Complement Component 8 gamma Chain

Complement component 8 gamma chain, encoded by C8G, is the smallest subunit of C8 and a member of the lipocalin protein family. It is disulfide-bonded to the alpha chain, forming the alpha-gamma subunit that, together with beta, constitutes mature C8. Its lipocalin fold suggests a capacity to bind small hydrophobic ligands, and the gamma chain is thought to modulate C8 activity and stability within the membrane attack complex rather than driving membrane insertion itself. C8 gamma circulates in plasma as part of C8 and can also be found in association with lipoproteins. Recombinant C8 gamma supports structural and MAC-assembly studies.