酸化窒素とオキシミオグロビンの反応におけるミリ秒間 intermediate は,鉄 (III) - ニートラート複合体であり,ペロキシニートではない
Erik T Yukl1, Simon de Vries, Pierre Moënne-Loccoz
1Department of Science and Engineering, School of Medicine, Oregon Health & Science University, Beaverton, Oregon 97006-8921, USA.
Journal of the American Chemical Society
|May 28, 2009
まとめ
研究者らは,マイオグラビンによる酸化窒素の解毒における重要な中間物質を特定した. この研究は,この重要な生物学的プロセスにおけるミリ秒間の中間体として,推定の鉄 (III) -ペロキシニトリットではなく,鉄 (III) -ニトラート複合体を明らかにしています.
科学分野:
- バイオケミストリー バイオケミストリー
- 生物物理化学 生物物理化学
背景:
- 酸化窒素 (NO) の解毒は,有酸素生物学的システムにおいて極めて重要です.
- グロービンタンパク質は,ミオグロービンと同様に,NOの酸化のためにオキシヘムを使用します.
- 反応メカニズムは,鉄 (III) -ペロキシニート中間物質を含むと推定されています.
研究 の 目的:
- マイオグロービンのNO二酸化酸素化におけるミリ秒高スピンヘム中間物質の特徴を特定する.
- NOの解毒中に形成される遷移性種の正確な構造を解明する.
主な方法:
- 単一のターンオーバー実験をアルカリ性pHで行う.
- 急速凍結で消火する技術.
- 共振ラーマン光譜法.
主要な成果:
- ミリ秒間の高スピンヘム中間物質が検出されました.
- この中間物質は,鉄 (III) - ニートラート複合体として特定されました.
- 1282cm(-1) の対称的なNO(2) 伸縮は,ナイトラート構造を確認した.
結論:
- マイオグルビン NO の酸化酸化における支配的なミリ秒間隔は,鉄 (III) - ニートラート複合体である.
- 推定される鉄 (III) -ペロキシニート中間物質は,より高い時間解像度の技術によるさらなる調査を必要とします.
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