Browse our C8A Proteins (C8A)

Human Complement Component 8, alpha Polypeptide (C8A) interaction partners

1. C8 alpha and C8 beta have correspondingly similar roles in MAC-mediated lysis of erythrocytes and bacterial killing. C8 gamma is not required for complement-mediated killing of Gram-negative bacteria.

2. Results describe the crystal structure of the human C8 alpha MACPF domain disulfide-linked to C8 gamma (alphaMACPF-gamma) at 2.15 A resolution.

3. The binding specificity between C8 alpha and C8 beta subunits is determined by a cooperative interaction of the N-terminal thrombospondin type 1 module and the membrane attack complex/perforin domain.

4. Both N-terminal modules in C8 alpha have a role in forming the principal binding site for C9, and binding may be dependent on a cooperative interaction between these modules and the C8 alpha membrane attack complex/perforin domain.

5. result suggests that this segment of C8alpha and corresponding segments of the other MAC family members are independently folded domains

6. One can predict that the indel segment of C8alpha assumes a conformation that allows for multiple points of contact with C8gamma.

7. crystal structure of the MACPF domain of complement component C8alpha at 2.5 angstrom resolution was determined and it was shown that it is structurally homologous to the bacterial, pore-forming, cholesterol-dependent cytolysins

8. C8gamma binds an indel peptide of C8alpha sequence and forms a non-covalent complex.