Protein Dynamics Preceding Photoisomerization of the Retinal Chromophore in Bacteriorhodopsin Revealed by Deep-UV Femtosecond Stimulated Raman Spectroscopy
| Autor: | Shinya Tahara, Tahei Tahara, Hikaru Kuramochi, Satoshi Takeuchi |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
inorganic chemicals
genetic structures Photoisomerization Protein Conformation Ultraviolet Rays 02 engineering and technology Spectrum Analysis Raman 010402 general chemistry Photochemistry 01 natural sciences Retina Protein structure General Materials Science Physical and Theoretical Chemistry Coloring Agents skin and connective tissue diseases biology Chemistry Tryptophan Photoreceptor protein Stereoisomerism Bacteriorhodopsin Chromophore Photochemical Processes 021001 nanoscience & nanotechnology 0104 chemical sciences Photoexcitation Kinetics Bacteriorhodopsins Femtosecond biology.protein Tyrosine sense organs 0210 nano-technology Isomerization |
| Zdroj: | The Journal of Physical Chemistry Letters. 10:5422-5427 |
| ISSN: | 1948-7185 |
| Popis: | Bacteriorhodopsin is a prototypical photoreceptor protein that functions as a light-driven proton pump. The retinal chromophore of bacteriorhodopsin undergoes C13═C14 trans-to-cis isomerization upon photoexcitation, and it has been believed to be the first event that triggers the cascaded structural changes in bacteriorhodopsin. We investigated the protein dynamics of bacteriorhodopsin using deep-ultraviolet resonance femtosecond stimulated Raman spectroscopy. It was found that the stimulated Raman signals of tryptophan and tyrosine residues exhibit significant changes within 0.2 ps after photoexcitation while they do not noticeably change during the isomerization process. This result implies that the protein environment changes first, and its change is small during isomerization. The obtained femtosecond stimulated Raman data indicate that ultrafast change is induced in the protein part by the sudden creation of the large dipole of the excited-state chromophore, providing an environment that realizes efficient and selective isomerization. |
| Databáze: | OpenAIRE |
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