Anti-Prothrombin (FITC)

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 N-terminal domain containing 10 g-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 byproduct 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 (1-3). Factor II also plays a role in maintaining vascular integrity during development and postnatal life. Mutations in Factor II leads to various forms of thrombosis and dysprothrombinemia. Applications: Suitable for use in FLISA. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and store at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer. FITC conjugates are sensitive to light.