Prothrombin – Factor II Deficient Plasma
Prothrombin – Factor II Deficient Plasma is manufactured from normal citrated human plasma that has been depleted of Prothrombin – Factor II by selective affinity immuno-adsorption using antibodies directed towards Prothrombin – FII.
Only the highest quality citrated plasma is used as starting material and in many cases the parent plasma is available as control material. Plasma products are typically buffered with the addition of HEPES to 20mM final concentration and are available in 1ml vials to litre quantities. Our Prothrombin – Factor II Deficient Plasma can be used for further manufacturing or research use only applications.
Product Code: FII-DP
Presentation: Frozen Prothrombin – Factor II Deficient Plasma
Preparation/Handling: Thaw 1 ml vials in 37oC water bath for 5 minutes; for bulk volumes, thawing time will be dependent on bottle size.
Storage and Stability: Plasma is shipped frozen and should be stored below -60oC. Product is stable until date stated on vial label when stored at -60oC. Once thawed, plasma is stable for 4 hours at 2-8oC in original vial.
Certificate of Analysis: available upon request
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 alpha-1-antitrypsin ¹-³.
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.