モノチオールグルタレドキシンは, [Fe2S2]2+クラスターに加えて,線形[Fe3S4]+と[Fe4S4]2+クラスターに結合することができる:光譜的特徴と機能的影響
Bo Zhang1, Sibali Bandyopadhyay, Priyanka Shakamuri
1Department of Chemistry and Center for Metalloenzyme Studies, University of Georgia , Athens, Georgia 30602, United States.
Journal of the American Chemical Society
|September 17, 2013
まとめ
Saccharomyces cerevisiaeミトコンドリアルグルタレドキシン5 (Grx5) は,以前考えられていたように, [Fe2S2] (Fe2+) クラスターだけでなく,主に線形 [Fe3S4] (Fe3S4) +) クラスターを含んでいます. この発見は,鉄と硫黄のクラスター取引とタンパク質の成熟に関する理解に影響を与えます.
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
- 分子生物学は分子生物学である.
背景:
- Saccharomyces cerevisiaeミトコンドリアルグルタレドキシン5 (Grx5) は,鉄硫黄クラスター取引に関与する主要なモノチオールグルタレドキシンです.
- CGFSの活性部位配列は,モノチオールグルタレドキシンに保存され,鉄硫黄集束の処理における共通の機能を示唆しています.
- 以前の研究では,モノチオールGrxsの鉄硫黄クラスター含有量を[Fe2S2](2+) クラスターとして解釈することが多かった.
研究 の 目的:
- 再結合型サッカロマイケシ・セレヴィシア (Saccharomyces cerevisiae Grx5.5) の鉄と硫黄のクラスター組成を特徴付けるために.
- Grx5.5に結合した鉄硫黄クラスターの構造および電子特性を調査する.
- 鉄硫黄のクラスター取引とタンパク質の成熟におけるGrx5の役割を明らかにする.
主な方法:
- 再結合されたS. cerevisiae Grx5をエアロビックおよび無酸素条件で浄化する.
- 紫外線による吸収/CD/MCD,EPR,Mössbauer,および共振ラマンスペクトルスコピーを含むスペクトルスコピカル特徴付け.
- クラスター結合を評価するための変異と分析の研究.
主要な成果:
- 再結合Grx5は主に,グルタチオンでエアロビック浄化またはアナエロビック再構成されたとき,線形[Fe3S4](+) クラスタを含んでいます.
- 顕微鏡データは,合成アナログと紫色アコニタゼに似たロムビックS = 5/2線形[Fe3S4](+) クラスタを明らかにしています.
- グルタチオンがない場合,Grx5は[Fe4S4](2+) クラスタを持つダイマーを形成し,インビトロアポアコニタゼ活性化が可能である.
結論:
- Grx5を含むモノチオールGrxsの鉄硫黄クラスター含有量は,主に誤って解釈されており,線形[Fe3S4](+) クラスターが優勢である.
- Grx5は,酸化ストレス下での線形[Fe3S4](+) クラスタの除去とリサイクル,および[Fe4S4](2+) を含むタンパク質の成熟に役割を果たします.
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