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Monitoring the Effect of Osmotic Stress on Secretory Vesicles and Exocytosis
Published on: February 19, 2018
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生物学的オスモライトによる表面積の調節
Roy Govrin1, Itai Schlesinger1, Shani Tcherner1
1Department of Physics and the Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Technion City, Haifa 3200003, Israel.
Journal of the American Chemical Society
|October 4, 2017
まとめ
尿素やグリセロールのような中性オスモライトは,シリカ表面の電荷を大きく変化させ,タンパク質の安定性に影響を及ぼします. この効果は標準的なモデルで予測されたものよりはるかに大きく 細胞の相互作用に関する新しい洞察を明らかにしています
科学分野:
- バイオ物理学
- 表面化学
- 分子 相互作用
背景:
- オスモライトはタンパク質の安定性と機能に不可欠であり,細胞塩と陽子と相互作用するメカニズムは完全に理解されていません.
- オスモライトと表面の相互作用を理解することは,環境の変化に対する細胞の反応を説明する鍵です.
研究 の 目的:
- 生物学的オスモライト (尿素とグリセロール) がシリカの表面積に与える影響を調査するために,プロティック表面のモデル.
- 中性オスモライトが表面電荷と界面特性に影響を与えるメカニズムを解明する.
主な方法:
- 超高解像度周波数変調原子力顕微鏡 (FM-AFM) を使用してシリカ表面電荷を測定した.
- 表面付近のオスモライトの蓄積/枯渇を評価するために測定された界面液体粘度.
- 量的な分析のためにGouy-Chapman-Sternモデルを適用した.
主要な成果:
- 尿素 (タンパク質不安定剤) は,表面積を50%以上 (pH等価+4) 増加させ,表面積が著しく増加した.
- グリセロール (タンパク質安定剤) は,表面の枯渇とともに,ほぼシリカ表面電荷 (pH等価 - 2) を中和した.
- 観測された表面電荷の変化は,介電定数変化だけで予測されるものより4倍大きかった.
結論:
- 表面反応定数 (シラノール脱陽性,カチオン結合) に起るオスモライトの影響は,主に表面電荷を制御する.
- 中性オスモライトは表面電荷とクーロンビック相互作用に大きな影響を与える.
- 発見は既存のモデルに異議を唱え,生物学的界面現象におけるオスモライトの重要な役割を強調しています.
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