| Project/Area Number |
17550123
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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 |
Functional materials chemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KINBARA Kazushi The University of Tokyo, School of Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (30282578)
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| Co-Investigator(Kenkyū-buntansha) |
TSUMOTO Kohei The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 新領域創成科学研究科, 助教授 (90271866)
TAGUCHI Hideki The University of Tokyo, Graduate School of Frontier Sciences, Associate Professor, 新領域創成科学研究科, 助教授 (40272710)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Chaperonin / Molecular Chaperon / Photochromic Molecule / Azobenzene / GFP / AND Logic Gate / 分子機械 / 光異性化 / GroEL / リフォールディング |
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| Research Abstract |
GroEL, originating from E.coli, is a tubular protein assembly consisting of fourteen subunits (57 kDa). Each seven subunits from a ring, which is stacked to form a double-decker architecture. This cylindrical assembly possesses a cavity with diameter of 4.5 nm, hight of 14.7 nm, and a wall thickness of 4.6 nm. Essentially, GroEL works as a molecular chaperon assisting folding of denatured and newly synthesized proteins by taking them into its cylindrical cavity. This process usually requires not only ATP as a fuel but also cochaperon GroES. In the absence of GroES, GroEL only traps the unfolded proteins, and simply release them without refolding by addition of ATP. It has been already reported that such guest trapping-releasing property of GroEL could be applied for manipulation of semiconductor nanoparticles.
Semibiological molecular machine with an implemented "AND" logic gate was developed with engineered chaparonin GroEL, which was capable of controlling the folding process of protein in response to ATP and light as input stimuli. The molecular design made use of a genetically engineered chaperonin GroEL bearing, at the both entrance parts of its cylindrical cavity, cystein residues, which were functionalized by an azobenzene derivative to construct photoresponsive mechanical gates (azo-GraEL). This engineered chaperonin trapped denatured green fluorescent protein (GFPdenat) and prohibited its refolding. However, when hosting azo-GroEL detected ATP (input stimulus) and UV light (input stimulus 2) at the same time, it quickly release GFPdenat to allow its refolding. In contrast, reception of either the input stimulus 1 or 2 resulted in only very slow or no substantial refolding of GFPdenat. Implementation of such "AND" logic gate mechanically drive biomolecular systems is an important step toward the development of secured drug deliver systems.
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