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Updated: Jul 19, 2026
04:37
High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States
Published on: June 29, 2021
Electron transfer and electronic energy relaxation under high hydrostatic pressure
A Freiberg1, A Ellervee, M Tars
1Institute of Physics, Riia 142, EE2400 Tartu, Estonia. freiberg@park.tartu.ee
Biophysical Chemistry
|October 13, 2006
Summary
High hydrostatic pressure influences photoinduced electron transfer in Zn-porphyrin-pyromellitimide complexes and exciton relaxation in FMO proteins. Pressure can tune chemical reactions, while FMO protein
Area of Science:
- Photochemistry
- Biophysics
- Physical Chemistry
Background:
- Photoinduced intramolecular electron transfer and exciton relaxation are fundamental processes in chemistry and biology.
- Understanding the influence of external factors like hydrostatic pressure is crucial for controlling these phenomena.
Purpose of the Study:
- To investigate the effect of high hydrostatic pressure (up to 8 kbar) on photoinduced electron transfer in a Zn-porphyrin-pyromellitimide (ZnP-PM) complex.
- To examine the impact of pressure on exciton relaxation dynamics in the FMO protein, a photosynthetic antenna protein.
Main Methods:
- Spectrally selective picosecond time-resolved emission spectroscopy was employed.
- Measurements were conducted on ZnP-PM in toluene at room temperature and on FMO protein at low temperatures (4–100 K).
Main Results:
- Pressure significantly influences electron transfer rates in the ZnP-PM complex, with the potential to accelerate or inhibit the reaction.
- The classical nonadiabatic electron transfer theory accurately describes the ZnP-PM system under pressure.
- Pressure effects on exciton relaxation in the FMO protein were marginal, likely due to its protective protein structure.
- Protein denaturation occurred when compressed at room temperature before cooling, leading to drastic changes in spectral and dynamic properties.
Conclusions:
- External hydrostatic pressure is a sensitive tool for studying, controlling, and tuning elementary chemical reactions.
- Pressure can alter reaction pathways and rates, offering a method to manipulate chemical processes.
- The FMO protein's unique structure shields its photosynthetic pigments from external pressure effects.
- Further research is needed to elucidate the origin of slow exciton dynamics in the FMO protein.
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