Anti-C3 / C3b antibody [755]

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

C3 also known as complement C3 or anti C3b is a central protein in the complement system with an approximate molecular mass of 187 kDa. This protein exists in blood plasma as an inactive precursor and is produced mainly in the liver. C3 gets activated through cleavage into two fragments C3a and C3b. The functional fragment C3b covalently attaches to pathogen surfaces through a process called opsonization allowing it to 'tag' pathogens for destruction by immune cells.

Biological function summary

Complement C3b plays an integral role in innate immunity. C3b is a part of the complement cascade forming complexes such as C3bBb which acts as a convertase in the amplification of the complement response. Through opsonization C3b promotes the binding and uptake of pathogens by phagocytes therefore enhancing immune defense.

Pathways

C3b integrates into the alternative and classical complement pathways. In these pathways C3b binds with factors like B and D contributing to the formation of the C5 convertase and progressing to the membrane attack complex. These interactions involve proteins such as C5 and Factor B essential for the effective destruction of pathogens and the clearance of immune complexes.

Associated diseases and disorders

Complement C3b shows associations with diseases involving improper immune regulation such as atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD). Mutations affecting C3b's interactions with regulatory proteins such as Factor H can lead to uncontrolled complement activation which contributes to the pathology of these diseases. Understanding these interactions provides insights into therapeutic targets for managing complement-related diseases.