Immunogen sequence: MEPPGRRECP FPSWRFPGLL LAAMVLLLYS FSDACEEPPT FEAMELIGKP KPYYEIGERV DYKCKKGYFY IPPLATHTIC DRNHTWLPVS DDACYRETCP. CD46 (MCP, membrane cofactor protein) is a multifunctional cell surface transmembrane protein that binds and inactivates C3