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Updated: Aug 5, 2026
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Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
Published on: October 4, 2024
Sidechain Dynamics and Allosteric Signaling in a PDZ Domain
1LSP Consulting LLC, Temecula, California 92591, United States.
The Journal of Physical Chemistry. B
|July 27, 2026
Summary
We discovered "entropy sloshing," a slow, collective drift in protein sidechain stability, revealing new insights into entropy-driven allostery and allosteric signaling mechanisms.
Area of Science:
- Biophysics
- Structural Biology
- Computational Biology
Background:
- Entropy-driven allostery involves conformational entropy redistribution in protein sidechain networks.
- The dynamic mechanisms underlying this process are not fully understood.
Purpose of the Study:
- To investigate the dynamic basis of entropy-driven allostery in the PDZ3 domain.
- To characterize the collective behavior of sidechain networks during allosteric signaling.
Main Methods:
- Local Sidechain Stability (LSP-MD) simulations were applied to four functional states of the PDZ3 domain.
- Simulations spanned 500 ns and were performed in triplicate.
- Principal component analysis was used to analyze simulation data.
Main Results:
- LSP-MD measurements converged within 10 ns.
- Sidechain stabilities exhibited a slow drift (100-200 ns), termed "entropy sloshing," an emergent collective behavior.
- Distinct signals identified included network stabilization by the α3 helix and the effect of peptide binding.
- Peptide binding demonstrated entropy-driven allosteric signaling through the sidechain network.
Conclusions:
- "Entropy sloshing" represents a novel emergent dynamic behavior in protein sidechain networks.
- Allosteric signaling, particularly peptide binding, can be effectively propagated through these networks.
- This study provides a dynamic framework for understanding entropy-driven allostery.
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