ATP合成酵素 (F0F1) のcサブユニットオリゴマーの機械的な回転:直接観察
1Division of Biological Sciences, Institute of Scientific and Industrial Research, Osaka University, CREST (Core Research for Evolutional Science and Technology) of Japan Science and Technology Corporation, Ibaraki, Osaka 567-0047, Japan.
Science (New York, N.Y.)
|November 27, 1999
まとめ
F0F1酵素はATPの水解を使用して,F1モーターと同じようなトルクを生成します. これは,F0およびF1サブユニットのカップリングされた回転が,ATP合成および水解におけるエネルギー変換に不可欠であることを示唆しています.
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.
- バイオエネルギー学 バイオエネルギー学
背景:
- F0F1は,ミトコンドリアとバクテリアの膜に存在する酵素複合体です.
- 陽子グラデーションを使用してアデノシン5'-トリフォスファート (ATP) を合成し,ATPを水分解してグラデーションを作成します.
- 複合カップルはF0を通って陽子輸送を行い,F1ではATP合成/水解を行います.
研究 の 目的:
- ATPの水解中にF0サブユニットの回転力学を調査する.
- F0cサブユニットオリゴーマーとF1ガンマサブユニットによって生成されたトルクを比較する.
- エネルギー伝導における結合回転の役割を明らかにする.
主な方法:
- F0 c亜単位オリゴーマーに結合したアクチンフィラメントの回転を測定するための実験装置が考案されました.
- 回転のエネルギー源はATPの水解でした.
- ロータリートルクは,生体物理学的技術を用いて定量化されました.
主要な成果:
- ATPの水解で回転したF0c亜単位のオリゴーマーに結合したアクチン線維.
- cサブユニットオリゴマーの測定された回転トルクは,約40ピコニュートンナノメートルでした.
- このトルク値は,F1モーターのガンマサブユニットによって生成されるトルクに匹敵します.
結論:
- F0F1のガンマとcサブユニットは,ATPの水解と合成の間に一致して回転する可能性があります.
- F0およびF1コンポーネント間のカップリングされた回転は,エネルギーカップリングの重要なメカニズムとして提案されています.
- このメカニズムは,陽子輸送とATPの回転の間のリンクを容易にする.
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