Antibodies to Factor IX

Factor IX, human

Antibody Host Catalogue No. Size Product Insert
Purified IgG Goat GAFIX-IG 10 mg
Affinity purified IgG Goat GAFIX-AP 0.5 mg
Peroxidase conjugated IgG Goat GAFIX-HRP 0.2 mg
Affinity purified, peroxidase conj. IgG Goat GAFIX-APHRP 0.1 mg
Affinity purified, FITC conjugated IgG Goat GAFIX-APFTC 0.1 mg
Affinity purified, biotinylated IgG Goat GAFIX-APBIO 0.1 mg
Purified IgG Sheep SAFIX-IG 10 mg
Affinity purified IgG Sheep SAFIX-AP 0.5 mg
Affinity purified, peroxidase conj. IgG Sheep SAFIX-APHRP 0.1 mg
Matched Pair Antibodies for EIA FIX-EIA 5 plates

Factor IX, canine

Antibody Host Catalogue No. Size Product Insert
Matched Pair Antibodies for EIA CFIX-EIA 4 plates

Description of Factor IX F9

Factor IX (FIX, Christmas Factor) is a vitamin K-dependent glycoprotein produced in the liver. Plasma concentration of FIX is normally around 5 μg/ml (87 nM) in plasma. The biological importance of FIX is demonstrated in Haemophilia B (Christmas disease), an X-linked congenital bleeding disease resulting from a quantitative (low activity and low antigen) or qualitative (low activity, normal antigen) defect in FIX function.

In its proenzyme or zymogen form FIX is a single chain molecule of 55,000 daltons. It contains two EGF-like domains and an amino-terminal domain containing 12 γ-carboxy-glutamic acid (Gla) residues. These Gla residues allow FIX to bind divalent metal ions and participate in calcium-dependent binding interactions. The activation of F.IX occurs by limited proteolysis in the presence of calcium by activated factor XI (FXIa) and/or by a complex of VIIa/tissue factor/phospholipid and activated Factor X between residues Arg146-Ala147 and between Arg180-Val181. The terminal activated product in either case is FIXaβ, a two-chain enzyme consisting of a heavy chain (28,000 daltons), a light chain (18,000 daltons) and an activation peptide product of 11,000 daltons. FIX can also be cleaved into inactive products by thrombin and by elastase.

The activity of FIXaβ in plasma is inhibited by antithrombin and this inhibition is accelerated 1000-fold in the presence of optimal concentrations of heparin 1-3.

References and Reviews
  1. Lawson, JH, Mann KG; Cooperative Activation of Human F.IX by the Human Extrinsic Pathway of Coagulation; JBC 266 pp11317-11327, 10991.
  2. Enfield DL, Thompson AR; Cleavage and Activation of Factor IX by Serine Proteases; Blood 64, pp 821-831, 1984.
  3. Limentani SA, Furie BC, Furie B, in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 94-108, J.B. Lippincott Co., Philadelphia PA, USA, 1994