沿着CTX-Mβ-lactamases反应坐标的结构,功能和抑制
Yu Chen1, Brian Shoichet, Richard Bonnet
1Department of Pharmaceutical Chemistry, University of California, San Francisco, Genentech Hall, 600 16th Street, San Francisco, California 94143-2240, USA.
Journal of the American Chemical Society
|April 14, 2005
概括
使用X射线结晶学研究CTX-M酶,这是抗生素耐药性的主要原因. 研究人员确定了关键的结构变化和一种新的抑制机制,为针对耐药细菌的新药设计铺平了道路.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 微生物学 微生物学
背景情况:
- CTX-M酶是扩展光谱β-乳酸酶 (ESBL) 的一个显著且不断增长的组.
- 这些酶赋予了对青素和各种世代的头素的耐药性.
- 有效的抑制剂和对CTX-M酶的详细机制理解是有限的.
研究的目的:
- 为了阐明CTX-M酶的详细机制.
- 使用X射线晶体学来描述酶的反应坐标.
- 为设计针对CTX-M介导抗生素耐药性的新型抑制剂提供结构模板.
主要方法:
- CTX-M酶的X射线晶体结构.
- 复杂的形成与过渡状态类似物和β-乳糖抑制剂.
- 对沿着反应坐标的酶形状变化的分析.
主要成果:
- 在催化残留物Lys73和Glu166.6中观察到的构造变化.
- 发现塞福西的7alpha-methoxy组通过硬质阻断脱来抑制,而不是通过取代催化水来抑制.
- 与CTX-M-16.1相比,鉴定了一种类似于ceftazidime的酸抑制剂,具有4nM K (i) 值.
- 在使用酸抑制剂的细菌中,证明逆转了塞福胺耐药性.
结论:
- 该研究提供了CTX-M酶机制的详细结构视图.
- 这些发现提供了针对CTX-M酶的抑制剂设计策略的见解.
- 结构数据可以指导开发针对CTX-M酶所赋予的抗生素耐药性的新干预措施.
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