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arXiv 2209.14852cond-mat.soft
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接近液-液相分离的蛋白质溶液表现出普适的渗透状态方程和动力学行为

Protein solutions close to liquid-liquid phase separation exhibit a universal osmotic equation of state and dynamical behavior

Jan Hansen, Stefan U. Egelhaaf, Florian Platten

摘要:

蛋白质溶液的液-液相分离(LLPS)由高度复杂的蛋白质-蛋白质相互作用控制。然而,有人建议,根据扩展的对应态定律(ELCS),建议与短程吸引力的胶体,人们可以合理化不仅是热力学,而且结构和动力学的系统。本文通过静态和动态光散射实验对这一主张进行了系统和全面的检验。旋节线,等温渗透压缩性$κ_\text{T}$和浓度波动的弛豫速率$Γ$的蛋白质溶液中的LLPS附近确定。所有这些量都表现出对应态行为。这意味着,对于不同的溶液条件,如果在相似的折合温度或第二维里系数下考虑,这些量基本上是相同的。对于中等浓度的溶液,$κ_\text{T}$和$Γ$的体积分数$ϕ$依赖性可通过Baxter的粘附性硬球模型一致地描述。接近LLPS的$κ_\text{T}$和$Γ$的非临界渐近$T$行为与平均场论预测的标度律一致。因此,本工作的目的是在一个全面的实验测试的ELCS浓缩蛋白质溶液的结构和动力学性质的适用性。

英文摘要:

Liquid-liquid phase separation (LLPS) of protein solutions is governed by highly complex protein-protein interactions. Nevertheless, it has been suggested that based on the extended law of corresponding states (ELCS), as proposed for colloids with short-range attractions, one can rationalize not only the thermodynamics, but also the structure and dynamics of such systems. This claim is systematically and comprehensively tested here by static and dynamic light scattering experiments. Spinodal lines, the isothermal osmotic compressibility $κ_\text{T}$ and the relaxation rate of concentration fluctuations $Γ$ are determined for protein solutions in the vicinity of LLPS. All these quantities are found to exhibit a corresponding-states behavior. This means that, for different solution conditions, these quantities are essentially the same if considered at similar reduced temperature or second virial coefficient. For moderately concentrated solutions, the volume fraction $ϕ$ dependence of $κ_\text{T}$ and $Γ$ can be consistently described by Baxter's model of adhesive hard spheres. The off-critical, asymptotic $T$ behavior of $κ_\text{T}$ and $Γ$ close to LLPS is consistent with the scaling laws predicted by mean-field theory. Thus, the present work aims at a comprehensive experimental test of the applicability of the ELCS to structural and dynamical properties of concentrated protein solutions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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