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