非線形弾力性と,ミオフィラメントの単一のミオシン分子の8nmの動作ストローク

Motoshi Kaya¹, Hideo Higuchi

¹Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyou-ku, Tokyo, 113-0033 Japan.

Science (New York, N.Y.)

|August 7, 2010

まとめ

骨格のミオシン

科学分野:

バイオフィジックス生物物理学
筋肉生理学筋肉生理学

背景:

骨格筋の収縮には,ミオシン運動タンパク質がアクチン繊維と相互作用する.
ミオシンのメカニズムを理解することは,筋肉の機能と機能不全を明らかにするために不可欠です.

研究の目的:

筋肉の収縮を模倣した条件下で,単一の骨格ミオシンのステップサイズと硬さを測定するために.
ミオシンのストレンス,硬さ,および力発生の間の関係を調査するために.

主な方法:

光学トラッピングと光成像技術を使用した.
アクチン繊維とミオシン棒共同繊維と相互作用する単一の骨格ミオシンを研究した.

主要な成果:

マイオシンの硬さは,マイナスのストレスの下では,プラスのストレスの下では,マイオシンのサブフラグメント2棒ドメインの曲折に起因する,プラスのストレスの下では著しく低い.
負の緊張したミオシンの硬さの減少は,負荷の収縮時に引きずりを最小限にします.
顕在のステップサイズは,ミオシンの弾性部分の伸縮により負荷が増加するにつれて減少しますが,作業ストロックは約8ナノメートルで一定です.

結論:

ミオシンの非線形弾性性は,ミオシンの内部構造の変化と生理学的力発生の間の関係を理解するために重要である.
ミオシンの弾性特性を考慮することは,筋肉の収縮とフィラメントの滑り方の正確なモデルに不可欠です.

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