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Updated: Aug 11, 2026
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Examining the Conformational Dynamics of Membrane Proteins in situ with Site-directed Fluorescence Labeling
Published on: May 29, 2011
Dynamical transition and proteinquake in photoactive yellow protein
1Department of Complex Systems Science, Graduate School of Information Science, Nagoya University, Nagoya 464-8601, Japan. kazuhito@info.human.nagoya-u.ac.jp
Summary
Protein dynamics involve motions across various timescales. A new model for photoactive yellow protein reveals how large conformational changes, like proteinquakes, coupled with smaller motions, control its photocycle and function.
Area of Science:
- Biophysics
- Structural Biology
- Protein Dynamics
Background:
- Protein functioning relies on conformational dynamics spanning nanoseconds to milliseconds.
- Understanding the interplay of these motions is crucial for deciphering protein mechanisms.
Purpose of the Study:
- To propose a model explaining the cooperative coupling of motions across different timescales in protein functioning.
- To elucidate the mechanism behind the photocycle of photoactive yellow protein.
Main Methods:
- Development of a theoretical model.
- Analysis of experimental results on photoactive yellow protein's photocycle.
Main Results:
- The model demonstrates cooperative coupling between fast and slow protein motions.
- Global collective motion, initiated by N-terminal domain unfolding, loosens chromophore packing.
- This creates a favorable environment for the photoexcited chromophore, stabilizing intermediates.
Conclusions:
- Proteinquakes, triggered by local disturbances, are key to controlling protein functioning kinetics.
- Cooperative dynamics across timescales are essential for efficient protein operation.
- The proposed model consistently explains experimental observations of photoactive yellow protein.
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