The molecular chaperone Hsp33 is activated by atmospheric-pressure plasma protecting proteins from aggregation
The molecular chaperone Hsp33 is activated by atmospheric-pressure plasma protecting proteins from aggregation
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DOI：
10.1098/rsif.2018.0966
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发表时间：
2019-06-01
影响因子：
3.9
通讯作者：
Bandow, Julia E.
中科院分区：
文献类型：
--
作者：
Krewing, Marco;Stepanek, Jennifer Janina;Bandow, Julia E.
非平衡大气压等离子体是灭菌和消毒的替代手段。血浆介导的蛋白质聚集已被确定为负责血浆的抗菌特征的机制之一。热休克蛋白33（Heat shock protein 33，Hsp33）是一种具有保持酶功能的分子伴侣，在氧化应激和解折叠条件同时发生时被激活。在其活性形式中，它结合未折叠的蛋白质并防止其聚集。在这里，我们分析了等离子体对大肠杆菌热休克蛋白33的结构和功能的影响，使用介质阻挡放电等离子体。虽然迄今为止研究的大多数其他蛋白质被大气压等离子体迅速灭活，但暴露于等离子体激活了Hsp33。在等离子体处理后，观察到半胱氨酸残基的氧化和热休克蛋白33的部分解折叠。血浆介导的热休克蛋白33的激活是可逆的还原剂，表明半胱氨酸残基的调节热休克蛋白33 activitynot不可逆氧化。然而，减少产生的蛋白质没有恢复其原始折叠。然而，第二轮等离子体处理再次产生完全活性的蛋白质，其解折叠程度甚至更高。这些构象状态以前没有观察到化学活化后与HOCl。因此，虽然我们可以检测到在等离子体处理过程中的液相中的HOCl的形成，我们得出结论，其他物种必须参与血浆激活的Hsp33。E.当用血浆处理时，从质粒过表达Hsp33编码基因hslO的大肠杆菌细胞显示增加的存活率，而hslO缺失突变体是高度敏感的，强调了蛋白质聚集作为血浆失活机制的重要性。
Non-equilibrium atmospheric-pressure plasmas are an alternative means to sterilize and disinfect. Plasma-mediated protein aggregation has been identified as one of the mechanisms responsible for the antibacterial features of plasma. Heat shock protein 33 (Hsp33) is a chaperone with holdase function that is activated when oxidative stress and unfolding conditions coincide. In its active form, it binds unfolded proteins and prevents their aggregation. Here we analyse the influence of plasma on the structure and function of Hsp33 of Escherichia coli using a dielectric barrier discharge plasma. While most other proteins studied so far were rapidly inactivated by atmospheric-pressure plasma, exposure to plasma activated Hsp33. Both, oxidation of cysteine residues and partial unfolding of Hsp33 were observed after plasma treatment. Plasma-mediated activation of Hsp33 was reversible by reducing agents, indicating that cysteine residues critical for regulation of Hsp33 activitywere not irreversibly oxidized. However, the reduction yielded a protein that did not regain its original fold. Nevertheless, a second round of plasma treatment resulted again in a fully active protein that was unfolded to an even higher degree. These conformational states were not previously observed after chemical activation with HOCl. Thus, although we could detect the formation of HOCl in the liquid phase during plasma treatment, we conclude that other species must be involved in plasma activation of Hsp33. E. coli cells over-expressing the Hsp33-encoding gene hslO from a plasmid showed increased survival rates when treated with plasma while an hslO deletion mutant was hypersensitive emphasizing the importance of protein aggregation as an inactivation mechanism of plasma.