プリオンタンパク質のオクタレペイトドメインは,pH7.4で3つの異なる調整モードでCuを結合する
Madhuri Chattopadhyay1, Eric D Walter, Dustin J Newell
1Department of Chemistry & Biochemistry, University of California, Santa Cruz, California 95064, USA.
Journal of the American Chemical Society
|September 8, 2005
まとめ
プリオンタンパク質 (PrP) は,銅イオン (Cu2+) をそのオクターレピート領域を通して結合する. この研究では,pH7.4の銅の3つの異なる協調モードが明らかになり,PrP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
- 構造生物学 構造生物学とは
- バイオ・オーガニック化学 バイオ・オーガニック化学
背景:
- プリオンタンパク質のN端オクトレペイトドメインはCu2+イオンと結合する.
- 基本的な繰り返しのシーケンスがPHGGGWGQです.
- 以前の研究では,銅の完全占用は,HGGGWの各セグメントがCu2+を1つ結合することを含むことを示しました.
研究 の 目的:
- 低銅占有率でプリオンタンパク質オクターレピート領域における銅の調整モードを調査する.
- ヒスティジン残留物の潜在的関与を,代替調整において調査する.
- オクターレピート領域における銅に依存する構造変化の特徴づけ.
主な方法:
- X帯電子パラマグネット共振 (EPR),S帯 EPR,電子スピンエコーエンベロープ調節 (ESEEM) を利用しました.
- 特定の協調相互作用を促進するために,改変されたペプチドのライブラリを使用した.
- 分析された銅の調整モードは,pH7.4でpH7.4でした.
主要な成果:
- 銅の3つの異なる調整モードをpH7.4で特定し,完全に特徴づけました.
- 低銅ステキオメトリーで複数のヒスティジン調整が確認されました.
- 満席時に銅と銅の相互作用が検出され,ドメインの崩壊と協同的な銅の吸収を示唆しています.
結論:
- PrPオクタレペイトドメインの7.4.pHでの支配的な銅の調整モードの最初の包括的な特徴付けを提供します.
- 異なる銅濃度での銅結合の構造的基礎を解明する.
- 低銅環境におけるヒスティジン調整と,高銅環境におけるドメイン崩壊の役割を強調する.
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