...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Slow folding and assembly of a procaspase-3 interface variant
【24h】

Slow folding and assembly of a procaspase-3 interface variant

机译：procaspase-3接口变体的缓慢折叠和组装

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

Caspases execute apoptosis and exist in the cell as inactive zymogens (procaspases) prior to activation. Initiator procaspases are monomers that must dimerize for activation, while effector procaspases, such as procaspase-3, are stable dimers that must be processed for activation. The dimer interface regions of the two subfamilies are different, although the role of the interface in oligomerization is not known. Equilibrium and kinetic folding studies were performed on procaspase-3(C163S,V266H), an interface variant, to determine the importance of the dimer interface in the folding of procaspase-3. Equilibrium folding data at pH 5 and 7 display a hysteresis, indicating a kinetically controlled folding reaction. Refolding kinetic studies reveal a complex burst phase, followed by a series of monomeric intermediates. At longer refolding times, the monomer populates a species that becomes kinetically trapped and slowly aggregates. Unfolding kinetic studies reveal a hyperfluorescent native ensemble that unfolds to form highly structured monomeric intermediates that unfold very slowly. Dimerization is very slow, likely because of the inability to correctly orient the histidine residues in the interface, so the initial encounter complex for dimerization is inefficient. As a consequence, the monomer folds into species that aggregate. Introducing a histidine into the interface of procaspase-3 prevents activation by acting as a negative design element, providing evidence that the interface region is a site of regulation of caspase assembly in general by affecting the rate of dimerization.
机译：胱天蛋白酶执行凋亡，并在活化前以失活的酶原（蛋白酶）的形式存在于细胞中。引发剂procaspases是必须二聚才能激活的单体，而效应子procaspases（例如procaspase-3）是稳定的二聚体，必须对其进行加工才能激活。尽管尚不清楚该界面在低聚中的作用，但两个亚家族的二聚体界面区域是不同的。对procaspase-3（C163S，V266H）（一种界面变体）进行了平衡和动力学折叠研究，以确定二聚体界面在procaspase-3折叠中的重要性。 pH为5和7时的平衡折叠数据显示出滞后现象，表明动力学控制了折叠反应。复性动力学研究揭示了一个复杂的破裂相，随后是一系列单体中间体。在较长的重折叠时间下，单体填充的物质会被动力学捕获并缓慢聚集。展开动力学研究揭示了一种超荧光的天然集合体，其展开形成非常缓慢地展开的高度结构化的单体中间体。二聚化非常慢，这可能是由于无法正确定位界面中的组氨酸残基，因此用于二聚化的最初遇到的复合物效率低下。结果，单体折叠成聚集的物质。将组氨酸引入procaspase-3的界面可防止其通过充当负设计元素来激活，从而提供了证据表明该界面区域通常是通过影响二聚化速率来调节caspase装配的位点。

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