Universal Relation between Instantaneous Diffusivity and Radius of Gyration of Proteins in Aqueous Solution

Protein conformational fluctuations are highly complex and exhibit long-term correlations. Here, molecular dynamics simulations of small proteins demonstrate that these directly affect the protein's instantaneous diffusivity $D_I$. We find radius gyration $R_g$ exhibits $1/f$ fluctuations, synchronous with Our analysis demonstrates validity local Stokes-Einstein type relation $D_I\propto1/(R_g + R_0)$, where $R_0\sim0.3$ nm is assumed to be a hydration layer around protein. From different protein types both strong weak appears general property.