title: Controlling the translocation of single-stranded DNA through alpha-hemolysin ion channels using viscosity.
abstract: Translocation of single-stranded DNA through alpha-hemolysin (alpha-HL) channels is investigated in glycerol/water mixtures containing 1 M KCl. Experiments using glass nanopore membranes as the lipid bilayer support demonstrate that the translocation velocities of poly(deoxyadenylic acid), poly(deoxycytidylic acid), and poly(deoxythymidylic acid) 50-mers are decreased by a factor of approximately 20 in a 63/37 (vol %) glycerol/water mixture, relative to aqueous solutions. The ion conductance of alpha-HL and the entry rate of the polynucleotides into the protein channel also decrease with increasing viscosity. Precise control of translocation parameters by adjusting viscosity provides a potential means to improve sequencing methods based on ion channel recordings.
authors.affiliation: Department of Chemistry, University of Utah, 315S. 1400E, Salt Lake City, Utah 84112, USA. rjkawano@chem.utah.edu
authors.forename: Ryuji
authors.initials: R
authors.lastname: Kawano
authors.forename: Anna E P
authors.initials: AE
authors.lastname: Schibel
authors.forename: Christopher
authors.initials: C
authors.lastname: Cauley
authors.forename: Henry S
authors.initials: HS
authors.lastname: White
mesh_terms: D004277:DNA, Single-Stranded / Q000737:chemistry*; D005898:Glass / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry; D006460:Hemolysin Proteins / Q000737:chemistry*; D007473:Ion Channels / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008567:Membranes, Artificial; D044367:Phase Transition; D011119:Polynucleotides / Q000737:chemistry; D016062:Porosity; D011189:Potassium Chloride / Q000737:chemistry; D013499:Surface Properties; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D004277:DNA, Single-Stranded; D006460:Hemolysin Proteins; D007473:Ion Channels; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D011119:Polynucleotides; D014867:Water; D011189:Potassium Chloride; D005990:Glycerol