Jakob Schluttig, Christian B. Korn, and Ulrich S. Schwarz

Role of anisotropy for protein-protein encounter

Phys. Rev. E 81, 030902(R) (2010)

Protein-protein interactions comprise both transport and reaction
steps. During the transport step, anisotropy of proteins and their
complexes is important both for hydrodynamic diffusion and
accessibility of the binding site. Using a Brownian dynamics approach
and extensive computer simulations, we quantify the effect of
anisotropy on the encounter rate of ellipsoidal particles covered with
spherical encounter patches. We show that the encounter rate k depends
on the aspect ratios ξ mainly through steric effects, while
anisotropic diffusion has only a little effect. Calculating
analytically the crossover times from anisotropic to isotropic
diffusion in three dimensions, we find that they are much smaller than
typical protein encounter times, in agreement with our numerical
results.