Development of Long, Stiff DNA Tubes as Nanopatterned Substrates for Protein Binding

We describe progress towards developing DNA Nanotubes into a tool for nano-patterning and assaying protein binding. DNA nanotubes are uniquely accessible equilibrium polymers made of motifs known as double- crossovers (DX units). They are typically 10 nm in diameter, up to 100 microns in length and correspondingly stiff (persistence length longer than 5 microns). We have predicted and thereby manipulated the tube-structure to selectively decorate the tubes along the interior or the exterior surface. This ability allows us to use DNA tubes as protein-binding substrates with unusually high density of binding-sites (around 500 within a micron), arrayed along the exterior of a tube in a regular lattice of 14.5 nm x 4 nm. We describe results showing the use of DNA Nanotubes as substrates for proteins such as ligase, restriction enzymes and regulatory proteins.