Prothrombin (factor II, F.II) is a vitamin K-dependent glycoprotein produced in the liver. The concentration of prothrombin in plasma is ~100ug/ml (~1.4uM). Prothrombin is a single chain molecule with a molecular weight of 72kD. Prothrombin consists of a catalytic domain followed by two kringle structures and an aminoterminal domain containing 10 gamma-carboxy-glutamic acid (gla) residues. These gla residues allow prothrombin to bind to membranes that contain acidic phospholipids in a calcium dependent manner. The binding to membranes is required for effective presentation of prothrombin as a substrate for activation by the prothrombinase complex, which consists of activated factor X, activated cofactor V and calcium on phospholipid membrane. Activation by prothrombinase occurs by sequential cleavage after residue Arg320 then after Arg271 to produce the active protease a- thrombin (37kD) and the by-product prothrombin fragment 1.2 (35kD).
The product thrombin further cleaves prothrombin fragment 1.2 after residue Arg155 into individual prothrombin fragments 1 and 2. The activity of a-thrombin in plasma is inhibited primarily by antithrombin and the rate of inhibition is accelerated 1000-fold in the presence of optimal concentrations of heparin. Other physiological inhibitors of thrombin in the absence of heparin include a2macroglobulin and a1antitrypsin.
Quantity:Sufficient reagent for 5x96 well plates.
Kit Components:P9117A: Prothrombin IgG: 1x500ul (Yellow cap) Polyclonal sheep anti-human Prothrombin IgG. Suitable for use as coating antibody
Supplied as a liquid in 50% glycerol
P9117B: Prothrombin IgG (HRP): 1x500ul (Red cap) Polyclonal Sheep anti-human Prothrombin IgG (HRP). Suitable for use as for detection antibody. Supplied as a liquid in 50% glycerol. Labeled with peroxidase.
Storage and Stability:Store all components at -20°C. Stable for 6 months. For maximum recovery of product, centrifuge the original vial prior to removing the cap.
