Complement Component 5 (C5)

Complement component 5 is a protein involved in the complement system.C5 is a 190-kD glycoprotein comprised of 2 disulfide-linked polypeptide chains, alpha (C5a) and beta (C5b), with a molecular mass of 155 and 75 kD, respectively (Tack et al., 1979). Haviland et al. (1991) constructed the complete cDNA sequence of human complement pro-C5, which is predicted to encode a 1,676-amino acid promolecule that contains an 18-amino acid leader peptide and a 4-amino acid linker separating the beta and alpha chains.

Northern blot analysis demonstrated a major 6.0-kb C5 transcript, as well as 3.0-kb and 4.8-kb transcripts. Carney et al. (1991) determined that the C5 gene contains 41 exons that span a genomic region of 79 kb.