β-バレルのタンパク質の水分化ダイナミクスのマッピング
Jin Yang1, Yafang Wang1, Lijuan Wang1
1Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States.
Journal of the American Chemical Society
|March 2, 2017
まとめ
タンパク質の水分化ダイナミクスは,アルファヘリカルタンパク質とベータシートタンパク質の両方に対して異質である. 水分化の水の動態はタンパク質のリラックスよりも速く,タンパク質の変動に影響を与え,二次構造によって異なる.
科学分野:
- バイオ物理学
- 構造生物学
- タンパク質ダイナミクス
背景:
- タンパク質表面の水分化は タンパク質の構造,柔軟性,動力,機能に不可欠です
- タンパク質の構造と水分化のダイナミクスとの関係を理解することは困難です.
研究 の 目的:
- ネズミの肝脂肪酸結合タンパク質 (rLFABP) の周辺の水分化ダイナミクスを体系的に特徴づける.
- 異なるタンパク質二次構造 (ベータシート対アルファヘリックス) が水分化水に与える影響を明らかにする.
主な方法:
- タンパク質の表面に トリプトファンのスキャンを使って 17の異なる部位を調べた
- 超高速スペクトロスコーピーを用いて,水分放緩とトリプトファンの横鎖アニソトロピーのダイナミクスを観察した.
主要な成果:
- 3つの異なる水分放緩時間スケール (数百フェムト秒から数百ピコ秒) を観測した.
- 2つの異なるトリプトファンの横鎖のリラックス時間スケール (数十から数百ピコ秒) を特定した.
- 発見された水分化の動態は異質で,外層の水はより速く (数百フェムト秒),内層の水はピコ秒から百ピコ秒の時間スケールでリラックスする.
結論:
- 水分化の動態はタンパク質のリラックスよりも速く,ピコ秒スケールのタンパク質の変動を誘導します.
- アルファヘリカルモチーフと比較して,ベータシート構造の周りの水分化ダイナミクスは一般的に遅い.
- ベータシートタンパク質は,アルファヘリカルタンパク質よりも厚い水分化殻とより硬いインターフェイス水分化ネットワークを示します.
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