Native Human Factor B

• Cat.No.: CFB-104H

Specification

• Description: Complement factor B (fB) is purified from normal human serum. Complement factor B is a glycosylated protein composed of a single 93,000 Da polypeptide chain. It is an essential component of the alternative pathway of complement activation and is found in plasma at approximately 200 μg/mL. In the presence of Mg++ factor B binds to C3b and the C3b,B complex can be activated by factor D, a serine protease that circulates as an active trypsin-like serine protease. Cleavage of factor B by factor D causes the release of the Ba fragment (33,000 Da) and leaves the 60,000 Bb fragment bound to C3b. This Bb subunit is a serine protease. C3b,Bb is called a C3 and a C5 convertase because it converts both of these proteins to their active forms by cleaving off the small peptides C3a and C5a, respectively (Morikis, D. and Lambris, J.D. (2005); Morley, B.J. and Walport, M.J. (2000)).
• Source: Normal human serum (shown by certified tests to be negative for HBsAg, HTLV-I/II, STS and for antibodies to HCV, HIV-1 and HIV-II).
• Species: Human
• Form: Frozen liquid
• Molecular Mass: 93,000 Da (single chain)
• Purity: >95% by SDS-PAGE
• Characteristic: Molecular weight: 93,000 daltons, single chain protein containing 7.3-8.6% carbohydrate (Rother (1998)). The protein is negatively charged at serum pH and exhibits a heterogeneous pI = 5.6-6.1. Factor B is one of the heat labile proteins of the complement system. It binds divalent metal ions such as Mg++ or Ni++, which stabilize its interaction with C3b and C3b-like molecules. In the electron microscope factor B exhibits a three domain structure one domain of which is Ba. Bb contains two domains one of which is a von Willebrand factor-like A domain that binds to Mg++ and to C3b and the other, the C-terminal domain, contains the active serine protease site. The Ba domain actually contains of three SCR or CCP domains which interact with C3b. Crystal structures for the serine protease domain at 2.1 angstrom resolution (Jing, H. (2000)), the A domain (Milder, F.J. (2007)) and the whole protein (Bhattacharya, A.A. (2004)) at 2.3 A resolution have been published.
• Usage: For research use only. Not for human or drug use.
• Storage: -70°C or below. Avoid freeze/thaw.
• Concentration: 1.0 mg/mL (see Certificate of Analysis for actual concentration)
• Storage Buffer: 1.0 mg/mL (see Certificate of Analysis for actual concentration)
• Preservative: None, 0.22 μm filtered
• Warning: Use normal precautions for handling human blood products.
• Tag: Non

Gene Information

• Gene Name: CFB complement factor B [ Homo sapiens ]
• Official Symbol: CFB
• Synonyms: CFB; complement factor B; B factor, properdin , BF, BFD; H2 Bf; C3 proactivator; C3/C5 convertase; C3 proaccelerator; properdin factor B; B-factor, properdin; glycine-rich beta glycoprotein; glycine-rich beta-glycoprotein; BF; FB; BFD; GBG; CFAB; PBF2; AH
• Gene ID: 629
• mRNA Refseq: NM_001710
• Protein Refseq: NP_001701
• UniProt ID: P00751
• Chromosome Location: 6p21.3
• Pathway: Activation of C3 and C5, organism-specific biosystem; Alternative complement activation, organism-specific biosystem; Complement and coagulation cascades, organism-specific biosystem; Complement and coagulation cascades, conserved biosystem; Complement cascade, organism-specific biosystem; Immune System, organism-specific biosystem; Initial triggering of complement, organism-specific biosystem
• Function: complement binding; peptidase activity; serine-type endopeptidase activity