高濃度の塩が水の構造に与える影響

R Leberman¹, A K Soper

¹European Molecular Biology Laboratory, Grenoble Outstation, BP 156, 38042 Grenoble Cedex, France.

Nature

|November 23, 1995

まとめ

水溶液中のイオンは,その構造を破壊し,高圧を模倣します. このイオン特異的な効果は,部分モラ体積と関連しており,タンパク質の降水と塩化現象に影響を与えます.

科学分野:

物理化学物理化学とは
溶液化学溶液化学とは
生物物理化学生物物理化学とは

背景:

水の四面体構造は,圧力と温度に敏感です.
溶液中のイオンは,水の水素結合ネットワークを乱す可能性があります.
イオンと水の相互作用を理解することは,様々な化学的,生物学的プロセスにとって極めて重要です.

研究の目的:

施された圧力の構造的効果と,水の塩分濃度の高さを比較する.
これらの構造的混乱のイオン特異的な性質を調査する.
イオン誘発の構造変化とタンパク質の塩化効果を相関させるため.

主な方法:

ニュートロン difraktionは,異なる条件下で水の構造を調査するために使用されました.
高い塩分濃度と施された圧力は,体系的に変化した.
構造の変化はイオン特性との関係で分析されました.

主要な成果:

イオンは水中の構造変化を誘導し,高圧 (数mol/Lで1000 atm以上) に相当する.
この圧力効果の大きさは,イオン種に特異的です.
誘導された圧力とタンパク質の塩化におけるイオンの有効性との間には相関が観察されました.

結論:

水の構造のイオンによる干渉は,有意な水静圧の適用に類似しています.
水分子に対するイオンの部分モラ体積は,観測された構造変化を説明する.
この研究は,タンパク質の降水と溶液の振る舞いにおけるイオン特異的効果を理解するための分子基盤を提供します.

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