| Project/Area Number |
18310150
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Living organism molecular science
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| Research Institution | The Institute of Physical and Chemical Research |
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Principal Investigator |
ATSUSHI Miywaki The Institute of Physical and Chemical Research, Cell Function dynamics, Laboratory Head (80251445)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUNO Hideaki RIKEN, Cell Function dynamics, Research Specialist (80301779)
TSUTSUI Hidekazu RIKEN, Cell Function dynamics, Visiting Researcher (30392038)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥18,310,000 (Direct Cost: ¥16,000,000、Indirect Cost: ¥2,310,000)
Fiscal Year 2007: ¥10,010,000 (Direct Cost: ¥7,700,000、Indirect Cost: ¥2,310,000)
Fiscal Year 2006: ¥8,300,000 (Direct Cost: ¥8,300,000)
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| Keywords | Fluorescent Protein / Bioimaging |
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| Research Abstract |
Understanding the molecular mechanisms of photomodulatable fluorescent proteins enables us to design photoconvertible and photochromic proteins with desirable properties.
Kaede and KikGR are fluorescent proteins that display green-to-red photoconvertibility induced by irradiation with UV or violet light. These proteins contain a His^<62>-Tyr^<63>-G1y^<64>tri-peptide sequence, which forms a green chromophore that can be photoconverted to a red one via formal β-elimination and subsequent extension of the π-conjugation. We demonstrate that the β-elimination reaction can utilize carboxamide as a leaving group, which is not typically seen in conventional β-elimination reactions.
Photochromism is defined as the reversible transformation of a single chemical species between two states having different absorption spectra induced by photoirradiation. Dronpa is a photochromic fluorescent protein engineered from a coral protein. While Dronpa normally absorbs at 503 nm and emits green fluorescence with a high fluorescence quantum yield (¢FL=0.85), strong irradiation at 488 nm can convert this protein to a non-fluorescent state that absorbs at 390 nm (dark state, denoted by DronpaD). The protein can then be switched back to the original emissive state (bright state, denoted by DronpaB) with minimal irradiation at 405 nm. Due to its reliable photochromic properties, Dronpa can be used to record, erase, or read information in a non-destructive manner. We demonstrate structural flexibility of the chromophore and a part of the β-barrel of DronpaD with NMR analyses of both DronpaB and DronpaD in solution. Given the specific characteristics of photochromism in this protein, the critical flexibility within this structure may be difficult to identify by protein crystallography at extremely low temperatures.
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