Cover picture: Inside the pore views of the junction between two gramicidin A peptides which were covalently linked with a dioxolane group (carbons in yellow). Representative molecular models of the SS and the RR stereoisomers of the gramicidin A dimers are shown in the left and right panels, respectively. These molecules form ion channels in lipid bilayers with markedly different proton conduction and gating properties. (See the article by Quigley et al. on p. 2479.