Fluctuation-induced hydrodynamic coupling in an asymmetric, anisotropic dumbbell

Area of Science:

• Biophysics
• Chemical Physics
• Biochemistry

Background:

• Macromolecular complexes exhibit enhanced diffusion, particularly catalytically active enzymes.
• Internal fluctuations in these complexes can negatively contribute to their diffusion coefficient.
• The strength of subunit interactions and asymmetry influence fluctuation-induced diffusion.

Purpose of the Study:

• To develop a model analyzing the effect of anisotropy on the diffusion properties of modular structures.
• To extend a minimal model of an asymmetric dumbbell for macromolecular complexes.
• To investigate the impact of internal and external symmetry on diffusion.

Main Methods:

• Utilizing a moment expansion method.
• Deriving an analytic form for the long-time diffusion coefficient.
• Systematically analyzing the dependence on internal and external symmetry.

Main Results:

• An analytic form for the diffusion coefficient of an asymmetric, anisotropic dumbbell was derived.
• The study systematically shows the dependence of diffusion on internal and external symmetry.
• Internal fluctuations were confirmed to negatively contribute to the diffusion coefficient.

Conclusions:

• The moment expansion method provides a tractable analytical route for studying dumbbell model dynamics.
• This work facilitates a more detailed understanding of hydrodynamic interactions' effects on biomolecule diffusion.
• The findings are crucial for describing the transport properties of complex biomolecular structures.