Individuals with elevated prothrombin levels are at increased risk of venous thrombosis. To understand the mechanism behind this observation, we studied the effect of prothrombin concentration on thrombin generation and fibrin clot structure. The pattern of thrombin generation was directly related to the prothrombin level at all concentrations tested. From 0 to 300% of normal plasma levels of p...

Prothrombin contains two kringle domains that are removed during activation to the blood clotting enzyme alpha-thrombin. By analogy with other kringle-containing proteins the prothrombin kringles may play a role in the protein-protein interactions necessary for prothrombin activation. Four monoclonal antibodies to prothrombin kringle 2 have been produced against human prothrombin, and a fifth m...

Individuals with elevated prothrombin levels are at increased risk of venous thrombosis. To understand the mechanism behind this observation, we studied the effect of prothrombin concentration on thrombin generation and fibrin clot structure. The pattern of thrombin generation was directly related to the prothrombin level at all concentrations tested. From 0% to 300% of normal plasma levels of ...

Background: Factor V Leiden, Prothrombin gene (G20210A) and MTHFR (C677T) polymorphism are the main biomarkers for evaluation of tendency for venous thromboembolism. We aimed to investigate the frequency of mutations in factor V Leiden, Prothrombin G20210A and MTHFR C677T and identify the genetic status for these mutations in patients with venous thrombosis. Methods: This study was carried out...

OBJECTIVE Two different prothrombin variants, p.Arg596Leu and p.Arg596Gln, conferring antithrombin resistance to patients with venous thromboembolism have been recently reported. Here, we describe a novel substitution affecting Arg596 of prothrombin molecule (Arginine596 to Tryptophan or p.Arg596Trp or Arg221aTrp in the chymotrypsinogen numbering system or prothrombin Padua 2) in 2 Italian fami...

The conversion of plasma to serum results in a variable loss of the coagulase-reacting factor (C.R.F.) of the plasma. The C.R.F. loss is incurred during the process of prothrombin conversion: conditions which favor the most effective prothrombin conversion result in maximal C.R.F. loss, while factors which interfere with prothrombin conversion spare the C.R.F. In a system containing an adequate...

The mechanisms by which blood levels of prothrombin (PT) are regulated in the vitamin K-sufficient state are unknown. We have studied PT synthesis by Reuber H-35 rat hepatoma cells exposed to vitamin K and [3H]leucine in serum-free cultures. Administration to the culture system of exogenous bovine PT and rat PT was characterized by increases in endogenous PT synthesis and secretion of 2- and 3-...