Complement component C6 (C6)

Complement component C6 is a single-chain plasma glycoprotein composed of 913 amino acids, essential for the assembly and function of the membrane attack complex (MAC) in the terminal pathway of complement activation. C6 binds non-proteolytically to C5b to form the C5b-6 complex, nucleating MAC assembly, followed by recruitment of C7, C8, and multiple C9 molecules. The MAC forms lytic pores in pathogen membranes, providing innate immunity through direct cell killing. Structurally, C6 is a member of the membrane attack complex/perforin (MACPF) superfamily, sharing domain organization and sequence similarity with C7, C8, and C9. C6 has emerging roles in non-lytic signaling, inflammation, cancer, and neurodegeneration. Inhibiting C6 offers a targeted therapeutic strategy to block cell lysis while preserving upstream complement functions such as opsonization and chemotaxis, but raises concerns about infection risk due to impaired terminal complement activity[1][2][3].

Other names

Complement C6C6complement component 6complement component C6sixth component of complement

Inhibition of MAC assembly (by blocking the interaction of C6 with C5b or subsequent MAC components); Prevention of pore formation and complement-mediated cytolysis