Mechanisms of attack and defence at the cell surface: the use of phospholipid bilayers as models for cell membrane.

Electrical conductivity across phospholipid bilayers induced by various cytotoxic proteins has been used to analyse the damaging action of such proteins on cells; the protective effect of divalent cations and protons against such attack has also been investigated. The predominant effect of divalent cations and protons is to promote the closed state of membrane pores, i.e. to "gate" protein-induced lesions.