论文标题
接近液体液相分离的蛋白质溶液表现出状态和动力学行为的通用渗透方程
Protein solutions close to liquid-liquid phase separation exhibit a universal osmotic equation of state and dynamical behavior
论文作者
论文摘要
蛋白质溶液的液液相分离（LLP）受高度复杂的蛋白质蛋白相互作用的控制。然而，已经提出，基于相应状态（ELC）的扩展定律，建议针对具有短距离吸引力的胶体，不仅可以合理化热力学，而且可以合理化此类系统的结构和动力学。通过静态和动态的光散射实验，该主张是系统，全面测试的。 Spinodal线，等温渗透压缩性$κ_\ text {t} $和浓度波动的松弛率$γ$是在LLP附近的蛋白质溶液确定的。所有这些数量都表现出相应的州行为。这意味着，对于不同的溶液条件，如果在相似的降温或第二个病毒系数下考虑，这些量基本相同。对于中等浓缩的解决方案，$κ__\ text {t} $和$γ$的体积分数$ ϕ $依赖性可以由Baxter的粘合硬球模型一致地描述。 $κ__\ text {t} $和$γ$接近LLP的非临界，渐近$ t $行为与均值场理论预测的缩放定律一致。因此，目前的工作旨在对ELC对浓缩蛋白质溶液的结构和动力学特性的适用性进行全面的实验测试。
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.
