Evaluating rotation diffusion properties of molecules from short trajectories

Area of Science:

• Computational Biology
• Biophysics
• Protein Dynamics

Background:

• Understanding protein rotational diffusion is crucial for characterizing molecular motion and function.
• Traditional methods for determining the rotational diffusion tensor require extensive molecular dynamics (MD) simulations.
• Short MD trajectories often lack sufficient data for accurate analysis of rotational dynamics.

Purpose of the Study:

• To develop and validate a method for precisely estimating protein rotational diffusion tensor values from short molecular dynamics trajectories.
• To provide a more computationally efficient approach for analyzing protein rotational dynamics.
• To compare the results with existing hydrodynamic models and experimental data.

Main Methods:

• Analysis of global angular momentum autocorrelation functions from short MD trajectories (2-3 ns).
• Application of the protocol to various model systems including peptides and proteins (e.g., GB3, BPTI, LYS, PB1, thrombin).
• Complementary analysis to standard methods relying on rotational autocorrelation functions.

Main Results:

• Accurate estimation of principal values of the rotational diffusion tensor is achievable with short trajectories.
• The global angular momentum approach provides reliable results, outperforming traditional methods in terms of simulation time.
• The method was successfully applied to diverse protein systems, showing good agreement with predictions and experimental data.

Conclusions:

• Short molecular dynamics trajectories, when analyzed using global angular momentum autocorrelation functions, are sufficient for precise rotational diffusion tensor estimation.
• This method offers a significant advancement in computational efficiency for studying protein dynamics.
• The validated protocol can be widely applied to various proteins and peptides for structural and functional insights.