Determination of Membrane Protein Molecular Weight Using Sedimentation Equilibrium Analytical Ultracentrifugation

Both the stoichiometry and stability of native membrane protein complexes pose challenges to understanding the biology of these proteins. Sedimentation equilibrium analytical ultracentrifugation is well recognized as a thermodynamically rigorous technique for determining these quantities for macromolecules. This unit describes the experimental strategies that can be used to extract this information for membrane proteins reconstituted in vitro in detergent micelle or detergent/lipid mixed micelle solutions.