Mechanisms Underlying Carotenoid Absorption in Oxygenic Photosynthetic Proteins
| Autor: | Bruno Robert, Alison Telfer, Maria M. Mendes-Pinto, Denise Galzerano, Cristian Ilioaia, Andrew A. Pascal |
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| Rok vydání: | 2013 |
| Předmět: |
Light
Photosystem II Protein Conformation Light-Harvesting Protein Complexes Plasma protein binding Electronic structure Bioenergetics Biology Spectrum Analysis Raman 010402 general chemistry Photosynthesis Photosystem I 01 natural sciences Biochemistry Light-harvesting complex 03 medical and health sciences Protein structure Spinacia oleracea Molecular Biology Carotenoid 030304 developmental biology chemistry.chemical_classification 0303 health sciences Lutein Temperature Photosystem II Protein Complex food and beverages Cell Biology beta Carotene 3. Good health 0104 chemical sciences chemistry Solvents Spectrophotometry Ultraviolet Protein Binding |
| Zdroj: | Journal of Biological Chemistry |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112.423681 |
| Popis: | The electronic properties of carotenoid molecules underlie their multiple functions throughout biology, and tuning of these properties by their in vivo locus is of vital importance in a number of cases. This is exemplified by photosynthetic carotenoids, which perform both light-harvesting and photoprotective roles essential to the photosynthetic process. However, despite a large number of scientific studies performed in this field, the mechanism(s) used to modulate the electronic properties of carotenoids remain elusive. We have chosen two specific cases, the two β-carotene molecules in photosystem II reaction centers and the two luteins in the major photosystem II light-harvesting complex, to investigate how such a tuning of their electronic structure may occur. Indeed, in each case, identical molecular species in the same protein are seen to exhibit different electronic properties (most notably, shifted absorption peaks). We assess which molecular parameters are responsible for this in vivo tuning process and attempt to assign it to specific molecular events imposed by their binding pockets. Background: Tuning of carotenoid function, through modulation of their electronic properties, is seen throughout Nature. Results: Two photosynthetic proteins are able to modulate the effective conjugation length of bound carotenoid cofactors. Conclusion: Altering the conformation of conjugated end cycles via steric hindrance provides a means of tuning the electronic properties of carotenoids. Significance: A novel mechanism tuning the functional properties of carotenoids is revealed. |
| Databáze: | OpenAIRE |
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