Factor XI (HRP)

Factor XI (F.XI) is a coagulation protein produced in the liver that circulates in plasma at ~5ug/ml (30nM). The mass of F.XI is 160kD as determined by SDS-PAGE under non-reducing conditions and 80kD upon reduction. F.XI consists of two identical 80kD subunits linked by disulphide bonds. Each subunit consists of a tandem repeat of four apple domains followed by a serine protease catalytic domain. Cleavage of F.XI by activated factor XII or thrombin converts each subunit into a two-chain form and generates two active sites per F.XIa molecule. The mass of F.XIa is 160kD unreduced, but upon reduction F.XIa migrates as a heavy chain of 50kD and a light chain of 30kD. The catalytic site of F.XIa resides in the light chain. In plasma, F.XI or F.XIa circulates in non-covalent 1:1 complex with high molecular weight kininogen, which acts as a cofactor in the activation of F.XI by activated factor XII. The activity of F.XIa is regulated by platelets and by several proteinase inhibitors including, in order of decreasing importance, C1-inhibitor, a-2antiplasmin, a-1antitrypsin and antithrombin. Heparin has relatively little effect on the rate of inhibition of F.XIa by antithrombin. The only known natural substrate for activated F.XI (F.XIa) is factor IX (Christmas factor) and the only cofactor required for this reaction is ionized calcium (1-3).\n\nApplications:\nSuitable for use ELISA and Immunoelectrophoresis. Other applications not tested.\n\nRecommended Dilutions: \nOptimal dilutions to be determined by the researcher.\n\nRz Ratio (Reinheitszahl, A403/A280): 0.44\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Labeled with horseradish peroxidase (HRP). Sodium azide is a potent inhibitor of peroxidase and should not be added to HRP conjugates. HRP conjugates are sensitive to light.

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SPECIFICATIONS

Catalog Number

F0018-53B

Size

200ug

Applications

ELISA

Hosts

Goat

Reactivities

Hum

Form

Supplied as a liquid in a buffered stabilizer solution, 50% glycerol. Labeled with horseradish peroxidase (HRP).

P Type

Pab

Purity

Purified

Isotype

IgG

References

1. Wuillemin WA, Minnema M, Meijers JCM, Roem D, Erenberg AJM, Nuijens JH, ten Cate H, Hack EC; Inactivation of Factor XIa in Human Plasma Assessed by Measuring Factor XIa-Protease Inhibitor Complexes: Major Role for C1-Inhibitor. Blood 85:1517, 1995. 2. 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. 3. Baglia FA, Seaman FS, Walsh, PN; The Apple 1 and 4 domains of Factor XI Act to Synergistically Promote the Surface-Mediated Activation of Factor XI by Factor XIIa. Blood 85:2078, 1995.

Additional Info

Recognizes human Factor X1.