文献类型：期刊文献

英文题名：Increased surface charge in the protein chaperone Spy enhances its anti-aggregation activity

作者：He, Wei[1];Zhang, Jiayin[1];Sachsenhauser, Veronika[2];Wang, Lili[2];Bardwell, James C. A.[2];Quan, Shu[1]

机构：[1]East China Univ Sci & Technol, Shanghai Collaborat Innovat Ctr Biomfg, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[2]Univ Michigan, Howard Hughes Med Inst, Dept Mol Cellular & Dev Biol, Ann Arbor, MI 48109 USA

年份：2020

卷号：295

期号：42

起止页码：14488

外文期刊名：JOURNAL OF BIOLOGICAL CHEMISTRY

收录：;EI(收录号：20204909587859);WOS:【SCI-EXPANDED(收录号:WOS:000586428700019)】；

基金：This work was supported by the National Natural Science Foundation of China Grants 31661143021 and 31400664 (to S. Q.), the Fundamental Research Funds for the Central Universities Grant 22221818014 (to S. Q.), and the Research Program of State Key Laboratory of Bioreactor Engineering (to S. Q.).

语种：英文

外文关键词：molecular chaperone; Spy; protein engineering; protein aggregation; electrostatic interaction; hydrophobic interaction; kinetics; protein folding; conformational change; chaperone-substrate interaction

摘要：Chaperones are essential components of the protein homeostasis network. There is a growing interest in optimizing chaperone function, but exactly how to achieve this aim is unclear. Here, using a model chaperone, the bacterial protein Spy, we demonstrate that substitutions that alter the electrostatic potential of Spy's concave, client-binding surface enhance Spy's anti-aggregation activity. We show that this strategy is more efficient than one that enhances the hydrophobicity of Spy's surface. Our findings thus challenge the traditional notion that hydrophobic interactions are the major driving forces that guide chaperone-substrate binding. Kinetic data revealed that both charge- and hydrophobicity-enhanced Spy variants release clients more slowly, resulting in a greater "holdase" activity. However, increasing short-range hydrophobic interactions deleteriously affected Spy's ability to capture substrates, thus reducing its in vitro chaperone activity toward fast-aggregating substrates. Our strategy in chaperone surface engineering therefore sought to fine-tune the different molecular forces involved in chaperone-substrate interactions rather than focusing on enhancing hydrophobic interactions. These results improve our understanding of the mechanistic basis of chaperone-client interactions and illustrate how protein surface-based mutational strategies can facilitate the rational improvement of molecular chaperones.