2005 Fiscal Year Final Research Report Summary
Protein Structural Changes Probed by Non-resonance Raman Spectroscopy
| Project/Area Number |
16570131
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
UNNO MASASHI TOKOKU UNIVERSITY, Institute of Multidisciplinary Research for Advanced Materials, Research Associate, 多元物質科学研究所, 助手 (50255428)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAUCHI Seigo Tohoku University, Institute of Multisciplinary Research for Advanced Materials, Professor, 多元物質科学研究所, 教授 (10127152)
TOKUNAGA Fumio OSAKA UNIVERSITY, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (80025452)
TOKUTOMI Sataru OSAKA PREFECTURE UNIVERSITY, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (90142009)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Raman Spectroscopy / Vibrational Spectroscopy / Photoreceptor Protein / Density Functional Theory / Signal Transduction |
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| Research Abstract |
Raman spectroscopy is a powerful technique to investigate protein dynamic structure at atomic details. Most of the Raman spectroscopic investigations use "resonance effect" to enhance the Raman signals. However, resonance Raman spectroscopy is often suffered by fluorescence from the sample. In this study, we mainly use non-resonance Raman technique to probe protein structural changes in the photoreceptor proteins.
(1) Photoactive yellow protein (PYP) is a bacterial photoreceptor containing a 4-hydroxycinnamyl chromophore. We have applied resonance and non-resonance Raman spectroscopy to investigate protein structural changes during the photocycle of PYP. We also performed normal coordinate calculations based on the density functional theory and assigned most of the vibrational modes of the chromophore
(2) Phototropin is a flavin containing blue-light photoreceptor for plants. We have measured the Raman spectra of the signaling state of phototropin for the first time. Furthermore, we performed normal coordinate calculations based on the density functional theory and assigned most of the vibrational modes of the chromophore both in the dark and signaling states.
(3) The flavin adenine dinucleotide (FAD)-binding BLUF domain constitutes a new class of blue-light receptors, and the N-terminal domain of AppA is a representative of this family. Upon light absorption, AppA undergoes a photocycle with a signaling state, which exhibits ca. 10 nm red-shift in the UV-visible absorption spectrum. We have characterized light-dependent changes in the active site of an AppA BLUF domain by Raman spectroscopy. The present study has found that altered chromophore-protein interactions, including a hydrogen bond at the C4=O position and structural changes around the N10-ribityl side chain, are a key event in this activation process.
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