Complement Component C9 Novocastra
Complement component C9 binds to the C5b-8 complex as the final protein of the membrane attack complex. After binding, it undergoes a conformational change and inserts itself into the cell membrane, forming transmembrane channels. Complement component C9 acts in a similar way to perforin, a pore forming protein found in cytotoxic T cells. Male and female reproductive tissues express and synthesize complement components, binding proteins and receptors, although the implications of this is unclear. The detection of complement component C9 has been reported in cases of acute myocardial damage at necropsy. Detection of myocardial infarction or diffuse damage can be unreliable with conventional methods of examination of the heart such as enzyme histochemistry or by the elaborate technique of quantification of contraction band necrosis.