title: Fluorinated amphiphiles control the insertion of α-hemolysin pores into lipid bilayers.
abstract: The insertion of fully folded and assembled ion channels and pores into planar lipid bilayers for electrical recording has been facilitated by the use of conventional detergents at a final concentration below the critical micelle concentration (CMC). After the desired number of channels or pores (often one) has been incorporated into a bilayer, it is important to prevent further insertion events, which is often done by awkward techniques such as perfusion. Here, we show that the addition of single-chain fluorinated amphiphiles (F-amphiphiles) with zwitterionic, simple neutral, and neutral oligomeric headgroups at a concentration above the CMC prevents the further insertion of staphylococcal α-hemolysin pores, MspA pores, and Kcv potassium channels into lipid bilayers. We found the commercially available F(6)FC (fluorinated fos-choline with a C(6)F(13)C(2)H(4) chain) to be the least perturbing and most effective agent for this purpose. Bilayers are known to be resistant to F-amphiphiles, which in this case we suppose sequester the pores and channels within amphiphile aggregates. We suggest that F-amphiphiles might be useful in the fabrication of bilayer arrays for nanopore sensor devices and the rapid screening of membrane proteins.
authors.affiliation: Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom.
authors.forename: Pinky
authors.initials: P
authors.lastname: Raychaudhuri
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Li
authors.forename: Amy
authors.initials: A
authors.lastname: Mason
authors.forename: Ellina
authors.initials: E
authors.lastname: Mikhailova
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Heron
authors.forename: Hagan
authors.initials: H
authors.lastname: Bayley
mesh_terms: D001427:Bacterial Toxins / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry*; D006460:Hemolysin Proteins / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D015394:Molecular Structure; D016062:Porosity; D055550:Protein Stability; D013211:Staphylococcus aureus / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D001427:Bacterial Toxins; D006460:Hemolysin Proteins; D008051:Lipid Bilayers; D013501:Surface-Active Agents; D047392:beta-Cyclodextrins; C021091:staphylococcal alpha-toxin; C031215:betadex