title: Probing DNA-lipid membrane interactions with a lipopeptide nanopore.
abstract: Association of DNA molecules with lipid bilayer membranes is of considerable interest for a large variety of applications in biotechnology. Here we introduce syringomycin E (SRE), a small pore-forming lipopeptide produced by the bacterium Pseudomonas syringae, as a facile sensor for the detection of DNA interactions with lipid membranes. SRE forms highly reproducible pores in cellular and artificial membranes. The pore structure involves bilayer lipids, which have a pronounced influence on open channel conductance and gating. SRE channels act as ionic diodes that serve as current rectifiers sensitive to the charge of the bilayer. We employ this intrinsic property to electronically monitor the association of DNA molecules with the membrane in a variety of different settings. We show that SRE can be used for quantitatively probing electrostatic interactions of DNA and DNA-cholesterol conjugates with a lipid membrane. Furthermore, we demonstrate that SRE channels allow monitoring of hybridization reactions between lipid-anchored probe strands and complementary strands in solution. In the presence of double-stranded DNA, SRE channels display a particularly high degree of rectification. Finally, the formation of multilayered structures assembled from poly-(L)-lysine and DNA oligonucleotides on the membrane was precisely monitored with SRE.
authors.affiliation: Physics Department E14 and ZNN/WSI, Technische Universität München, Am Coulombwall 4a, 85748, Garching, Germany. andrey.bessonov@ph.tum.de
authors.forename: Andrey
authors.initials: A
authors.lastname: Bessonov
authors.forename: Jon Y
authors.initials: JY
authors.lastname: Takemoto
authors.forename: Friedrich C
authors.initials: FC
authors.lastname: Simmel
mesh_terms: D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004553:Electric Conductivity; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D055666:Lipopeptides / Q000737:chemistry / Q000378:metabolism*; D058608:Nanopores; D036103:Nanotechnology / Q000379:methods*; D009693:Nucleic Acid Hybridization
chemical_list: D008051:Lipid Bilayers; D055666:Lipopeptides; D004247:DNA