呼吸器複合体IのNADH/FMN部位における陽子結合電子移転のエネルギーと動力学
Patricia Saura1, Ville R I Kaila1
1Department of Chemistry , Technical University of Munich (TUM) , Lichtenbergstrasse 4 , Garching D-85747 , Germany.
Journal of the American Chemical Society
|March 16, 2019
まとめ
複合体Iは,陽子結合電子移転反応 (PCET) を通して有酸素呼吸を開始する. この研究は,協調した水素原子と電子移転機構を明らかにし,複合体Iにおけるコファクター相互作用とNAD+結合を説明している.
科学分野:
- 生物化学
- 分子生物学
- バイオエネルギー
背景:
- コンプレックスIはエアロビック呼吸連鎖における重要な酵素で,電子の移転と陽子のポンプを開始します.
- 複合体IにおけるNADHとFMN共因子間のプロトン結合電子伝達 (PCET) の正確なメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- 複合体IにおけるNADH駆動PCET反応のエネルギーとダイナミクスを解明する.
- 複合体Iにおける電子移転の開始のためのメカニズムモデルを提案する.
主な方法:
- 大規模密度関数理論 (DFT) の計算.
- 量子/古典モデルと原子分子ダイナミクスシミュレーションを組み合わせた.
主要な成果:
- NADH駆動のPCET反応は,ニコチナミドアデニン・ディヌクレオチド (NADH) とフラビン・モノヌクレオチド (FMN) の間の電子移転 (eT) と結合した協調された水素原子移転を含む.
- バクテリアの複合体IにおけるN1a FeSセンターの減少は酸化されたNAD+結合を強化し,潜在的に反応性酸素種の形成を防ぐ.
- 保存されたグルタミン酸残基への陽子の移転は,その後の電子移転を促進し,NADH結合を調節する.
結論:
- 複合体IにおけるNADH駆動PCET反応の詳細なメカニズムモデルが提案されている.
- この発見は 複合体I内の複雑な電子と陽子の伝達経路に光を当てました
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