Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae
<jats:p> Photosynthetic organisms use pigment–protein complexes to capture the sunlight that powers most life on earth. Within these complexes, the position of the embedded pigments is all optimized for light harvesting. At the same time, the protein scaffold undergoes thermal fluctuations tha...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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AIP Publishing
2022
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| Online Access: | https://hdl.handle.net/1721.1/145500 |
| _version_ | 1811068622275084288 |
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| author | Moya, Raymundo Norris, Audrey C Spangler, Leah C Scholes, Gregory D Schlau-Cohen, Gabriela S |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Moya, Raymundo Norris, Audrey C Spangler, Leah C Scholes, Gregory D Schlau-Cohen, Gabriela S |
| author_sort | Moya, Raymundo |
| collection | MIT |
| description | <jats:p> Photosynthetic organisms use pigment–protein complexes to capture the sunlight that powers most life on earth. Within these complexes, the position of the embedded pigments is all optimized for light harvesting. At the same time, the protein scaffold undergoes thermal fluctuations that vary the structure, and, thus, photophysics, of the complexes. While these variations are averaged out in ensemble measurements, single-molecule spectroscopy provides the ability to probe these conformational changes. We used single-molecule fluorescence spectroscopy to identify the photophysical substates reflective of distinct conformations and the associated conformational dynamics in phycoerythrin 545 (PE545), a pigment–protein complex from cryptophyte algae. Rapid switching between photophysical states was observed, indicating that ensemble measurements average over a conformational equilibrium. A highly quenched conformation was also identified, and its population increased under high light. This discovery establishes that PE545 has the characteristics to serve as a photoprotective site. Finally, unlike homologous proteins from the evolutionarily related cyanobacteria and red algae, quenching was not observed upon photobleaching, which may allow for robust photophysics without the need for rapid repair or replacement machinery. Collectively, these observations establish the presence of a rich and robust set of conformational states of PE545. Cryptophytes exhibit particularly diverse energetics owing to the variety of microenvironments in which they survive, and the conformational states and dynamics reported here may provide photophysical flexibility that contributes to their remarkable ability to flourish under diverse conditions. </jats:p> |
| first_indexed | 2024-09-23T07:58:41Z |
| format | Article |
| id | mit-1721.1/145500 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T07:58:41Z |
| publishDate | 2022 |
| publisher | AIP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1455002022-09-23T10:02:35Z Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae Moya, Raymundo Norris, Audrey C Spangler, Leah C Scholes, Gregory D Schlau-Cohen, Gabriela S Massachusetts Institute of Technology. Department of Chemistry <jats:p> Photosynthetic organisms use pigment–protein complexes to capture the sunlight that powers most life on earth. Within these complexes, the position of the embedded pigments is all optimized for light harvesting. At the same time, the protein scaffold undergoes thermal fluctuations that vary the structure, and, thus, photophysics, of the complexes. While these variations are averaged out in ensemble measurements, single-molecule spectroscopy provides the ability to probe these conformational changes. We used single-molecule fluorescence spectroscopy to identify the photophysical substates reflective of distinct conformations and the associated conformational dynamics in phycoerythrin 545 (PE545), a pigment–protein complex from cryptophyte algae. Rapid switching between photophysical states was observed, indicating that ensemble measurements average over a conformational equilibrium. A highly quenched conformation was also identified, and its population increased under high light. This discovery establishes that PE545 has the characteristics to serve as a photoprotective site. Finally, unlike homologous proteins from the evolutionarily related cyanobacteria and red algae, quenching was not observed upon photobleaching, which may allow for robust photophysics without the need for rapid repair or replacement machinery. Collectively, these observations establish the presence of a rich and robust set of conformational states of PE545. Cryptophytes exhibit particularly diverse energetics owing to the variety of microenvironments in which they survive, and the conformational states and dynamics reported here may provide photophysical flexibility that contributes to their remarkable ability to flourish under diverse conditions. </jats:p> 2022-09-19T17:41:36Z 2022-09-19T17:41:36Z 2022-07-21 2022-09-19T17:28:54Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/145500 Moya, Raymundo, Norris, Audrey C, Spangler, Leah C, Scholes, Gregory D and Schlau-Cohen, Gabriela S. 2022. "Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae." The Journal of Chemical Physics, 157 (3). en 10.1063/5.0095763 The Journal of Chemical Physics Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf AIP Publishing American Institute of Physics (AIP) |
| spellingShingle | Moya, Raymundo Norris, Audrey C Spangler, Leah C Scholes, Gregory D Schlau-Cohen, Gabriela S Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title | Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title_full | Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title_fullStr | Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title_full_unstemmed | Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title_short | Observation of conformational dynamics in single light-harvesting proteins from cryptophyte algae |
| title_sort | observation of conformational dynamics in single light harvesting proteins from cryptophyte algae |
| url | https://hdl.handle.net/1721.1/145500 |
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