Membrane attack complex (of complement system)
Chapter: 2
The terminal proteins in the complement cascade (C5b,6,7,8, and 9) form a lipid-soluble macromolecular protein channel that permeabilizes cell membranes. It can affect the membranes of both bacterial and mammalian cells. When the permeability of the cell under attack is lost, osmotic control is lost, the consequence of which is rapid cell lysis.