Sampling the conformational space of membrane protein surfaces with the AFM.
The atomic force microscope acquires topographs of single native membrane proteins at subnanometer resolution. Owing to the high signal-to-noise ratio, such images allow the conformational space of membrane protein surfaces to be sampled. This is demonstrated by topographs of porin OmpF, aquaporin-Z, and bacteriorhodopsin, all recorded at a lateral resolution of <7 A and a vertical resolution of ~1 A. The amplitudes of the domain movements were estimated from a large number of single molecule topographs and the corresponding energy landscapes calculated. To visualize the motion of protein domains, movies were generated by similarity ranking of the observed protein configurations. Electronic supplementary material to this paper can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00249-001-0197-8
Scheuring
Simon
S
M.E. Müller Institute for Microscopy at the Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland.
Müller
Daniel J
DJ
Stahlberg
Henning
H
Engel
Hans-Andreas
HA
Engel
Andreas
A
D020346:Aquaporins / Q000737:chemistry; D001436:Bacteriorhodopsins / Q000737:chemistry; D029968:Escherichia coli Proteins; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008565:Membrane Proteins / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D009038:Motion; D036103:Nanotechnology; D018272:Porins / Q000737:chemistry; D011487:Protein Conformation
D020346:Aquaporins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D018272:Porins; C106425:aqpZ protein, E coli; D001436:Bacteriorhodopsins