Prothrombin – Factor II Paired Antibody Set
Affinity’s Prothrombin – Factor II Paired Antibody Set consists of matched capture and detecting antibodies that have been titrated and optimized for use in sandwich style ELISA assays. The product as provided contains sufficient capture and detecting antibodies for five full 96-well microplates and contains a detailed protocol sheet containing directions for use, recipes for solutions and sources for additional materials required. This Prothrombin – Factor II Paired Antibody Set is intended to facilitate the end user in establishing an “in-house” immunoassay for research purposes only and must not be used for diagnostic applications. Assay validation is the responsibility of the end user.
Product Code: FII-EIA
- Capture Antibody (FII-EIA-C): One yellow-capped vial containing 0.5 ml of polyclonal affinity purified anti-Prothrombin antibody for coating plates.
- Detecting Antibody (FII-EIA-D): One red-capped tube containing 0.5 ml of peroxidase conjugated affinity-purified polyclonal anti-Prothrombin antibody for detection of captured Prothrombin – Factor II.
Species Cross Reactivity: View Chart
Description of Prothrombin – Factor II
Prothrombin (factor II, F.II) is a vitamin K-dependent glycoprotein produced in the liver. The concentration of prothrombin in plasma is ~100 μg/ml (~1.4 μM). Prothrombin is a single chain molecule with a molecular weight of 72 kDa. Prothrombin consists of a catalytic domain followed by two kringle structures and an amino-terminal domain containing 10 γ-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 α-thrombin (37 kDa) and the by-product prothrombin fragment 1.2 (35 kDa). The product thrombin further cleaves prothrombin fragment 1.2 after residue Arg155 into individual prothrombin fragments 1 and 2. The activity of α-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 α2macroglobulin and α1antitrypsin1-3.
References and Reviews
- Mann KG; Prothrombin and Thrombin; in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 184-199, J.B. Lippincott Co., Philadelphia PA, USA, 1994.
- Mann KG; Prothrombin; Methods in Enzymology 45, pp 123-156, 1976.
- Downing MW, Bloom JW, Mann KG; Comparison of the Inhibition of Thrombin by Three Plasma Protease Inhibitors; Biochemistry 17, pp 2649-2653, 1978.