341262

Factor B, Human

Factor B, Human, is a single-chain glycoprotein present in normal human serum that is cleaved during the activation of complement via the alternative pathway into two fragments of 30 and 63 kDa.

Properties

• Assay: ≥90% (SDS-PAGE)
• form: liquid
• manufacturer/tradename: Calbiochem^®
• storage condition: OK to freeze; avoid repeated freeze/thaw cycles
• impurities: IgG, IgA, IgM, C3, C4, Factor H, Factor I, or albumin, trace (Ouchterlony)
• shipped in: wet ice
• storage temp.: −70°C

Description

General description

Factor B, Human, is a single-chain glycoprotein present in normal human serum that is cleaved during the activation of complement via the alternative pathway into two fragments of 30 and 63 kDa.

Native factor B from human serum. Single-chain glycoprotein present in normal human serum at about 200 µg/ml. During activation of complement via the alternative pathway, Factor B is cleaved and thus activated by Factor D into two fragments of M.W. of 30 kDa (Ba) and 63 kDa (Bb). The Bb fragment contains the serine protease enzymatic active site. The activated Bb fragment continues activation via the alternative pathway by cleaving, and thus activating, C3 and C5.

Native factor B from human serum. Single-chain glycoprotein present in normal human serum at about 200 µg/ml. During activation of complement via the alternative pathway, Factor B is cleaved, and thus activated by Factor D into two fragments of M.W. of ~30 kDa (Ba) and ~63 kDa (Bb). The Bb fragment contains the serine protease enzymatic active site. The activated Bb fragment continues activation via the alternative pathway by cleaving, and thus activating, C3 and C5.

Biochem/physiol Actions

≥1,200 Factor BH50 units/mg; ≥50% of Factor B activity in NHS (mg/mg basis)

Warning

Toxicity: Standard Handling (A)

Physical form

In PBS, pH 7.2.

Preparation Note

Prepared from serum that has been shown by certified tests to be negative for HBsAg and for antibodies to HIV and HCV.

Reconstitution

Following initial thaw, aliquot and freeze (-70°C).

Other Notes

Kam, C.M., et al. 1987. J. Biol. Chem. 262, 3444.
Gotze, O. and Muller-Eberhard, H.J. 1971. J. Exp. Med. 134, 90s.

Legal Information

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany