DNA-assisted oligomerization of pore-forming toxin monomers into precisely-controlled protein channels

We have developed a novel approach for creating membrane-spanning protein-based pores. The construction principle is based on using well-defined, circular DNA nanostructures to arrange a precise number of pore-forming protein toxin monomers. We can thereby obtain, for the first time, protein pores with specifically set diameters. We demonstrate this principle by constructing artificial alpha-hemolysin (alpha HL) pores. The DNA/alpha HL hybrid nanopores composed of twelve, twenty or twenty-six monomers show stable insertions into lipid bilayers during electrical recordings, along with steady, pore size-dependent current levels. Our approach successfully advances the applicability of nanopores, in particular towards label-free studies of single molecules in large nanoscaled biological structures.