Tobias Mühlethaler, Timothy Sharpe
Size-exclusion chromatography coupled to multi-angle static light scattering measures the shape-independent molar mass of macromolecules after chromatographic separation of different-sized species in a mixture. The use of a light-scattering detector together with two detectors that measure concentration by different methods allows the molar mass of detergent-solubilized integral membrane proteins to be analyzed in detail. The method determines the total molar mass of the protein-detergent complex, the molar mass of the protein component, and the molar mass of the detergent micelle. This information allows a user to assess the oligomeric state and polydispersity of the detergent-solubilized integral membrane protein before use in structural biology or functional studies.