Protein stability and surface electrostatics: A charged relationship
Protein stability and surface electrostatics: A charged relationship
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DOI：
10.1021/bi0600143
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发表时间：
2006-03-07
期刊：
影响因子：
2.9
通讯作者：
Makhatadze, GI
中科院分区：
文献类型：
--
作者：
Strickler, SS;Gribenko, AV;Makhatadze, GI
工程蛋白能够承受广泛的条件仍然是一个令人垂涎的目标，具有推进生物医学，工业和我们对疾病的理解的潜力。实现这一目标的一种方法是阐明定义蛋白质稳定性的潜在相互作用。研究表明，疏水效应、氢键和蛋白质内部残基之间的包装相互作用是决定蛋白质稳定性的主要因素。表面残基在蛋白质稳定性中的作用很少受到关注。人们一直认为，表面残基对蛋白质的稳定性并不重要，特别是因为它们与溶剂的相互作用在天然和未折叠状态下应该是相似的。在表面带电残留物的情况下，有时认为溶剂暴露意味着溶剂的高介电会进一步降低电荷-电荷相互作用的强度。在本文中，我们挑战了表面带电残基对蛋白质稳定性不重要的观念。我们计算重新设计了五种不同蛋白质的序列，以优化表面电荷-电荷相互作用。通过圆二色光谱和差示扫描量热法实验确定，所有重新设计的蛋白质相对于其母体蛋白质表现出显著的稳定性增加。这些结果表明，表面电荷-电荷相互作用对蛋白质的稳定性至关重要，合理优化蛋白质表面的电荷-电荷相互作用可能是提高蛋白质稳定性的可行策略。
Engineering proteins to withstand a broad range of conditions continues to be a coveted objective, holding the potential to advance biomedicine, industry, and our understanding of disease. One way of achieving this goal lies in elucidating the underlying interactions that define protein stability. It has been shown that the hydrophobic effect, hydrogen bonding, and packing interactions between residues in the protein interior are dominant factors that define protein stability. The role of surface residues in protein stability has received much less attention. It has been believed that surface residues are not important for protein stability particularly because their interactions with the solvent should be similar in the native and unfolded states. In the case of surface charged residues, it was sometimes argued that solvent exposure meant that the high dielectric of the solvent will further decrease the strength of the charge-charge interactions. In this paper, we challenge the notion that the surface charged residues are not important for protein stability. We computationally redesigned sequences of five different proteins to optimize the surface charge-charge interactions. All redesigned proteins exhibited a significant increase in stability relative to their parent proteins, as experimentally determined by circular dichroism spectroscopy and differential scanning calorimetry. These results suggest that surface charge-charge interactions are important for protein stability and that rational optimization of charge-charge interactions on the protein surface can be a viable strategy for enhancing protein stability.