Intramolecular signaling pathways revealed by modeling anisotropic thermal diffusion

Area of Science:

• Computational Biology
• Biophysics
• Structural Biology

Background:

• Allosteric communication relies on rapid, long-range conformational changes within proteins.
• Understanding these intramolecular signaling pathways is crucial for deciphering protein function.

Purpose of the Study:

• To introduce and validate a novel non-equilibrium molecular dynamics simulation method, anisotropic thermal diffusion (ATD).
• To observe and characterize dominant intramolecular signaling pathways in proteins, specifically focusing on PSD-95.

Main Methods:

• Developed and applied anisotropic thermal diffusion (ATD), a non-equilibrium molecular dynamics simulation technique.
• Simulated the protein PSD-95, a member of the PDZ domain protein family.
• Compared ATD method's performance against conventional solution molecular dynamics methods.

Main Results:

• Successfully observed a dominant intramolecular signaling pathway in PSD-95 using ATD.
• The ATD method demonstrated significantly enhanced signal-to-noise ratio compared to conventional methods.
• The identified pathway aligns well with predictions from extensive multiple sequence analysis of PDZ domains.

Conclusions:

• The ATD method provides a powerful and efficient approach for visualizing long-distance correlations and intramolecular signaling pathways.
• ATD overcomes limitations of conventional methods by requiring fewer homologous proteins and shorter simulation times.
• This technique serves as a valuable complement to experimental studies for elucidating the physical basis of intramolecular signaling.