モリブデン・ヒドロキシラゼのモデルにおけるcis-MoOSユニットの電子構造の説明
Christian J Doonan1, Nick D Rubie, Katrina Peariso
1The Department of Chemistry and Biological Chemistry, The University of New Mexico, MSC03 20601 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA.
Journal of the American Chemical Society
|December 8, 2007
まとめ
モリブデン・ヒドロキシラゼは,酸素移転のためにユニークなcis-MoOSサイトを使用します. 新しいモデルは,Mo-S結合と基質酸化のための酵素機構に影響を与える非局所化されたリドックス軌道を示しています.
科学分野:
- バイオ・オーガニック化学 バイオ・オーガニック化学
- 酵素のメカニズム
- 有機金属化学 有機金属化学
背景:
- モリブデン・ヒドロキシラーゼは,酸化反応を触媒する重要な酵素である.
- 彼らは,製品組み込みのための酸素源として水を使用しています.
- アクティブサイトの電子構造を理解することは,その機能の鍵です.
研究 の 目的:
- 新しいモデル化合物におけるシス-モリブデン-オクソ-硫化物 (MoOS) 単位の電子構造を調査する.
- モリブデン水酸化酵素メカニズムにおけるこれらの電子構造の役割を明らかにする.
- 顕微鏡および計算データを酵素機能と相関させるため.
主な方法:
- 新しいモリブデンヒドロキシラーゼモデル化合物の合成:CoCp2[TpiPrMoVOS (OPh) ]とTpiPrMoVIOS (OPh).
- S K-エッジX線吸収と振動スペクトロスコピーを含むスペクトロスコピク分析.
- 詳細な結合と電子構造の計算.
主要な成果:
- Mo=S pi* LUMOの高度にデロカライズされた酸化還元軌道と,重要な硫化物リガンド特性を特定する.
- 振動スペクトロスコーピーによるリドックス状態によるMo-Sulfido結合順序変化の定量化.
- レドックス活性分子軌道がMoOS結合と硫化リガンド特性に著しく影響することを実証.
結論:
- cis-MoOSサイトの電子構造は酸化還元活性であり,酵素機構を制御する.
- MoOSサイトのユニークなエレクトロニクスによって駆動される軌道制御は,基板の酸化を制御します.
- 酸化した酵素部位は,おそらく基板を二極化し,電子シンクとして作用します.
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