Friday, 16 November, 2012
Synthetic Lipid Membrane Channels Formed by Designed DNA Nanostructures
M. Langecker, V. Arnaut, T. Martin, J. List, S. Renner, M. Mayer, H. Dietz, F. Simmel -
Science, Vol. 338 (6109), pp. 932-936 (2012)
We created nanometer-scale transmembrane channels in lipid bilayers by means of self-assembled DNA-based nanostructures. Scaffolded DNA origami was used to create a stem that penetrated and spanned a lipid membrane, as well as a barrel-shaped cap that adhered to the membrane, in part via 26 cholesterol moieties. In single-channel electrophysiological measurements, we found similarities to the response of natural ion channels, such as conductances on the order of 1 nanosiemens and channel gating. More pronounced gating was seen for mutations in which a single DNA strand of the stem protruded into the channel. Single-molecule translocation experiments show that the synthetic channels can be used to discriminate single DNA molecules.