title: Optical waveguide lightmode spectroscopic techniques for investigating membrane-bound ion channel activities.
abstract: Optical waveguide lightmode spectroscopic (OWLS) techniques were probed for monitoring ion permeation through channels incorporated into artificial lipid environment. A novel sensor set-up was developed by depositing liposomes or cell-derived membrane fragments onto hydrophilic polytetrafluoroethylene (PTFE) membrane. The fibrous material of PTFE membrane could entrap lipoid vesicles and the water-filled pores provided environment for the hydrophilic domains of lipid-embedded proteins. The sensor surface was kept clean from the lipid holder PTFE membrane by a water- and ion-permeable polyethylene terephthalate (PET) mesh. The sensor set-up was tested with egg yolk lecithin liposomes containing gramicidin ion channels and with cell-derived membrane fragments enriched in GABA-gated anion channels. The method allowed monitoring the move of Na(+) and organic cations through gramicidin channels and detecting the Cl(-)-channel functions of the (α5β2γ2) GABAA receptor in the presence or absence of GABA and the competitive GABA-blocker bicuculline.
authors: Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
authors: Inna
authors: I
authors: Székács
authors: Nóra
authors: N
authors: Kaszás
authors: Pál
authors: P
authors: Gróf
authors: Katalin
authors: K
authors: Erdélyi
authors: István
authors: I
authors: Szendrő
authors: Balázs
authors: B
authors: Mihalik
authors: Agnes
authors: A
authors: Pataki
authors: Ferenc A
authors: FA
authors: Antoni
authors: Emilia
authors: E
authors: Madarász
mesh_terms: D002462:Cell Membrane / Q000378:metabolism*; D006096:Gramicidin / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D007834:Lasers; D008081:Liposomes / Q000378:metabolism; D009068:Movement; D055096:Optical Devices; D011485:Protein Binding; D011963:Receptors, GABA-A / Q000378:metabolism
chemical_list: D007473:Ion Channels; D008081:Liposomes; D011963:Receptors, GABA-A; D006096:Gramicidin