...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Chaperonin Chamber Accelerates Protein Folding Through Passive Action Of Preventing Aggregation
【24h】

Chaperonin Chamber Accelerates Protein Folding Through Passive Action Of Preventing Aggregation

机译：伴侣室通过防止聚集的被动作用加速蛋白质折叠

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The original experiments reconstituting GroEL-GroES-mediated protein folding were carried out under "nonpermissive" conditions, where the chaperonin system was absolutely required and substrate proteins could not achieve the native state if diluted directly from denaturant into solution. Under "permissive" conditions, however, employing lower substrate concentration and lower temperature, some substrate proteins can be refolded both by the chaperonin system and while free in solution. For several of these, the protein refolds more rapidly inside the GroEL-GroES cis chamber than free in solution, suggesting that the chamber may have an active role in assisting protein folding. Here, we observe that the difference is caused by reversible multimolecular association while folding in solution, an avenue of kinetic partitioning that slows the overall rate of renaturation relative to the chaperonin chamber, where such associations cannot occur. For Rubisco, reversible aggregation during folding in solution was observed by gel filtration. For a mutant of maltose-binding protein (DM-MBP), the rate of folding in solution declined with increasing concentration, and the folding reaction produced light scattering. Under solution conditions where chloride was absent, however, light scattering no longer occurred, and DM-MBP folded at the same rate as in the cis cavity. In a further test, dihydrofolate reductase, thermally inactivated in the cis cavity or in solution, was substantially reactivated upon temperature downshift in the cis cavity but not in solution, where aggregation occurred. We conclude that the GroEL-GroES chamber behaves as a passive "Anfin-sen cage" whose primary role is to prevent multimolecular association during folding.
机译：重组GroEL-GroES介导的蛋白质折叠的原始实验是在“非许可”条件下进行的，其中绝对需要伴侣蛋白系统，并且如果直接从变性剂稀释到溶液中，底物蛋白质将无法达到天然状态。但是，在“允许的”条件下，采用较低的底物浓度和较低的温度，一些底物蛋白既可以通过伴侣蛋白系统重新折叠，也可以在溶液中游离。对于其中的几种，蛋白质在GroEL-GroES顺式腔室内的重折叠比在溶液中自由释放的快，这表明该腔室可能在协助蛋白质折叠中起积极作用。在这里，我们观察到差异是由于在溶液中折叠时可逆的多分子缔合引起的，这是一种动力学分配的途径，相对于分子伴侣腔（其中这种缔合不会发生），它降低了复性的总体速率。对于Rubisco，通过凝胶过滤观察到在溶液中折叠期间可逆的聚集。对于麦芽糖结合蛋白（DM-MBP）的突变体，溶液中的折叠速率随浓度的增加而降低，并且折叠反应产生光散射。但是，在没有氯化物的溶液条件下，不再发生光散射，并且DM-MBP以与顺式腔相同的速率折叠。在进一步的测试中，在顺式腔中或溶液中热灭活的二氢叶酸还原酶在顺式腔中温度下降时实质上重新活化，但在溶液中却没有聚集，而在溶液中发生聚集。我们得出的结论是，GroEL-GroES腔室表现为被动的“ Anfin-sen笼”，其主要作用是防止折叠过程中的多分子缔合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号