Minute Additions of DMSO Affect Protein Dynamics Measurements by NMR Relaxation Experiments through Significant Changes in Solvent Viscosity.

ABSTRACT: Studies of protein-ligand binding often rely on dissolving the ligand in dimethyl sulfoxide (DMSO) to achieve sufficient solubility, and then titrating the ligand solution into the protein solution. As a result, the final protein-ligand solution contains small amounts of DMSO in the buffer. Here we report how the addition of DMSO impacts studies of protein conformational dynamics. We used ¹⁵ N NMR relaxation to compare the rotational diffusion correlation time (τ_C ) of proteins in aqueous buffer with and without DMSO. We found that τ_C scales with the viscosity of the water-DMSO mixture, which depends sensitively on the amount of DMSO and varies by a factor of 2 across the relevant concentration range. NMR relaxation studies of side chains dynamics are commo

SUBMITTER: Wallerstein J 

PROVIDER: S-EPMC6391962 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature