Wills Peter R, Winzor Donald J
Department of Physics, University of Auckland, PB 92019, Auckland 1142, New Zealand.
School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia.
Biophys Chem. 2017 Sep;228:108-113. doi: 10.1016/j.bpc.2017.07.007. Epub 2017 Jul 20.
Attention is drawn to the thermodynamic invalidity of the current practice of analyzing static light scattering measurements on globular proteins in terms of theory for a single solute because of its disregard of the need to consider small species such as buffer components as additional cosolutes rather than as part of the solvent. This practice continues despite its demonstrated inadequacy in studies of sucrose-supplemented protein solutions, where the aberrant behavior was recognized to be a consequence of physical protein interaction with the small cosolute. Failure to take into account the consequences of small cosolute effects renders extremely difficult any attempt to obtain a rigorous thermodynamic characterization of protein interactions by this empirical technique.
需要注意的是，当前对球状蛋白质进行静态光散射测量分析时，依据单一溶质理论的做法在热力学上是无效的。这是因为该做法忽视了将诸如缓冲液成分等小分子物种视为额外的共溶质而非溶剂一部分的必要性。尽管在对添加蔗糖的蛋白质溶液的研究中已证明这种做法存在不足（在该研究中，异常行为被认为是蛋白质与小分子共溶质发生物理相互作用的结果），但这种做法仍在继续。由于未能考虑小分子共溶质效应的影响，通过这种经验技术对蛋白质相互作用进行严格的热力学表征的任何尝试都变得极为困难。
