Voltage-induced morphological modifications in oocyte membranes containing exogenous K+ channels studied by electrochemical scanning force microscopy

Authors

  • Andrea Alessandrini,

    1. National Research Council – National Institute for the Physics of Matter, Center “nanoStructures and bioSystems at Surfaces – S3” Modena, Italy
    2. Department of Physics, University of Modena and Reggio Emilia, Modena, Italy
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  • Paola Gavazzo,

    1. National Research Council, Insitute of Biophysics, Genova, Italy
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  • Cristiana Picco,

    1. National Research Council, Insitute of Biophysics, Genova, Italy
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  • Paolo Facci

    Corresponding author
    1. National Research Council – National Institute for the Physics of Matter, Center “nanoStructures and bioSystems at Surfaces – S3” Modena, Italy
    • CNR-INFM National Centre “nanoStructures and bioSystems at Surfaces – S3,” Via G. Campi, 213/A, I-41100 Modena, Italy
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Abstract

We report on a novel use of electrochemical scanning force microscopy (SFM) for the investigation of morphological modifications occurring in plasma membranes containing voltage-gated ion channels, on membrane potential variation. Membrane patches of Xenopus laevis oocytes microinjected with exogenous KAT1 cRNA, deposited by a stripping method at the surface of a derivatized gold film in inside-out configuration, have been imaged by SFM in an electrochemical cell. A potentiostat was used to maintain a desired potential drop across the membrane. Performing imaging at potential values corresponding to open (−120 mV) and closed (+20 mV) states for KAT1, morphological differences in localized sample zones were observed. Particularly, cross-shaped features involving a significant membrane portion appear around putative channel locations. The reported approach constitutes the first demonstration of an SPM-based experimental technique suitable to investigate the rearrangements occurring to the plasma membrane containing voltage-gated channels on transmembrane potential variation. Microsc. Res. Tech., 2008. © 2007 Wiley-Liss, Inc.

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