Increased Efficiency of GroE-assisted Protein Folding by Manganese Ions (*)
Increased Efficiency of GroE-assisted Protein Folding by Manganese Ions (*)
复制标题
通过锰离子提高 GroE 辅助蛋白质折叠的效率 (*)
DOI：
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发表时间：
1995
影响因子：
4.8
通讯作者：
P. Goloubinoff
中科院分区：
文献类型：
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作者：
S. Diamant;A. Azem;C. Weiss;P. Goloubinoff
本研究探讨了ATP结合和游离的Mg 2+和Mn 2+离子在脲变性苹果酸脱氢酶分子伴侣辅助复性的激活和调节中的作用。与Mg ~（2+）相比，Mn ~（2+）使GroE辅助的苹果酸脱氢酶复性速率显著增加，同时使ATP水解速率降低。此外，Mn 2+增加GroES对GroEL的亲和力，即使在饱和量的Mg 2+存在下。化学交联表明，与Mg-ATP相比，需要更低浓度的Mn-ATP来形成不对称的GroEL 14 GroES 7和对称的GroEL 14（GroES 7）2颗粒。蛋白质折叠速率的锰依赖性增加与伴侣蛋白溶液中检测到的对称GroEL 14（GroES 7）2颗粒的量的特定增加一致。因此，Mn 2+是一个辅因子，可以显着增加伴侣蛋白反应的效率在体外。Mn ~（2+）离子可作为分析伴侣蛋白分子机制和结构的重要工具。
This study addresses the role of ATP-bound and free Mg2+ and Mn2+ ions in the activation and modulation of chaperonin-assisted refolding of urea-denatured malate dehydrogenase. As compared with Mg2+, Mn2+ ions caused a significant increase in the rate of GroE-assisted malate dehydrogenase refolding and, concomitantly, a decrease in the rate of ATP hydrolysis. Moreover, Mn2+ increases the affinity of GroES for GroEL, even in the presence of saturating amounts of Mg2+. Chemical cross-linking showed that lower concentrations of Mn-ATP as compared with Mg-ATP are needed to form both asymmetric GroEL14GroES7 and symmetric GroEL14(GroES7)2 particles. The manganese-dependent increase in the rate of protein folding concurred with a specific increase in the amount of symmetric GroEL14(GroES7)2 particles detected in a chaperonin solution. Thus, Mn2+ is a cofactor that can markedly increase the efficiency of the chaperonin reaction in vitro. Mn2+ ions can serve as an important tool for analyzing the molecular mechanism and the structure of chaperonins.