title: Ion selectivity of pore-forming peptides and ion channels measured in Xenopus oocytes.
abstract: The Xenopus laevis oocyte is a widely used system for heterologous expression of exogenous ion channel proteins. They are easy to obtain, mechanically and electrically stable, have a large size, enabling multiple types of electrophysiological recordings: two-electrode voltage clamp, single cell-attached or cell-free patch-clamp and macropatch recordings. The size of an oocyte (1 mm in diameter) also allows for the use of additional electrodes (from 1 to 3) for injection of diverse materials (Ca(2+) chelators, peptides, chemicals, antibodies, proteic-partners, etc.) before or during the course of the electrophysiological experiment.We have successfully used this system to analyze the biophysical properties of pore-forming peptides. Simple extracellular perfusion of these peptides induced the formation of channels in the oocyte plasma membrane; these channels can then be studied and characterized in diverse ionic conditions. The ease of the perfusion and the stability of the voltage-clamped oocyte make it a powerful tool for such analyses. Compared to artificial bilayers, oocytes offer a real animal plasma membrane where biophysical properties and toxicity can be studied in the stable environment.
authors.affiliation: Centre de Recherche de Biochimie Macromoleculaire - UMR 5237- CNRS, 1919 Route de Mende, 34293, Montpellier, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Cens
authors.forename: Pierre
authors.initials: P
authors.lastname: Charnet
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000378:metabolism*; D002469:Cell Separation / Q000379:methods; D004594:Electrophysiology / Q000379:methods; D005260:Female; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods*; D010455:Peptides / Q000494:pharmacology*; D014982:Xenopus laevis / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; D010455:Peptides