クラスIのリボヌクレオチド還元酵素と関連する双核非ヘム鉄酵素のペロキソ型中間物質
Kasper P Jensen1, Caleb B Bell, Michael D Clay
1DTU-Chemistry, Technical University of Denmark, Building 207, DK 2800 Kgs. Lyngby, Denmark.
Journal of the American Chemical Society
|August 12, 2009
まとめ
計算化学は,水または陽子が,非ヘム二鉄リボヌクレオチド還元酵素におけるペロキソ中間物質を活性化する方法を示しています. この研究は,酵素の機能に不可欠な,ダイオキシゲン活性化のための主要な反応経路を特定します.
科学分野:
- バイオケミストリー バイオケミストリー
- コンピューティング・ケミストリー
- 酵素学 酵素学とは
背景:
- リボヌクレオチド還元酵素のような非ヘム二鉄酵素は,生物学的プロセスに不可欠です.
- これらの酵素におけるダイオキシゲン活性化のメカニズムを理解することは,それらの機能にとって極めて重要です.
研究 の 目的:
- 非ヘム二鉄リボヌクレオチド還元酵素における化学的に可能なペロキソ型中間物質を体系的に研究する.
- 酵素反応におけるこれらの中間物質の活性化における水または陽子の役割を明らかにする.
主な方法:
- スペクトロスコーピカル校正による密度関数計算を用いた.
- 計算した均衡構造,振動周波数,モスバウアー同位体シフト,電子特性.
- O{2},陽子,水の結合エネルギーが研究されている.
主要な成果:
- 様々なペロキソ中間物質とその性質を特徴づけた.
- 水または陽子の結合を含む中間活性化のための2つの潜在的な反応経路を特定しました.
- 水の調整が結晶構造で観察される形状の変化を誘導することを示した.
結論:
- 陽子または水の二鉄部位への結合は,電子構造の変化を促進し,過酸化中介物質を活性化します.
- ペロキシ中介物質を活性化するために2つの経路が提案されており,Fe (III) Fe (IV) 中介物質Xの形成につながる.
- この発見は,この酵素クラスにおけるO(2) 反応中のカルボキシラート構成変化の新たな根拠を提供している.
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