Anti-C3 antibody [11H9]

Supplementary info

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

Activity summary

Complement component 3 (C3) commonly known as C3 complement is a central protein in the complement system which plays a significant role in immune response. C3b a fragment of C3 is produced when C3 undergoes cleavage. C3 is a large protein with a mass of approximately 185 kDa. The liver primarily secretes C3 into the bloodstream. It circulates in the plasma and is found in high concentration making it one of the most abundant components of the complement system.

Biological function summary

Complement component C3 forms part of the innate immune system by promoting opsonization which enhances phagocytosis of pathogens. C3b binds to pathogens' surfaces facilitating their recognition by phagocytes. C3 as part of a complex with C3 convertase also has a role in amplifying the activation of the complement cascade. The proteolytic cleavage of C3 into C3b and C3a leads to the activation of other components forming the membrane attack complex and orchestrating inflammation.

Pathways

The complement component C3 functions within both the classical and alternative complement pathways. It acts as a convergence point where the complement activation pathways meet. C3 is activated into C3b and C3a which are key to amplifying the cascade. Furthermore C3 interacts with proteins such as factor B and factor D in the alternative pathway and C4 and C2 in the classical pathway facilitating the formation of C3 convertase necessary for pathway progression.

Associated diseases and disorders

Complement C3 shows associations with immune-related and inflammatory diseases. Deficiencies or malfunctions of complement C3 can lead to increased susceptibility to infections due to impaired opsonization and clearance of pathogens. Additionally overactivation of the complement system involving C3 can contribute to autoimmune disorders such as systemic lupus erythematosus. Other proteins linked to these diseases include C4 in lupus and factor H in age-related macular degeneration which controls complement pathway activation.