Translational and rotational diffusion of a small globular protein under crowded conditions.

ABSTRACT: Protein-protein interaction is the fundamental step of biological signal transduction. Interacting proteins find each other by diffusion. To gain insight into diffusion under the crowded conditions found in cells, we used nuclear magnetic resonance spectroscopy (NMR) to measure the effects of solvent additives on the translational and rotational diffusion of the 7.4 kDa globular protein, chymotrypsin inhibitor 2. The additives were glycerol and the macromolecular crowding agent, polyvinyl pyrrolidone (PVP). Both translational diffusion and rotational diffusion decrease with increasing solution viscosity. For glycerol, the decrease obeys the Stokes-Einstein and Stokes-Einstein Debye laws. Three types of deviation are observed for PVP: the decrease in diffusion with increased viscosity is le

SUBMITTER: Li C 

PROVIDER: S-EPMC2774775 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature