Triton channels are sensitive to divalent cations and protons

Addition of Triton X-100 to planar bilayers composed of dioleoyl phosphatidyl choline, diphytanoyl phosphatidyl choline or mono-oleoyl glycerol induces single channel-like events when electrical conductivity across the bilayer is measured. Addition of divalent cations or protons causes channels to disappear; single channel conductance of remaining channels is not significantly altered; addition of EDTA or alkali (respectively) reverses the effect. It is concluded that sensitivity to divalent cations and protons need not be dependent on specific channel proteins or pore-forming toxins, but may be a feature of any aqueous pore across a lipid milieu.We are grateful to Dr. D.T. Edmonds and Prof. R.J.P. Williams for critical discussion, to Glenn Alder for technical assistance, to Ms. B. Bashford and Ms. S.G. Pelc for preparing the paper, and to the Cell Surface Research Fund, the Royal Society (A.A.L.), UNESCO (Molecular and Cell Biology Network) and The Wellcome Trust for financial support.