-19591 ◽  
Author(s):  
Thomas Orfeo ◽  
Nicole Brufatto ◽  
Michael E. Nesheim ◽  
Hung Xu ◽  
Saulius Butenas ◽  
...  

The prothrombinase complex consists of the protease factor Xa, Ca2+, and factor Va assembled on an anionic membrane. Factor Va functions both as a receptor for factor Xa and a positive effector of factor Xa catalytic efficiency and thus is key to efficient conversion of prothrombin to thrombin. The activation of the procofactor, factor V, to factor Va is an essential reaction that occurs early in the process of tissue factor-initiated blood coagulation; however, the catalytic sequence leading to formation of factor Va is a subject of disagreement. We have used biophysical and biochemical approaches to establish the second order rate constants and reaction pathways for the activation of phospholipid-bound human factor V by native and recombinant thrombin and meizothrombin, by mixtures of prothrombin activation products, and by factor Xa. We have also reassessed the activation of phospholipid-bound human prothrombin by factor Xa. Numerical simulations were performed incorporating the various pathways of factor V activation including the presence or absence of the pathway of factor V-independent prothrombin activation by factor Xa. Reaction pathways for factor V activation are similar for all thrombin forms. Empirical rate constants and the simulations are consistent with the following mechanism for factor Va formation. α-Thrombin, derived from factor Xa cleavage of phospholipid-bound prothrombin via the prethrombin 2 pathway, catalyzes the initial activation of factor V; generation of factor Va in a milieu already containing factor Xa enables prothrombinase formation with consequent meizothrombin formation; and meizothrombin functions as an amplifier of the process of factor V activation and thus has an important procoagulant role. Direct activation of factor V by factor Xa at physiologically relevant concentrations does not appear to be a significant contributor to factor Va formation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Riley B. Peacock ◽  
Taylor McGrann ◽  
Marco Tonelli ◽  
Elizabeth A. Komives

AbstractSerine proteases catalyze a multi-step covalent catalytic mechanism of peptide bond cleavage. It has long been assumed that serine proteases including thrombin carry-out catalysis without significant conformational rearrangement of their stable two-β-barrel structure. We present nuclear magnetic resonance (NMR) and hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments on the thrombin-thrombomodulin (TM) complex. Thrombin promotes procoagulative fibrinogen cleavage when fibrinogen engages both the anion binding exosite 1 (ABE1) and the active site. It is thought that TM promotes cleavage of protein C by engaging ABE1 in a similar manner as fibrinogen. Thus, the thrombin-TM complex may represent the catalytically active, ABE1-engaged thrombin. Compared to apo- and active site inhibited-thrombin, we show that thrombin-TM has reduced μs-ms dynamics in the substrate binding (S1) pocket consistent with its known acceleration of protein C binding. Thrombin-TM has increased μs-ms dynamics in a β-strand connecting the TM binding site to the catalytic aspartate. Finally, thrombin-TM had doublet peaks indicative of dynamics that are slow on the NMR timescale in residues along the interface between the two β-barrels. Such dynamics may be responsible for facilitating the N-terminal product release and water molecule entry that are required for hydrolysis of the acyl-enzyme intermediate.


Blood ◽  
1989 ◽  
Vol 73 (1) ◽  
pp. 185-190 ◽  
Author(s):  
CD Lee ◽  
KG Mann

Abstract 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.


2016 ◽  
Vol 133 ◽  
pp. S426-S431 ◽  
Author(s):  
Mikhail M. Vorob’ev ◽  
Claire I. Butré ◽  
Stefano Sforza ◽  
Peter A. Wierenga ◽  
Harry Gruppen

ChemInform ◽  
2010 ◽  
Vol 24 (28) ◽  
pp. no-no
Author(s):  
J. R. SPENCER ◽  
N. G. J. DELAET ◽  
A. TOY-PALMER ◽  
V. V. ANTONENKO ◽  
M. GOODMAN

1992 ◽  
Vol 11 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Chi-Yue Wu ◽  
Shui-Tein Chen ◽  
Shyh-Horng Chiou ◽  
Kung-Tsung Wang

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