Specific Ion Effects on Protein Thermal Aggregation from Dilute Solutions to Crowded Environments
Specific Ion Effects on Protein Thermal Aggregation from Dilute Solutions to Crowded Environments
复制标题
从稀溶液到拥挤环境的特定离子对蛋白质热聚集的影响
DOI：
10.1021/acs.langmuir.8b00294
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发表时间：
2018
期刊：
影响因子：
3.9
通讯作者：
Liu Guangming
中科院分区：
文献类型：
--
作者：
Li Shuling;Ye Shuji;Liu Guangming
我们研究了从稀溶液到拥挤环境中特定离子对蛋白质热聚集的影响。分别以卵清蛋白和聚乙二醇作为模型蛋白和拥堵剂。我们的研究表明，当溶液条件从稀溶液变为拥挤环境时，卵清蛋白热聚集的限速步骤从未折叠的蛋白质分子的聚集转变为蛋白质分子的解折叠。共沸离子和共沸离子对卵清蛋白热聚集的影响是不同的。在稀溶液中，亲水性阴离子通过增加蛋白质疏水相互作用促进卵清蛋白分子的热聚集。相反，在拥挤的环境中，通过加速蛋白质分子的展开，杂乱离子促进了卵清蛋白的热聚集。因此，在稀溶液和拥挤环境中，有不同的机制导致蛋白质热聚集的离子特异性。蛋白质分子之间的离子特异性疏水相互作用和蛋白质分子在稀溶液和拥挤环境中的离子特异性展开分别主导着离子的特异性。
We have investigated specific ion effects on protein thermal aggregation from dilute solutions to crowded environments. Ovalbumin and poly(ethylene glycol) have been employed as the model protein and crowding agent, respectively. Our studies demonstrate that the rate-limiting step of ovalbumin thermal aggregation is changed from the aggregation of unfolded protein molecules to the unfolding of the protein molecules, when the solution conditions are varied from a dilute solution to a crowded environment. The specific ion effects acting on the thermal aggregation of ovalbumin generated by kosmotropic and chaotropic ions are different. The thermal aggregation of ovalbumin molecules is promoted by kosmotropic anions in dilute solutions via an increase in protein hydrophobic interactions. In contrast, ovalbumin thermal aggregation is facilitated by chaotropic ions in crowded environments through accelerated unfolding of protein molecules. Therefore, there are distinct mechanisms causing the ion specificities of protein thermal aggregation between dilute solutions and crowded environments. The ion specificities are dominated by ion-specific hydrophobic interactions between protein molecules and ion-specific unfolding of protein molecules in dilute solutions and crowded environments, respectively.