AVS 52nd International Symposium
    Biomaterials Plenary Sunday Sessions
       Session BP-SuA

Invited Paper BP-SuA3
Observing Membrane-Embedded Biological Nanomachines Using the AFM

Sunday, October 30, 2005, 3:40 pm, Room 312

Session: Biomaterials Interfaces Plenary Session
Presenter: A. Engel, M.E. Mueller Institute, Switzerland
Authors: D. Fotiadis, M.E. Mueller Institute, Switzerland
P.N.T.L. Frederix, M.E. Mueller Institute, Switzerland
H. Remigy, M.E. Mueller Institute, Switzerland
A. Engel, M.E. Mueller Institute, Switzerland
Correspondent: Click to Email
Membrane proteins are membrane-embedded nanomachines at cellular interfaces that fulfill key functions such as energy conversion, solute transport, secretion, and signal transduction. The lack of structural information is related to the instability of membrane proteins in a detergent-solubilized state, making the growth of three-dimensional (3-D) crystals difficult. Direct observation of native membranes using the atomic force microscope (AFM) is therefore of great interest. Alternatively, two-dimensional (2-D) crystals of purified membrane proteins reconstituted in the presence of lipids provides a close to native environment and allows the structure and function of membrane proteins to be assessed. To this end, we use electron crystallography, which provides 3-D information at the atomic level. AFM allows the surface of membrane proteins to be studied at sub-nm resolution, providing information about their conformational variability that cannot be assessed by crystallographic methods. In addition, atomic force microscopy is the tool of choice to study the conformation and molecular arrangements of proteins in native membranes.