アンフィンセン原理の拡張:合理的なタンパク質設計に同義的なコドン選択の貢献
Ian M Sander1, Julie L Chaney, Patricia L Clark
1Department of Chemistry & Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Journal of the American Chemical Society
|January 8, 2014
まとめ
タンパク質の折り畳みは,合成の速度によって影響を受けます. リボソーム合成中のコトランスレーション式折り畳みは,特定の構造を好み,in vitro再折り畳みの結果とは異なる.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- タンパク質の折りたたみ
背景:
- Anfinsenの原理は,タンパク質の構造は,アミノ酸の配列によってのみ決定されると述べています.
- 新生ポリペプチド鎖は,まだリボソームで合成されている間,折り畳み始めることができます.
研究 の 目的:
- コトランスレーションによる折りたたみによるタンパク質の構造が,in vivoでの折りたたみによるタンパク質の構造が,in vitroでの折りたたみによるタンパク質の構造に変化するかどうかを調べる.
- タンパク質合成の速度が最終の折りたたみ状態に影響するかどうかを判断する.
主な方法:
- 競合するN-末端とC-末端ドメインを持つ光タンパク質を設計した.
- タンパク質の折りたたみを化学的変性化 (in vitro) 後と,Escherichia coli (in vivo) のトランスレーション時に比較した.
- 翻訳速度を調節するために同義的なコドン置換を用いた.
主要な成果:
- 実験室での再折りたたみにより,競合する2つの構造の等分量が得られました.
- In vivo翻訳では,N-末端構造に対する2倍の好みが示されました.
- コドン選択による変換速度の変更により,N端構造の選択がさらに強化された.
結論:
- リボソームから新生タンパク質が出現する速度は,最終的な折りたたまれたタンパク質構造を決定します.
- コトランスレーション折り合いは,タンパク質の構造形成をバイアスするメカニズムを提供します.
- タンパク質の折り畳みは,アミノ酸配列のみによって決定されるのではなく,合成プロセスによっても決定されます.
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