CFB (26-259) Human

Complement Factor B is a single-chain polypeptide that circulates in the blood. It is cleaved by complement factor D into two fragments: Ba and Bb. The Bb fragment is a serine protease that combines with C3b to form the C3 convertase (C3bBb), which is essential for the amplification loop of the alternative pathway .

The specific fragment of Complement Factor B (26-259 a.a.) refers to the Ba fragment, which is involved in inhibiting the proliferation of preactivated B lymphocytes . This fragment is produced recombinantly in E. coli and consists of 257 amino acids with a molecular mass of approximately 28.4 kDa .

The recombinant Complement Factor B (26-259 a.a.) is produced in Escherichia coli (E. coli). It is fused to a 23 amino acid His-tag at the N-terminus, which facilitates its purification through chromatographic techniques . The final product is a sterile, filtered, colorless solution containing 20mM Tris-HCl buffer (pH 8.0), 10% glycerol, and 0.4M urea .

For optimal stability, the recombinant protein should be stored at 4°C if it will be used within 2-4 weeks. For longer storage periods, it should be frozen at -20°C. To prevent degradation, it is recommended to add a carrier protein (0.1% HSA or BSA) and avoid multiple freeze-thaw cycles .

Recombinant Complement Factor B (26-259 a.a.) is primarily used in laboratory research to study the alternative pathway of the complement system. It is not intended for use as a drug, agricultural or pesticidal product, food additive, or household chemical .