Structure and assembly of membrane proteins in native membranes by atomic force microscopy (AFM)

Keywords: atomic force microscopy, membrane protein, membrane structure, supramolecular assembly

Read the scientific activity report. (pdf 230Ko, last update 9th, february 2010)

Around 30% of the open reading frames in the human genome encode membrane proteins, and this class of proteins is implicated in many of life's most important processes: signalling, energy transduction, metabolite transport, to name but a few. They are, therefore, the target of the majority of drugs used nowadays and defects in membrane protein function underlie directly or indirectly many pathologies. Our team studies the structure and assembly of membrane proteins in native membranes by high-resolution atomic force microscopy (AFM) imaging and force spectroscopy.

One enormous advantage of AFM over other high-resolution imaging techniques is that it can be performed in physiological buffers at room temperature and under normal pressure. AFM measurements also have an outstanding signal-to-noise ratio. Together, these features allow us to visualise individual membrane proteins directly in their natural environment, the native membrane. Here, large supramolecular assemblies - nanomachines comprising several membrane proteins working together - can be observed by AFM to great effect.

Supramolecular assemblies function in signal and energy transduction with impressive efficiency. Recently, we reported high-resolution images of a photosynthetic membrane (Fig. 1) and its adaptation to various levels of illumination as well as the supramolecular assembly of membrane proteins in junctional microdomains in the lens membranes of the eye (Fig. 2). We have also developed a two-chamber setup that allows a single membrane bilayer between two aqueous compartments to be imaged by AFM.

Fig. 1

Fig. 2

We plan to develop AFM as a biomedical imaging and force probe tool. In the long term, we aim to perform high-resolution imaging of natural cytoplasmic membranes.

Personal lab web page: perso.curie.fr/Simon.Scheuring

Last update: February 2010

Key publications

2009

• Casuso I, Scheuring S
  Automated setpoint adjustment for biological contact mode AFM imaging
  Nanotechnology, 21 (3): 35104-35111

2007

• Nikolay Buzhynskyy, Jean-Francois Girmens, Wolfgang Faigle, and Simon Scheuring*
  Human cataract lens membrane at subnanometer resolution
  Journal of Molecular Biology, 2007, 374 (1): 162-169
• Nikolay Buzhynskyy, Richard Hite, Thomas Walz, and Simon Scheuring
  The supramolecular architecture of junctional microdomains in native lens membranes
  EMBO Reports, 8 (1): 51-55

2006

• Rui Pedro Gonçalves, Guillaume Agnus, Pierre Sens, Christine Houssin, Bernard Bartenlian & Simon Scheuring*
  Two-Chamber AFM: probing membrane proteins separating two aqueous compartments
  Nature Methods, 3, 1007-1012

2005

• Simon Scheuring*, & James Sturgis
  Chromatic adaptation of photosynthetic membranes
  Science, 309 (5733): 484-487