| Project/Area Number |
02102009
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| Research Category |
Grant-in-Aid for Specially Promoted Research
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| Allocation Type | Single-year Grants |
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| Research Institution | The University of Tokyo |
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Principal Investigator |
WAKABAYASHI Takeyuki Univ.of Tokyo, School of Science, Professor, 大学院・理学系研究科, 教授 (90011717)
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| Co-Investigator(Kenkyū-buntansha) |
SUTOH Kazuo Univ.of Tokyo, College of Arts and Science, Associate Professor, 教養学部, 助教授 (20111453)
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| Project Period (FY) |
1990 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥201,900,000 (Direct Cost: ¥201,900,000)
Fiscal Year 1993: ¥13,000,000 (Direct Cost: ¥13,000,000)
Fiscal Year 1992: ¥20,900,000 (Direct Cost: ¥20,900,000)
Fiscal Year 1991: ¥58,000,000 (Direct Cost: ¥58,000,000)
Fiscal Year 1990: ¥110,000,000 (Direct Cost: ¥110,000,000)
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| Keywords | Muscle / Myosin / Actin / Tubulin / Kinesin / Electron microscopy / X-ray scattering / Site-directed mutagenesis / 収縮 / 三次元像再構成 / 遺伝子改変 / 滑り運動 / 筋収縮機構 / 筋収縮蛋白 / 生物物理学 / 三次元像再開成 / 超微細構造 / 蛋白質工学 / クライオ電子顕微鏡 / 重原子標識 / 筋肉収縮 / 三次元像再構成法 / 部位特異的標識 |
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| Research Abstract |
Our goal is to understand the molecular mechanism of motor proteins on the basis of atomic structure of proteins.
First we developed new techniques for electron microscopy. Using one of new techniques we developed, that is, the site-directed heavy atom labelling electron microscopy (SHALEM), we decided the position of the 5^<th> amino acid of myosin only by electron microscopy. Also, we reconstructed three-dimensional structure of muscle during isometric contraction.
Second, we detected the structural change of myosin during ATP hyrdrolysis by electron microscopy, small angle X-ray scattering, and crystallography using X-ray diffraction. This is the first observation of detection of myosin structural change during ATP hydrolysis.
Third, we observed the structural change of thin filaments in the addition of Ca ions by cryo-electron microscopy.
Last, we found the myosin-actin interaction sites on the subdomain-1 of actin using protein engineering techniques. Also we found the motor domain of myosin. This part is essential for sliding movement of actin and production of force. Furthermore, we use protein engineering to produce the mutant actins, which activate myosin ATPase in a highly cooperative manner. We found that the replacement of only 3 amino acid residues cause the high cooperativity in Ca^<2+>-induced activation of ATPase. This region is also one of the binding sites of tropomyosin in the presence of Ca.
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