Tulane University, New Orleans, Louisiana 70115, United States.
Biomacromolecules. 2024 Aug 12;25(8):5198-5211. doi: 10.1021/acs.biomac.4c00583. Epub 2024 Jul 29.
Monitoring membrane-mediated dialysis in real time with static and dynamic light scattering revealed distinctive differences, including reversibility/irreversibility, in the effects of ionic strength (NaCl) and the denaturant guanidine-HCl (Gd) on a synthetic polyelectrolyte and several types of biomacromolecules: protein, polysaccharide, and polyampholyte. Dialysis cycles against aqueous NaCl and Gd, and reverse back to the original aqueous solution, were monitored. The behavior of Na-polystyrenesulfonate was reversible and yielded a detailed polymer physics description. The biomacromolecules additionally showed hydrogen-bonding/hydrophobic (HP) interactions. An interpretive model was developed that considers the interplay among polyelectrolyte, polyampholyte, and HP potential energies in determining the different associative, aggregative, and dissociative behaviors. NaCl isolated purely electrostatic effects, whereas Gd combined electrostatic and HP effects. Some macromolecules showed partially reversible behavior, and others were completely irreversible. The dialysis monitoring method should prove useful for investigating fundamental macromolecular and colloid properties and for drug formulation and stability optimization.
利用静态和动态光散射实时监测膜介导的透析，揭示了离子强度（NaCl）和变性剂盐酸胍（Gd）对合成聚电解质和几种生物大分子（蛋白质、多糖和两性聚电解质）的影响的显著差异，包括可逆性/不可逆性。监测了针对水溶液 NaCl 和 Gd 的透析循环，并反向回到原始水溶液。Na-聚苯乙烯磺酸盐的行为是可逆的，并提供了详细的聚合物物理描述。生物大分子还显示出氢键/疏水（HP）相互作用。开发了一种解释模型，该模型考虑了聚电解质、两性聚电解质和 HP 势能之间的相互作用，以确定不同的缔合、聚集和解离行为。NaCl 仅分离出纯静电效应，而 Gd 则结合了静电和 HP 效应。一些大分子表现出部分可逆行为，而其他则完全不可逆。透析监测方法应该有助于研究基本的大分子和胶体性质，以及药物配方和稳定性优化。
