• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Constraining enzyme conformational change by an antibody leads to hyperbolic inhibition.
【24h】

Constraining enzyme conformational change by an antibody leads to hyperbolic inhibition.

机译：抗体限制酶构象变化导致双曲线抑制。

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

Although it has been known for many years that antibodies display properties characteristic of allosteric effectors, the molecular mechanisms responsible for these effects remain poorly understood. Here, we describe a single-domain antibody fragment (nanobody) that modulates protein function by constraining conformational change in the enzyme dihydrofolate reductase (DHFR). Nanobody 216 (Nb216) behaves as a potent allosteric inhibitor of DHFR, giving rise to mixed hyperbolic inhibition kinetics. The crystal structure of Nb216 in complex with DHFR reveals that the nanobody binds adjacent to the active site. Half of the epitope consists of residues from the flexible Met20 loop. This loop, which ordinarily oscillates between occluded and closed conformations during catalysis, assumes the occluded conformation in the Nb216-bound state. Using stopped flow, we show that Nb216 inhibits DHFR by stabilising the occluded Met20 loop conformation. Surprisingly, kinetic data indicate that the Met20 loop retains sufficient conformational flexibility in the Nb216-bound state to allow slow substrate turnover to occur.
机译：尽管多年以来已知抗体显示出变构效应子的特性，但是引起这些效应的分子机制仍然知之甚少。在这里，我们描述了通过限制酶二氢叶酸还原酶（DHFR）的构象变化来调节蛋白质功能的单域抗体片段（纳米抗体）。纳米抗体216（Nb216）充当DHFR的有效变构抑制剂，从而产生混合双曲线抑制动力学。 Nb216与DHFR形成复合物的晶体结构表明，纳米抗体在活性位点附近结合。表位的一半由柔性Met20环的残基组成。该环通常在催化过程中在闭合构象和闭合构象之间振荡，并假定该闭合构象处于结合Nb216的状态。使用停止流，我们显示Nb216通过稳定闭塞的Met20环构象来抑制DHFR。出人意料的是，动力学数据表明，Met20环在Nb216-结合状态下保留了足够的构象柔性，以允许发生缓慢的底物周转。

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