盐对同型相分离的直接和间接作用
Matt MacAinsh1, Souvik Dey1, Huan-Xiang Zhou1,2
1Department of Chemistry, University of Illinois Chicago, Chicago, United States.
eLife
|November 12, 2024
概括
hnRNPA1 (A1-LCD) 的低复杂性域经历盐依赖相分离,由高盐度促进. 这种非典型的行为是由离子电荷中和和桥接驱动的,以及在较高的盐分水平下加强的π相互作用.
科学领域:
- 生物物理学的生物物理.
- 分子生物学分子生物学
- 计算生物学 计算生物学
背景情况:
- 内在无序的蛋白质 (IDPs) 经历液体-液体相分离 (LLPS),这是细胞组织中的一个关键过程.
- hnRNPA1 (A1-LCD) 的低复杂性域表现出不寻常的依赖盐的相分离,与典型的IDP不同.
研究的目的:
- 为了研究非典型的盐对A1-LCD相位分离的影响.
- 阐明A1-LCD的盐促进LLPS背后的分子机制.
主要方法:
- 采用了全原子分子动力学 (MD) 模拟.
- 在多个A1-LCD链上进行了模拟,在NaCl度 (501000mM) 的范围内进行模拟.
主要成果:
- NaCl 离子直接中和蛋白质的净电荷,并在 A1-LCD 链之间形成桥梁,促进凝结.
- 高盐度通过减少水屏蔽来间接增强π-π,-π和氨基-π相互作用.
- 低盐度通过电荷排斥阻止相位分离;中等和高盐度通过电荷中和,桥接和加强π相互作用促进相位分离.
结论:
- 非典型的盐促进的A1-LCD相分离是由直接的离子介导相互作用和对非共价力间接影响的组合所支配的.
- 该研究预测了基于氨基酸组成的IDP相分离的四类盐依赖.
相关概念视频
Ionic Strength: Effects on Chemical Equilibria
1.4K
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary...
In this solution, the primary...
1.4K
Common Ion Effect
41.1K
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 Châtelier’s principle. Consider the dissolution of silver iodide:
41.1K
Electrolytes: van't Hoff Factor
32.9K
Colligative Properties of Electrolytes
The colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. Nonelectrolytes dissolve physically without dissociation or any other accompanying process. Each molecule that dissolves yields one...
The colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. Nonelectrolytes dissolve physically without dissociation or any other accompanying process. Each molecule that dissolves yields one...
32.9K
Solubility Equilibria: Overview
605
When a substance such as sodium chloride is added to water, it dissolves, forming an aqueous solution. The extent of dissolution is called solubility. The process of dissolution can exist in equilibrium, just like other chemical processes. Solubility equilibria are also called precipitation equilibria because the process of solubility can be reversible. The reverse of the solubility process is called precipitation.
Solubility is important in biological and environmental processes. A notable...
Solubility is important in biological and environmental processes. A notable...
605
Aqueous Solutions and Heats of Hydration
14.4K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
14.4K
Intermolecular Forces in Solutions
33.1K
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
33.1K


