ABSTRACT
Fundamental biological processes such as intercellular commu-
nication, molecular transport, signal transduction, and energy
conversion are performed by membrane proteins. These important
proteins are best studied in their native environment, the lipid
bilayer. The capability of the atomic force microscope (AFM) to
analyze samples that are in an aqueous state makes this device ideal
for use in determining the native surface structure, supramolecular
organization, conformational changes, and dynamics of membrane-
embedded proteins under near-physiological conditions. Equally
important is the fact that membrane proteins can be imaged
at nanometer resolution and at the single-molecule level with
AFM, as was explicitly explained with AFM studies of the subunit
organization of membrane receptors in chapter 11. This chapter
focuses on how AFM techniques have been utilized to study
membrane protein dynamics in solution with a view to gaining a
better understanding of the conformational changes of receptors
and ion pumps.
