β2-Adrenergic Receptor Solutions for Structural Biology Analyzed with Microscale NMR Diffusion Measurements

摘要

Solution NMR spectra of integral membrane proteins (IMP) reconstituted in detergent micelles are obtained at high quality only over a narrow range of detergent concentrations, which emphasizes the importance of detailed characterization of IMP-containing particles that are targets for structure determination or functional studies. Thereby one has to consider that some chemicals needed to prepare stable aqueous IMP solutions may in part precipitate or aggregate during sample preparation, so that the composition of the final solutions used for structural biology may vary depending on the exact course of the sample preparation. Here we determined the composition of IMP solutions with spectroscopic techniques, and then measured the hydrodynamic properties of the mixed IMP/detergent/lipid micelles present at given solution compositions with microcoil NMR experiments, which require only microgram amounts of material and thus enable screens of a wide range of conditions.