フェリサイトクロームCのアルカリ的形態の構造モデル
Michael Assfalg1, Ivano Bertini, Alessandra Dolfi
1CERM, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy.
Journal of the American Chemical Society
|March 6, 2003
まとめ
NMR光学により,酵母Iso-1-ferricytochrome cは高pHで本来の構造を維持しており,主な違いは70-80ループに局限しており,ヘム曝露の増加と高タンパク質流動性につながっていることが明らかになりました.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- 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:
- サイトクロームcは,細胞呼吸における重要なタンパク質です.
- 異なるpHレベルでの構造的動態を理解することは不可欠です.
- 変異は,タンパク質の構造と機能を変化させることができます.
研究 の 目的:
- トリプルバリエーションの酵母イソ-1-フェリサイトクロームcの高pH構成を調査する.
- 変異が単一のタンパク質コンフォマーを生成するかどうかを判断する.
- NMRスペクトロスコーピーを用いて構造変化とダイナミクスを分析する.
主な方法:
- 核磁共振 (NMR) スペクトロスコーピーは,15Nで濃縮されたサンプルで実施されます.
- パラマグネチズムは,アルカリ条件下 (pH ~11) のスペクトル分析に使用されます.
- アミノ酸と陽子の割り当て,NOE分析,および構造計算.
主要な成果:
- アミノ酸の76%と陽子の49%が順調に割り当てられました.
- Lys73は,His18.18と共に軸性リンガンドとして識別されました.
- 構造計算により,バックボーンRMSDが1.5 Åのコンフォマーファミリーが得られました.
- ネイティブコンフォームは大きく維持され,70-80ループの違いとヘム曝露の増加があります.
結論:
- NMRは,最適でない条件下でもタンパク質の研究に有効です.
- イースト iso-1-ferricytochrome cの変種は,高いpHで有意なネイティブ構造を維持しています.
- このタンパク質は,特に70〜80のループ領域において,高い流動性を示しています.
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