短いアラニンベースのペプチドは,水溶液で3(10) -ヘリクスを形成し,アルファヘリクスを形成しない可能性があります
S M Miick1, G V Martinez, W R Fiori
1Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
Nature
|October 15, 1992
まとめ
短いアラニンペプチドはアルファヘリクスを形成する可能性があるが,アルファヘリクスと3(10) -ヘリクスを区別することは困難である. 新しいスピンラベリング技術により,これらのペプチドは溶液中の3~10の螺旋状構造を採用する可能性が高いことが明らかになった.
科学分野:
- 生物物理化学 生物物理化学とは
- 構造生物学 構造生物学とは
- ペプチド科学 ペプチド科学とは
背景:
- 短いアラニンペプチド (16〜17残基) は,水溶液でアルファヘリクスを形成すると考えられている.
- 円形の二重化 (CD) や核磁気共鳴 (NMR) などの標準的なスペクトロスコーピ手法では,アルファヘリックスと3・10・ヘリクスを区別することができません.
- 3(10) -ヘリクスは,アルファヘリクスのi〜i+4結合とは異なるi〜i+3残留水素結合を伴う.
研究 の 目的:
- 短いアラニンペプチドのアルファヘリカル構造と3~10ヘリカル構造を区別するための新しい方法を開発し,適用する.
- 先進的なスペクトロスコーピテクニックを使用して,アラニンベースのペプチドの二次構造の好みを調査する.
主な方法:
- シングルおよびダブルスピンラベルのアラニンペプチドアナログの設計と合成.
- システイン残留物を介して,窒酸化窒素のスピンラベルを組み込む.
- 円形二重化 (CD),フーリエ変換赤外線 (FTIR) スペクトロスコピー,電子回転共振 (ESR) スペクトロスコピーを用いた分析.
主要な成果:
- FTIRアミドI'帯の周波数は,アルファヘリクスの典型的な周波数と有意に異なっていた.
- ダブルラベルペプチドのESRスペクトルは,アルファヘリル形状と一致しないサイドチェーン距離の順位を示した.
- 実験データでは,3~10本の螺旋構造が強く示唆されています.
結論:
- この研究では,短いアラニンペプチドのアルファヘリクル構造と3・10・ヘリクル構造の区別が成功しました.
- スピン・ラベリングと複数のスペクトロスコピ的方法が併用され,ペプチド構造の決定に強力なアプローチを提供します.
- この研究結果は,短アラニンペプチドが溶液中の3・10・螺旋状の形状を主に採用していることを示しています.
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