Gao Tadeja, Korb Jean-Pierre, Lukšič Miha, Mériguet Guillaume, Malikova Natalie, Rollet Anne-Laure
Sorbonne Université/CNRS, Laboratoire Physico-Chimie des Électrolytes et Nano-Systèmes Interfaciaux (PHENIX), 4 place Jussieu, Paris, France.
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana SI-1000, Slovenia.
J Mol Liq. 2022 Dec 1;367(Pt A). doi: 10.1016/j.molliq.2022.120451. Epub 2022 Sep 24.
In all biologically relevant media, proteins interact in the presence of surrounding ions, and such interactions are water-mediated. Water molecules play a crucial role in the restructuring of proteins in solution and indeed in their biological activity. Surface water dynamics and proton exchange at protein surfaces is investigated here using NMR relaxometry, for two well-known globular proteins, lysozyme and bovine serum albumin, with particular attention to the role of surface ions. We present a unified model of surface water dynamics and proton exchange, accounting simultaneously for the observed longitudinal and transverse relaxation rates. The most notable effect of salt (0.1 M) concerns the slow surface water dynamics, related to rare water molecules embedded in energy wells on the protein surface. This response is protein-specific. On the other hand, the proton exchange time between labile protein-protons and water-protons at the protein surface seems to be very similar for the two proteins and is insensitive to the addition of salts at the concentration studied.
在所有具有生物学相关性的介质中，蛋白质在周围离子存在的情况下相互作用，并且这种相互作用是由水介导的。水分子在溶液中蛋白质的重构以及其生物活性方面起着至关重要的作用。本文利用核磁共振弛豫测量法研究了两种著名的球状蛋白质——溶菌酶和牛血清白蛋白表面的水动力学和质子交换，特别关注表面离子的作用。我们提出了一个表面水动力学和质子交换的统一模型，同时考虑了观测到的纵向和横向弛豫速率。盐（0.1 M）最显著的影响涉及缓慢的表面水动力学，这与嵌入蛋白质表面能量阱中的稀有水分子有关。这种响应是蛋白质特异性的。另一方面，两种蛋白质在蛋白质表面不稳定的蛋白质质子与水质子之间的质子交换时间似乎非常相似，并且在所研究的浓度下对盐的添加不敏感。
