Complement Factor B
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Complement factor B (CFB) is a protein that is part of the alternative complement pathway. This pathway is a defense system that helps keep an organism intact by inactivating pathogens, invading organisms, and modified tissue cells.
CFB is a single-chain polypeptide that is 93 kDa. It contains a serine protease (SP) domain. When activated, CFB provides the catalytic activity of the alternative pathway C3 and C5 convertases.
CFB is purified from normal human serum and is found in plasma at about 200 µg/mL. It is a 764 amino acid molecule, including a 25 amino acid leader peptide.
Inhibiting CFB prevents complement activation in sera from C3 glomerulopathy patients and the hemolysis of human PNH erythrocytes.
Other names for CFB include:
- C3/C5 convertase
- Glycine-rich beta glycoprotein (GBG)
- PBF2
- Properdin factor B
Small-molecule factor B inhibitor for the treatment of complement-mediated diseases