2002 Fiscal Year Final Research Report Summary
Why do the ultrafast and highly efficient pbotoreactions take place peculiarly in the protein nanospaces?
| Project/Area Number |
13640519
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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 |
Physical chemistry
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| Research Institution | Institute for Laser Technology |
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Principal Investigator |
MALAGA Noboru Institute for Laser Technology , Research Team leader, レーザーバイオ科学研究チーム, チームリーダー (30029368)
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| Co-Investigator(Kenkyū-buntansha) |
SHICHIDA Yoshinori Graduate School of Science, Kyoto Univ., Professor, 理学研究科, 教授 (60127090)
TANIGUCHI Seiji Institute for Laser Technology , Research worker, レーザーバイオ科学研究チーム, 研究員 (00342725)
CHOSROWJAN Haik Institute for Laser Technology , Research worker, レーザーバイオ科学研究チーム, 研究員 (70291036)
TANAKA Fumio Mie Prefectural College of Nursing, Professor, 看護学部, 教授 (20022907)
IMAMOTO Yasushi Graduate School of Material Science, Nara Inst. Sci. Tech. Assoc, Professor, 物質創成科学研究科, 助教授 (80263200)
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| Project Period (FY) |
2001 – 2002
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| Keywords | PYP and Rh / FP / Protein Environment / Coherent Vibration / Coherent Reaction / Ultrafast Twisting / Ultra fast Electron Transfer / Ultrafast Dynamic Stokes Shift |
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| Research Abstract |
Some photobiological systems often show barrierless or coherent ultrafast and highly efficient primary reaction processes. However, the most fundamental mechanisms realizing such superb photoreaction processes are not clear. From such a viewpoint, we are developing pioneering investigations on the ultrafast primary processes of photoreactions of some photoresponsive or photoactive proteins such as PYP, Rh and FP by means of fs fluorescence dynamics measurements. Consequently, we have demonstrated that the effect of the protein environment (protein nanospace, PNS) on such reactions of the excited chromophore as the trans-cis isomerization and electron transfer is extremely important. Furthermore, we have improved the time-resolution of our fs fluorescence up-conversion apparatus by receiving the grants-in-aid for scientific research. On the basis of the measurements with improved time-resolution, the following results have been established. l.The possibility that the ultrafast photoreac
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tions of PYP, Rh and FP are taking place from the vibrationally unrelaxed state immediately after conversion from excited Franck-Condon state to fluorescence (FI) state is further Supported. 2. In relation to this problem of the vibrationally unrelaxed Fl state and the coupling of the coherent vibrations with the twisting reaction, we have recognized faster initial decay of the Fl intensity on both blue and red edges of the Fl spectrum. These results suggest rather strongly the possible observation of the coherent vibrations in the Fl decay dynamics. Actually, by the measurements with improved time-resolutions, we have observed for the first time the coherent vibrations in the fluorescence decay curve of w.-t. PYP and PYP mutants. 3. We have observed also faster initial decay of the Fl intensity on both blue and red edged of the Fl spectrum in the case of Rh. 4. Furthermore, we have found for PYP Analogue with replaced chromophore, ultra fast dynamic Stokes shift of fluorescence rather than the quenching due to twisting and coherent vibrations coupled with fluorescence decay, indicating the importance of chromophore-PNS fine adjustment for the ultrafast twisting. Less
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Research Products
(12 results)
