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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
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High resolution approach to the native state ensemble kinetics and thermodynamics
Sangwook Wu1, Pavel I Zhuravlev, Garegin A Papoian
1Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, USA.
Biophysical Journal
|September 23, 2008
Summary
Researchers mapped the free energy surface of the Trp-cage protein to understand conformational changes. This revealed the protein
Area of Science:
- Biophysics
- Computational Biology
- Protein Dynamics
Background:
- Protein functions like allosteric switching and binding depend on conformational transitions.
- Understanding these transitions is key to molecular biology.
Purpose of the Study:
- To construct and analyze the two-dimensional free energy surface (FES) of the native basin for the Trp-cage protein.
- To investigate the kinetics and mechanisms of conformational transitions in Trp-cage.
Main Methods:
- Extensive explicit water all-atom molecular dynamics simulations.
- Construction of a two-dimensional free energy surface (FES) using native substructures as order parameters.
- Analysis of transition kinetics and comparison with a one-dimensional reaction coordinate.
Main Results:
- The conformational switching of Trp-cage exhibits borderline diffusive and weakly-activated dynamics.
- The transition kinetics are accurately described as a biexponential process.
- Explicit water simulations revealed key interactions stabilizing low-energy conformations, with notable differences from implicit water models.
Conclusions:
- The study provides insights into the conformational dynamics of globular proteins.
- Water plays a crucial role in mediating residue interactions within proteins.
- The FES approach is valuable for studying protein conformational transitions.
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