Anti-Human FHR4 Polyclonal Antibody-10 mg (CAT#: CB-P540-K) Datasheet

Antibody

The polyclonal antibody recognizes human complement factor H-related protein 4 (FHR4). The complement system is the first line of defense against pathogens, helping to eliminate apoptosis and damaged cells. Complement factor H (fH) is an abundant plasma protein that can negatively regulate the alternative pathway and C3b amplification loop. In addition to fH, the proteins encoded by the fH gene family include five fH-related proteins (FHR1-5), which are encoded by closely connected but unique genes. Like fH, these proteins are composed of repetitive short consensus repeat sequences (SCR). fH competes with fB to bind to C3b and C3b (H2O), thereby preventing the formation of invertase, accelerating the degradation of C3 invertase, and is a cofactor of fI. The function of FHR protein is unclear. FHRs are mainly produced in the liver and secreted in the plasma. FHR4 binds to the C3d region of C3b. In contrast to fH, FHR4-C3b interaction promotes complement activation. Two transcripts of the FHR4 gene exist: FHR4B and FHR4B, which are composed of 9 and 5 SCRs (86 and 42 kDa) respectively. The two variants have different binding profiles for C3b. The proposed FHR4 complement activating ligand is pentameric CRP.