グアニジニウム塩化物の水溶液の構造
Philip E Mason1, George W Neilson, John E Enderby
1Contribution from the Department of Food Science, Stocking Hall, Cornell University, Ithaca, NY 14853, USA.
Journal of the American Chemical Society
|September 16, 2004
まとめ
グアニジニウム塩化物の溶液は,ユニークなイオン-イオン配列を示しています. この構造は,同位素置換による中性子 difraktion と分子動力学シミュレーションによって明らかにされ,グアニジニウムクロライドがタンパク質をデナチュア化する方法を説明しています.
科学分野:
- 物理化学 物理化学
- 溶液化学について
- バイオ物理化学 バイオ物理化学
背景:
- グアニジニウム塩化物は,一般的なタンパク質デナチュラントです.
- その解の構造を理解することは,その機能の鍵です.
- 以前の研究では,塩化グアニジニウム溶液の構造に関する詳細な洞察が欠けている.
研究 の 目的:
- 水性グアニジニウム塩化物溶液の構造を特徴付けるために.
- イオン-イオン関連と水分化パターンを調査する.
- グアニジニウム塩化物のデナチュレーション能力の分子基礎を解明する.
主な方法:
- 同位体置換 (NDIS) による結合中性子 difraktion 実験.
- 実行された分子動力学 (MD) シミュレーション.
- 室温で3Mグアニジニウム塩化物溶液を研究した.
主要な成果:
- MDシミュレーションは,実験的な中性子散乱特性を正確に再現しました.
- グアニジニウムイオンは,オーダーされたN-H水素結合と水不足の平面面によって,双方向の水分化を示す.
- グアニジニウムイオンが水不足の表面に平行して積み重なって,有意なイオン-イオン順序が観察されました.
結論:
- グアニジニウム塩化物の溶液には,豊富なイオン-イオン配列が表示されます.
- デナチュレーション効率は,グアニジニウムが水とタンパク質の両方の水嫌性サイドチェーンと相互作用する能力から生じる.
- 観察された構造は,グアニジニウム塩化物のタンパク質の無性化特性に対する分子的な説明を提供します.
関連する概念動画
01:12Solvents
A solvent is a substance, most often a liquid, that can dissolve other substances. Here, the substance being dissolved is called a solute. When a solvent and a solute combine, they form a solution - a homogenous mixture of both the solvent and the solute. Water is a universal biological solvent. Its polar structure allows it to dissolve many other polar compounds. The ability of water to dissolve is governed by a balance between water molecules binding to each other and binding to the solute.
A...
A...
02:30Water: A Bronsted-Lowry Acid and Base
The reaction between a Brønsted-Lowry acid and water is called acid ionization. For example, when hydrogen fluoride dissolves in water and ionizes, protons are transferred from hydrogen fluoride molecules to water molecules, yielding hydronium ions and fluoride ions:
04:01Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
03:00Solubility
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules, atoms, and/or ions)...
02:36Acidity and Basicity of Alcohols and Phenols
Like water, alcohols are weak acids and bases. This is attributed to the polarization of the O–H bond making the hydrogen partially positive. Moreover, the electron pairs on the oxygen atom of alcohol make it both basic and nucleophilic. Protonation of an alcohol converts hydroxide, a poor leaving group, into water—a good one. The two acid–base equilibria corresponding to ethanol are depicted below.
01:20Aldehydes and Ketones with Water: Hydrate Formation
An oxygen-based nucleophile, like water, can undergo addition reactions with aldehydes and ketones. The reaction leads to the formation of hydrates, also referred to as 1,1-diols or geminal diols.
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...
The formation of hydrates is a reversible reaction. Hydrate formation is influenced by steric and electronic factors accompanying the alkyl substituents on the carbonyl group: The rate of hydrate formation increases with a decrease in the number of alkyl groups attached to the carbonyl carbon. Hence,...