Recombinant Human C8a (Complement C8a) Protein Standard

Supplementary information

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

Complement C8a also known as C8 alpha chain is a part of the complement system which plays a role in immune response. It has a molecular mass of approximately 64 kDa. This protein is found in blood plasma and is mainly expressed in hepatocytes. The C8a forms the terminal subunit of the C8 protein complex which is critical for the formation of the membrane attack complex (MAC) that disrupts the lipid bilayer of target cells.

Biological function summary

The C8a chain works in concert with C8 beta and C8 gamma to form the C8 complex of the complement system. This protein becomes part of the larger MAC a lytic complex that facilitates cell membrane disruptions thereby initiating cell lysis. The membrane attack complex plays a defensive role against pathogenic microorganisms contributing to innate immunity.

Pathways

The complement system involving C8a plays a central role in the innate immune pathway and the alternative pathway of complement activation. These pathways are essential for the protection against infections. The C5 convertase acts upstream of C8a cleaving C5 to C5b which then associates with C6 and C7 allowing C8a and its counterparts C8b and C8g to bind and initiate MAC formation. C9 is the final protein to bind completing the complex and resulting in the lysis of the target.

The deficiency or dysfunction in C8a can be associated with increased susceptibility to Neisseria infections particularly meningococcal disease. C8 deficiency is often linked with deficiencies in C5-C9 proteins as these proteins are collectively critical for functional MAC formation. Immunological responses depending on the formation of the MAC can become compromised increasing vulnerability to certain bacterial infections.