Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy
Abstract Protein-bound water molecules are essential for the structure and function of many membrane proteins, including G-protein-coupled receptors (GPCRs). Our prior work focused on studying the primate green- (MG) and red- (MR) sensitive visual pigments using low-temperature Fourier transform inf...
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Nature Portfolio
2017-07-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-017-05177-4 |
| _version_ | 1818749373162455040 |
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| author | Kota Katayama Yuki Nonaka Kei Tsutsui Hiroo Imai Hideki Kandori |
| author_facet | Kota Katayama Yuki Nonaka Kei Tsutsui Hiroo Imai Hideki Kandori |
| author_sort | Kota Katayama |
| collection | DOAJ |
| description | Abstract Protein-bound water molecules are essential for the structure and function of many membrane proteins, including G-protein-coupled receptors (GPCRs). Our prior work focused on studying the primate green- (MG) and red- (MR) sensitive visual pigments using low-temperature Fourier transform infrared (FTIR) spectroscopy, which revealed protein-bound waters in both visual pigments. Although the internal waters are located in the vicinity of both the retinal Schiff base and retinal β-ionone ring, only the latter showed differences between MG and MR, which suggests their role in color tuning. Here, we report FTIR spectra of primate blue-sensitive pigment (MB) in the entire mid-IR region, which reveal the presence of internal waters that possess unique water vibrational signals that are reminiscent of a water cluster. These vibrational signals of the waters are influenced by mutations at position Glu113 and Trp265 in Rh, which suggest that these waters are situated between these two residues. Because Tyr265 is the key residue for achieving the spectral blue-shift in λmax of MB, we propose that these waters are responsible for the increase in polarity toward the retinal Schiff base, which leads to the localization of the positive charge in the Schiff base and consequently causes the blue-shift of λmax. |
| first_indexed | 2024-12-18T04:02:45Z |
| format | Article |
| id | doaj.art-2eccd9a414a540d2a63ffd2a3bd85d9d |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-18T04:02:45Z |
| publishDate | 2017-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-2eccd9a414a540d2a63ffd2a3bd85d9d2022-12-21T21:21:39ZengNature PortfolioScientific Reports2045-23222017-07-017111010.1038/s41598-017-05177-4Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR SpectroscopyKota Katayama0Yuki Nonaka1Kei Tsutsui2Hiroo Imai3Hideki Kandori4Department of Life Science and Applied Chemistry, Nagoya Institute of TechnologyDepartment of Life Science and Applied Chemistry, Nagoya Institute of TechnologyPrimate Research Institute, Kyoto UniversityPrimate Research Institute, Kyoto UniversityDepartment of Life Science and Applied Chemistry, Nagoya Institute of TechnologyAbstract Protein-bound water molecules are essential for the structure and function of many membrane proteins, including G-protein-coupled receptors (GPCRs). Our prior work focused on studying the primate green- (MG) and red- (MR) sensitive visual pigments using low-temperature Fourier transform infrared (FTIR) spectroscopy, which revealed protein-bound waters in both visual pigments. Although the internal waters are located in the vicinity of both the retinal Schiff base and retinal β-ionone ring, only the latter showed differences between MG and MR, which suggests their role in color tuning. Here, we report FTIR spectra of primate blue-sensitive pigment (MB) in the entire mid-IR region, which reveal the presence of internal waters that possess unique water vibrational signals that are reminiscent of a water cluster. These vibrational signals of the waters are influenced by mutations at position Glu113 and Trp265 in Rh, which suggest that these waters are situated between these two residues. Because Tyr265 is the key residue for achieving the spectral blue-shift in λmax of MB, we propose that these waters are responsible for the increase in polarity toward the retinal Schiff base, which leads to the localization of the positive charge in the Schiff base and consequently causes the blue-shift of λmax.https://doi.org/10.1038/s41598-017-05177-4 |
| spellingShingle | Kota Katayama Yuki Nonaka Kei Tsutsui Hiroo Imai Hideki Kandori Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy Scientific Reports |
| title | Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy |
| title_full | Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy |
| title_fullStr | Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy |
| title_full_unstemmed | Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy |
| title_short | Spectral Tuning Mechanism of Primate Blue-sensitive Visual Pigment Elucidated by FTIR Spectroscopy |
| title_sort | spectral tuning mechanism of primate blue sensitive visual pigment elucidated by ftir spectroscopy |
| url | https://doi.org/10.1038/s41598-017-05177-4 |
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