単電子還元サイクルによるヘム・ノンヘム双核合成ミオグロビンにおける酸化窒素還元酵素の活性
Sinan Sabuncu1, Julian H Reed2, Yi Lu2
1Department of Biochemistry & Molecular Biology , Oregon Health & Science University , Portland , Oregon 97239 , United States.
Journal of the American Chemical Society
|December 5, 2018
まとめ
エンジニアリングされたミオグロビンモデル (FeBMbs) は,細菌の酸化窒素還元酵素 (NORs) を真似しています. これらのモデルは様々な金属イオンとのNOR活性を示し,酸化窒素の還元のための1電子経路をサポートします.
科学分野:
- 生物化学
- バイオ有機化学
- 酵素ミミックス
背景:
- バクテリアの酸化窒素還元酵素 (NOR) は窒素循環に不可欠です.
- ミオグロビン工学は,NORの機能モデルであるFeBMbsを生成しました.
- これらのモデルは,NORを模倣するダイアイロンの活性部位を備えています.
研究 の 目的:
- エンジニアリングされたFeBMb1タンパク質におけるNORのターンオーバーを調査する.
- FeBサイトにおける異なる金属イオンの役割を調査する.
- 酸化窒素の減少における反応経路の証拠を提供する.
主な方法:
- モノフォーミル・ヘムを含むFeBMb1タンパク質の構成
- FeBサイトをFeII,CoII,またはZnIIでロードしています.
- フーリエ変換赤外線 (FTIR) スペクトロスコーピーは,N2O製品を検出する.
主要な成果:
- 多数の酸化窒素還元酵素の転用が観察されました.
- FeII-FeBMb1(MF-heme) は最大回転率を示した.
- FeB部位で ZnIIで NOR活性が維持された.
- FTIRはN2Oの量的な測定を提供した.
結論:
- FeBMbsは,NORメカニズムを研究するための実行可能な機能モデルです.
- 結果は,NOの減少のための1電子半減経路を支持する.
- 二核センターは,還元条件下で酸化窒素の還元に有効です.
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