Factor X Inhibitor Plasma
Factor X Inhibitor Plasma is manufactured from normal citrated human plasma depleted of Factor X using antibodies directed to FX immobilized on agarose beads. A polyclonal antibody inhibitory to FX has been added to provide FX neutralizing activity. The neutralizing antibody activity is determined by Nijmegen-modified Bethesda Inhibitor Assay and has values reported in Bethesda Units. Our Factor X Inhibitor Plasma is produced with three levels of inhibitor titre or neutralizing activity ranging from:
Mild Factor X Inhibitor (1-10 BU/mL)
Moderate Factor X Inhibitor (>10-50 BU/mL)
Strong Factor X Inhibitor (>50-200 BU/mL)
Frozen or Lyophilized formats available
Only the highest quality citrated plasma is used as starting material and in many cases the parent plasma is available as control material. Our Factor X Inhibitor Plasma can be used for further manufacturing or research use only applications.
Frozen Factor X Inhibitor Plasma
Product Code: INH10-DP
Presentation: Frozen Factor X Inhibitor 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 Factor X (FX)
Factor X (FX, Stuart Factor) is a vitamin K-dependent glycoprotein produced in the liver. The concentration of FX in plasma is ~10 μg/ml (~170 nM). Factor X is expressed as a two-chain molecule with a molecular weight of 59 kDa. The light chain (17 kDa) of FX contains a calcium-binding domain consisting of one hydroxy-aspartic acid and 11 γ-carboxyglutamic acid (gla) residues. These residues allow F.X to bind to membranes that contain acidic phospholipids in a calcium dependent manner. This is followed by two EGF-like domains. The heavy chain of FX (42 kDa) consists of the catalytic domain, carbohydrate and the activation peptide. Activation of FX to the active enzyme (FXa) results from cleavage at residue Arg52 in the heavy chain of F.X by a complex of F.IXa, cofactor VIIIa, calcium and negatively charged phospholipid surface (the tenase complex), or by the F.VIIa-tissue factor complex. Both activation pathways result in the release of the activation peptide from the N-terminal of the heavy chain. The FXa generated is a serine protease responsible for the activation of prothrombin to thrombin in the presence of a phospholipid membrane, calcium and cofactor Va. The activity of FXa in plasma is inhibited by antithrombin (ATIII), α1antitrypsin, α2macroglobulin and tissue factor pathway inhibitor (TFPI). The inhibitory activity of ATIII is stimulated approximately 1000-fold by heparin1-3.
1. Ichinose A, Davie EW; The Blood Coagulation Factors: Their cDNAs, Genes, and Expression; in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp 19-54, J.B. Lippincott Co., Philadelphia PA, USA, 1994.
2. Steinberg M, Nemerson Y; The Activation of Factor X; in Hemostasis and Thrombosis, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp 91-99, J.B. Lippincott Co., Philadelphia PA, USA, 1982.
3. Ellis V, Scully M, MacGregor I, Kakkar V; Inhibition of Human Factor Xa by Various Plasma Protease Inhibitors; Biochimica et Biophysica Acta 701, pp 24-31, 1982.