Association of Biomolecular Systems via Pulsed Field Gradient NMR Self-Diffusion Measurements

摘要

Most biochemical interactions involve translational or rotational diffusion of molecules. Self-diffusion is defined as translational motion reflecting the random motions of a molecule in the absence of a concentration gradient. The coefficient of this motion, D_s, is indicative of hydrodynamic properties and molecular size. Numerous proteins are now recognized to depend on oligomerization for biological activity or receptor binding, such as the dimerization of signal transduction proteins including cytokines and SH2 and SH3 domains. Currently, many of these systems are the target of solution-structure determination by NMR. Because of the difficulty and importance of assigning long-range distances in NMR structure determination studies, it is necessary to know the oligomeric state of a biomolecular system prior to structure calculations using NMR data.