Complement Component 8 alpha
null Complement component 8 alpha is one of the three chains of C8, the first component committed to the membrane attack complex. Encoded by C8A, the alpha chain is disulfide-linked to the gamma chain, and this alpha-gamma pair binds the beta chain to complete C8. Upon recruitment to the C5b-7 complex on a target membrane, C8 inserts into the lipid bilayer, with the alpha chain contributing to membrane penetration and nucleating the polymerization of C9 into the cytolytic pore. Hereditary deficiency of C8 alpha causes complement insufficiency and recurrent Neisseria infections. Recombinant C8 alpha supports MAC assembly and deficiency studies.
