Synthetic Lipid Membrane Channels Formed by Designed DNA Nanostructures

1. Martin Langecker¹,*, 
2. Vera Arnaut¹,*, 
3. Thomas G. Martin²,*, 
4. Jonathan List¹, 
5. Stephan Renner¹, 
6. Michael Mayer³,
7. Hendrik Dietz²,†, 
8. Friedrich C. Simmel¹,†

Science 16 November 2012: 
Vol. 338 no. 6109 pp. 932-936 
DOI: 10.1126/science.1225624

ABSTRACT

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.