Transmembrane anion transport mediated by halogen-bond donors.
In biology and chemistry, the transport of anions across lipid bilayer membranes is usually achieved by sophisticated supramolecular architectures. Significant size reduction of transporters is hampered by the intrinsically hydrophilic nature of typical anion-binding functionalities, hydrogen-bond donors or cations. To maximize the atom efficiency of anion transport, the hydrophobic nature, directionality, and strength of halogen bonds seem promising. Unlike the ubiquitous, structurally similar hydrogen bonds, halogen bonds have not been explored for anion transport. Here we report that transport across lipid bilayers can be achieved with small perfluorinated molecules that are equipped with strong halogen-bond donors. Transport is observed with trifluoroiodomethane (boiling point=-22 °C); that is, it acts as a 'single-carbon' transporter. Contrary to the destructive action of small-molecule detergents, transport with halogen bonds is leakage-free, cooperative, non-ohmic and highly selective, with anion/cation permeability ratios <37.
Department of Organic Chemistry, University of Geneva, Geneva CH-1211, Switzerland.
Andreas Vargas
AV
Jentzsch
Daniel
D
Emery
Jiri
J
Mareda
Susanta K
SK
Nayak
Pierangelo
P
Metrangolo
Giuseppe
G
Resnati
Naomi
N
Sakai
Stefan
S
Matile
D000838:Anions / Q000737:chemistry*; D006219:Halogens / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000737:chemistry; D006860:Hydrogen Bonding; D017136:Ion Transport / Q000502:physiology*; D008051:Lipid Bilayers / Q000737:chemistry*; D008958:Models, Molecular
D000838:Anions; D006219:Halogens; D006846:Hydrocarbons, Halogenated; D008051:Lipid Bilayers; C105057:trifluoroiodomethane