Factor XII, human

Antibody	Host	Catalogue No.	Size	Product Insert
Purified IgG	Goat	GAFXII-IG	5 mg
Affinity purified IgG	Goat	GAFXII-AP	0.5 mg
Peroxidase conjugated IgG	Goat	GAFXII-HRP	0.2 mg
Purified IgG	Sheep	SAFXII-IG	5 mg
Affinity purified IgG	Sheep	SAFXII-AP	0.5 mg
Matched Pair Antibodies for EIA		FXII-EIA	5 plates

Description of Factor XII (FXII)

Factor XII (FXII, Hageman factor) is a 76 kDa, single chain glycoprotein produced in the liver. In plasma, FXII circulates as a protease zymogen at a concentration of approximately 30 μg/ml (400 nM). Upon vascular injury FXII binds to negatively charged extravascular surfaces such as cartilage and skin, which facilitate activation of the zymogen to the active serine protease. Cleavage of F.XII by kallikrein after residue Arg353 produces the enzyme αFXIIa, consisting of a 28 kDa light chain containing the protease domain, and a 52 kDa heavy chain containing the anionic surface-binding domain. Substrates for surface bound FXIIa include the zymogens prekallikrein (PK) and factor XI (FXI) as well as the procofactor high-molecular weight kininogen (HK). The activation of these substrates results in positive feedback activation of FXII. Further cleavage of αFXIIa by kallikrein produces the 28 kDa fragment βFXIIa (Hageman factor fragment). βFXIIa has reduced procoagulant activity as it lacks the anionic surface-binding domain, but is capable of fluid-phase activation of PK, factor VII and complement C1. The activity of F.XIIa in plasma is regulated predominantly by C1-Inhibitor, with relatively minor contributions by α2antiplasmin, α2macroglobulin and antithrombin, even in the presence of therapeutic levels of heparin^1-3.

References:

1. DeLa Cadena R, Watchtfogel YT, Colman RW, in Hemostasis and Thrombosis, 3rd Edition, eds. RW Colman, J Hirsh, VJ Marder and EW Salzman, pp. 219-240, J.B. Lippincott Co., Philadelphia, 1994.

2. Tankersley DL, Alving BM, Finlayson JS; Preparation of βF.XIIa (Hageman Factor Fragment) from Human Plasma. Thrombosis Research 25 pp 307-317, 1982.

3. Pixley RA, Schapira M, Coleman RW; The regulation of Human Factor XIIa by Plasma Proteinase Inhibitors. JBC 260, pp 1723-1729, 1985.

Related Products:

GAFXII-IG Goat anti-human F.XII, whole IgG from antiserum

GAFXII-HRP Goat anti-human F.XII, IgG-peroxidase conjugate

SAFXII-IG Sheep anti-human F.XII, IgG from antiserum

SAFXII-AP Sheep anti-human F.XII, affinity purified IgG

FXII-EIA Paired antibody set for ELISA of F.XII, 5 x 96 wells

FXII-DP Human plasma deficient in Factor XII, immune depleted

INH12-DP Factor XII Inhibitor Plasma, Frozen

INH12-LDP Factor XII Inhibitor Plasma, Lyophilized