Amphiphilic zinc bacteriochlorophyll a derivatives that function as artificial energy acceptors in photosynthetic antenna complexes chlorosomes of the green sulfur photosynthetic bacterium Chlorobaculum limnaeum
| Autor: | Yoshitaka Saga, Tomohiro Miyatake, Naoya Takahashi, Hitoshi Tamiaki |
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| Rok vydání: | 2018 |
| Předmět: |
General Chemical Engineering
Supramolecular chemistry General Physics and Astronomy Chlorosome 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry Photosynthesis 01 natural sciences Fluorescence 0104 chemical sciences chemistry.chemical_compound Monomer chemistry Amphiphile Bacteriochlorophyll Photosynthetic bacteria 0210 nano-technology |
| Zdroj: | Journal of Photochemistry and Photobiology A: Chemistry. 353:612-617 |
| ISSN: | 1010-6030 |
| DOI: | 10.1016/j.jphotochem.2017.08.001 |
| Popis: | Green photosynthetic bacteria have extramembranous light-harvesting complexes called chlorosomes. Light-energy captured by bacteriochlorophyll (BChl) self-aggregates inside chlorosomes is transferred to BChl a -peptide complexes called baseplates on the chlorosome surface. We substitute the baseplate complex in chlorosomes from a green sulfur photosynthetic bacterium Chlorobaculum limnaeum with amphiphilic Zn BChl a derivatives. Zn BChl a derivatives 1 – 3 , which were esterified with polyethylene glycol (PEG) 600, PEG400, and diethylene glycol, respectively, were successfully hybridized with chlorosomes without baseplates. These derivatives in the hybridized chlorosomes emitted by predominant excitation of BChl e self-aggregates at 460 nm, indicating that they were able to accept the excitation energy from BChl e aggregates inside chlorosomes. Zn BChl a derivatives 1 and 2 emitted at 787 nm by the excitation energy transfer. In contrast, fluorescence from 3 esterified with a short hydrophilic chain, diethylene glycol, was broadened around 785 and 820 nm. The broad emission bands would consist of at least two bands, which were ascribable to the monomeric and aggregated forms. These results indicate that PEG600 and PEG400 provide appropriate amphiphilicity to Zn BChl a derivatives for dispersion in the membranous region of chlorosomes. The present study will be helpful for not only elucidation of the energy transfer mechanism in chlorosomes but also development of artificial photofunctional supramolecular complexes by hybridization of natural photosynthetic systems with synthetic molecules. |
| Databáze: | OpenAIRE |
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