Ca2+ and the interaction of pore-formers with membranes.

ABSTRACT

The interaction of pore-forming agents, such as Sendai virus, influenza virus (at pH 5 3), activated complement, Staphylococcus aureus α-toxin, melittin and polylysine, with the surface membrane of cells has been studied. In each case the following changes are initiated collapse of membrane potential, leakage of ions, and leakage of phosphorylated metabolites. The changes can be inihibited by extracellular Ca2+ at physiological concentration; Mg2+ is less effective, and Zn2+ is more effective, than Ca2+ Ca2+ appears to act at a stage subsequent to the binding of pore-forming agent to cells. It is concluded that divalent cations are able to protect cells against the damaging effects of certain viruses, toxins or the components of activated complement in a manner that is worthy of further investigation.