title: High-Resolution Size-Discrimination of Single Nonionic Synthetic Polymers with a Highly Charged Biological Nanopore.
abstract: Electrophysiological studies of the interaction of polymers with pores formed by bacterial toxins (1) provide a window on single molecule interaction with proteins in real time, (2) report on the behavior of macromolecules in confinement, and (3) enable label-free single molecule sensing. Using pores formed by the staphylococcal toxin α-hemolysin (aHL), a particularly pertinent observation was that, under high salt conditions (3-4 M KCl), the current through the pore is blocked for periods of hundreds of microseconds to milliseconds by poly(ethylene glycol) (PEG) oligomers (degree of polymerization approximately 10-60). Notably, this block showed monomeric sensitivity on the degree of polymerization of individual oligomers, allowing the construction of size or mass spectra from the residual current values. Here, we show that the current through the pore formed by aerolysin (AeL) from Aeromonas hydrophila is also blocked by PEG but with drastic differences in the voltage-dependence of the interaction. In contrast to aHL, AeL strongly binds PEG at high transmembrane voltages. This fact, which is likely related to AeL's highly charged pore wall, allows discrimination of polymer sizes with particularly high resolution. Multiple applications are now conceivable with this pore to screen various nonionic or charged polymers.
authors.affiliation: ‡Ionera Technologies GmbH, Hermann Herder Strasse 7, 79104 Freiburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Baaken
authors.affiliation: ‡Ionera Technologies GmbH, Hermann Herder Strasse 7, 79104 Freiburg, Germany.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Halimeh
authors.affiliation: §Laboratoire LAMBE, Équipe Polymères aux Interfaces, LAMBE UMR 8587 CNRS, Évry and Cergy University, Cergy-Pontoise 95011 cedex, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bacri
authors.affiliation: §Laboratoire LAMBE, Équipe Polymères aux Interfaces, LAMBE UMR 8587 CNRS, Évry and Cergy University, Cergy-Pontoise 95011 cedex, France.
authors.forename: Juan
authors.initials: J
authors.lastname: Pelta
authors.affiliation: §Laboratoire LAMBE, Équipe Polymères aux Interfaces, LAMBE UMR 8587 CNRS, Évry and Cergy University, Cergy-Pontoise 95011 cedex, France.
authors.forename: Abdelghani
authors.initials: A
authors.lastname: Oukhaled
authors.affiliation: ∥Freiburg Materials Research Centre (FMF), University of Freiburg, Stefan-Meier-Strasse 21, 79104 Freiburg, Germany.|⊥Centre for Interactive Materials and Bioinspired Technologies (FIT), Georges-Köhler-Allee 105, 79110 Freiburg, Germany.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Behrends
mesh_terms: D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D006460:Hemolysin Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D058608:Nanopores; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D052899:Pore Forming Cytotoxic Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry; D013329:Structure-Activity Relationship; D013499:Surface Properties
chemical_list: D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D052899:Pore Forming Cytotoxic Proteins; C021091:staphylococcal alpha-toxin; D011092:Polyethylene Glycols; C032676:aerolysin
keywords: aerolysin; ionic sensing; mass spectrometry; nanopore; poly(ethylene glycol); α-hemoylsin