マルチコッパー酸化塩基におけるタイプ3ペアの2電子還元対1電子酸化

Christian H Kjaergaard¹, Stephen M Jones¹, Sébastien Gounel²

¹†Department of Chemistry, Stanford University, Stanford, California 94305, United States.

Journal of the American Chemical Society

|June 16, 2015

まとめ

マルチコッパーオキシダゼ (MCOs) は O2.2 を減らすために三核銅クラスタを使用します. 休息中の酸化 (RO) 形態は

科学分野:

バイオケミストリーバイオケミストリー
バイオ・オーガニック化学バイオ・オーガニック化学

背景:

マルチコッパー酸化酶 (MCOs) は,三核銅集群 (TNC) を使用して,O2をH2Oに還元することを触媒化します.
休息形態は2種類あり,代替休息 (AR) と酸化休息 (RO) である.
高電位電子ドナーは,MCOs内のすべての銅部位を減少させることができます.

研究の目的:

高ポテンシャルMCOのRO形態の還元メカニズムを研究する.
T1銅部位がT3双核銅部位を減少させる役割を解説する.
MCOの還元活性化中にメタステーブル状態の形成を理解する.

主な方法:

MCOのスペクトロスコープによる評価.
密度関数理論 (DFT) による計算.
トNC内の電子伝送経路の分析.

主要な成果:

RO形態のT3双核銅部位は,T1銅部位を通じて還元可能である.
還元は2電子プロセスを経て進行し,メタステーブルな半減T3状態を形成します.
還元されたT3部位の酸化により,熱力学的に好ましいAR形態が生成されます.
DFTの計算は,活性部位調節におけるタンパク質の骨格の役割を強調しています.

結論:

高ポテンシャルMCOのRO形式は,T3サイトのユニークな2電子の減少を経験します.
メタステーブルな半減T3状態は,完全な還元活性化に不可欠です.
タンパク質の構造は,銅の酸化還元状態と触媒活性化を積極的に制御する.

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