The effect of charged residue substitutions on the thermodynamics of protein-surface interactions.
The effect of charged residue substitutions on the thermodynamics of protein-surface interactions.
复制标题
带电残基取代对蛋白质-表面相互作用热力学的影响。
DOI：
10.1002/pro.4215
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Plaxco,KevinW
中科院分区：
文献类型：
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作者：
Ortega,Gabriel;Aguilar,MiguelA;Gautam,BishalK;Plaxco,KevinW
蛋白质与表面的相互作用在生物过程和生物技术中都很重要。然而，与几十年来关于散装溶液中蛋白质生物物理学的研究相反，我们对蛋白质与表面相互作用的生物物理学的机制理解在很大程度上仍然是定性的。作为回应，我们已经开始定量地探索蛋白质表面相互作用的热力学。在这项工作中，我们系统地探索了静电在调节蛋白质和带电表面之间相互作用中的作用。特别是，我们使用电化学来探索宏观的，羟基涂层表面保持在微负电位的程度，影响具有不同带电氨基酸组成的表面附着蛋白变体的折叠热力学。这样做，我们发现附着在表面通常会导致净稳定，可能是由于排除了体积效应，减少了展开态的熵。然而，这种稳定性的大小与蛋白质的带电残基含量密切相关。特别是，我们发现与蛋白质的净电荷（负电荷越大，表面稳定性越差）和精氨酸的数量（精氨酸越多，稳定性越好）之间存在统计学上显著的相关性。这些发现完善了我们对蛋白质-表面相互作用的理解，反过来为实现蛋白质在人工表面的功能性沉积提供了指导理论依据，例如，基于蛋白质的生物技术。
The interactions of proteins with surfaces are important in both biological processes and biotechnologies. In contrast to decades of study regarding the biophysics of proteins in bulk solution, however, our mechanistic understanding of the biophysics of proteins interacting with surfaces remains largely qualitative. In response, we have set to explore quantitatively the thermodynamics of protein‐surface interactions. In this work, we explore systematically the role of electrostatics in modulating the interaction between proteins and charged surfaces. In particular, we use electrochemistry to explore the extent to which a macroscopic, hydroxyl‐coated surface held at a slightly negative potential affects the folding thermodynamics of surface‐attached protein variants with different composition of charged amino acids. Doing so, we find that attachment to the surface generally leads to a net stabilization, presumably due to excluded volume effects that reduce the entropy of the unfolded state. The magnitude of this stabilization, however, is strongly correlated with the charged‐residue content of the protein. In particular, we find statistically significant correlations with both the net charge of the protein, with greater negative charge leading to less stabilization by the surface, and with the number of arginines, with more arginines leading to greater stabilization. Such findings refine our understanding of protein‐surface interactions, providing in turn a guiding rationale to achieve the functional deposition of proteins on artificial surfaces for implementation in, for example, protein‐based biotechnologies.