title: Engineered-membranes: a novel concept for clustering of native lipid bilayers.
abstract: A strategy for clustering of native lipid membranes is presented. It relies on the formation of complexes between hydrophobic chelators embedded within the lipid bilayer and metal cations in the aqueous phase, capable of binding two (or more) chelators simultaneously Fig. 1. We used this approach with purple membranes containing the light driven proton pump protein bacteriorhodopsin (bR) and showed that patches of purple membranes cluster into mm sized aggregates and that these are stable for months when incubated at 19°C in the dark. The strategy may be general since four different hydrophobic chelators (1,10-phenanthroline, bathophenanthroline, Phen-C10, and 8-hydroxyquinoline) and various divalent cations (Ni(2+), Zn(2+), Cd(2+), Mn(2+), and Cu(2+)) induced formation of membrane clusters. Moreover, the absolute requirement for a hydrophobic chelator and the appropriate metal cations was demonstrated with light and atomic force microscopy (AFM); the presence of the metal does not appear to affect the functional state of the protein. The potential utility of the approach as an alternative to assembled lipid bilayers is suggested.
authors.affiliation: Department of Biological Chemistry, Ariel University Center of Samaria, 70400 Ariel, Israel. guyp@ariel.ac.il
authors.forename: Guy
authors.initials: G
authors.lastname: Patchornik
authors.forename: Irishi N N
authors.initials: IN
authors.lastname: Namboothiri
authors.forename: Divya K
authors.initials: DK
authors.lastname: Nair
authors.forename: Ellen
authors.initials: E
authors.lastname: Wachtel
authors.forename: Sidney R
authors.initials: SR
authors.lastname: Cohen
authors.forename: Noga
authors.initials: N
authors.lastname: Friedman
authors.forename: Mordechai
authors.initials: M
authors.lastname: Sheves
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D002413:Cations, Divalent / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010782:Photolysis; D018717:Purple Membrane / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D002614:Chelating Agents; D008051:Lipid Bilayers; D008563:Membrane Lipids; D001436:Bacteriorhodopsins