FRETベースのセンサーは,ATPの水解によって引き起こされる大きな形状の変化と,分子モーターミオシンの3つの異なる状態を明らかにします
W M Shih1, Z Gryczynski, J R Lakowicz
1Department of Biochemistry, Stanford University School of Medicine, California 94305, USA.
Cell
|September 28, 2000
まとめ
分子ミオシンモーターは,その光鎖結合領域で大きな角度変化を経験し,二つの異なるプレストローク状態を明らかにします. これらの状態は,結合したマグネシウム-アデノシン二酸化リン酸-リン酸 (Mg.ADP.Pi) によって誘発され,マグネシウム-アデノシン三酸化リン酸 (Mg.ATP) によって誘発されません.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
背景:
- 分子モーターであるミオシンは,細胞の動きに不可欠です.
- ミオシンの提案されたメカニズムは,アクチン相互作用中に,その軽鎖結合領域の大きな角度の振動を伴う.
- 以前のダイナミック測定では,この提案された大きな角度変化を完全に捉えることができませんでした.
研究 の 目的:
- ミオシンの軽鎖結合領域の核酸依存の角度変化を直接測定するために.
- ミオシンの機能サイクル中の構成状態を調査する.
- ミオシンの脳卒中前の状態におけるヌクレオチド結合の役割を明確にするために.
主な方法:
- 特定のラベリングサイトを作成するためにシステインのエンジニアリング.
- 高解像度フォースター共振エネルギー転送 (FRET) ベースのセンサーの開発.
- 安定状態と時間解析のFRET測定の組み合わせ.
主要な成果:
- ライトチェーン結合領域で,約70度程度の核酸依存の大きな角度変化が検出されました.
- 2つの異なるミオシン前脳卒中状態が予想外に明らかになった.
- 結合されたMg.ADP.Piは,Mg.ATPよりも,これらの脳卒中前の状態を誘発することが判明しました.
結論:
- ミオシンは重要な形状の変化を経験し,提案された大きな角の動きを検証します.
- ミオシンの脳卒中前の状態は,Mg.ADP.Pi.Piの存在によって調節されます.
- この発見は,ミオシン運動機能とヌクレオチド相互作用のメカニズムに関する新しい洞察を提供します.
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