高度なEPR特性による粒子メタンモノオキシゲネーゼ銅センターのバレンンスと調整環境の特定
Megen A Culpepper1, George E Cutsail, William A Gunderson
1Departments of ‡Molecular Biosciences and of §Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
Journal of the American Chemical Society
|July 26, 2014
まとめ
粒子のメタンモノオキシゲナーゼ (pMMO) は,メタンを酸化するために銅の中心を使用します. この研究は,二銅部位に1つのEPR活性銅イオンを特定し,pMMOを明確にします.
科学分野:
- バイオケミストリー バイオケミストリー
- 酵素学 酵素学とは
- スペクトロスコーピーは,スペクトロスコーピーを用います.
背景:
- 微粒子メタンモノオキシゲナーゼ (pMMO) は,メタノトロフィック細菌におけるメタン酸化に不可欠である.
- 銅センターは機能の鍵ですが,複数の銅部位があるため,EPRスペクトロスコーピーを用いて特徴づけることは困難です.
研究 の 目的:
- pMMOにおける銅中心の役割と調整環境を,スペクトロスコピ的方法を用いて解明する.
- 溶性再結合断片 (spmoB) をpMMO.を研究するための信頼できるモデルとして検証する.
主な方法:
- 電子パラマグネティック共振 (EPR) スペクトロスコーピーは,電子パラマグネティック共振 (EPR) スペクトロスコーピーを用います.
- 電子核二重共振 (ENDOR) スペクトロスコーピーのスペクトロスコーピーは,電子核二重共振 (ENDOR) スペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロスコーピーのスペクトロス
- 電子・スピン・エコー・エンベロープ・モデレーション (ESEEM) スペクトルスコピー
- 金属含有量の分析
- spmoB変異体のサイト指向型変異.
主要な成果:
- spmoBからのスペクトロスクープデータは,ネイティブpMMOと密接に一致し,spmoBを有効なモデルとして確認しました.
- 1つのEPR活性Cu (II) イオンがpMMOごとに特定され,これは二銅の活性部位内に存在し,バレンスの局所化Cu (I) Cu (II) ペアである.
- モノコッパーサイトはCu ((I)) として割り当てられました.
- 特定のヒスティジン残留物 (His137/His139またはHis33/N末端) は,Cu (II) の調整に関与していた.
- Cu (II) イオンに結合した水中リガンドは見つかりませんでした.
結論:
- この研究は,pMMO.コッパーサイトのアイデンティティとpMMO.コーディネーションを明確にします.
- それは,メタンの酸化機構の将来の調査のための検証されたモデルシステム (spmoB) を提供します.
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