在由催化抗体介导的反应中显著的远程性识别
Lawrence J D'Souza1, Benoît Gigant, Marcel Knossow
1Department of Pharmaceutical Chemistry, The Hebrew University, School of Pharmacy, P.O. Box 12065, Jerusalem 91120, Israel.
Journal of the American Chemical Society
|March 7, 2002
概括
催化抗体D2.3显示出对反体的显著反应性差异,尽管结合部位的结构变化很小. 蛋白质相互作用微妙地影响化学行为和结合亲和力.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 免疫学 免疫学 免疫学
背景情况:
- 催化抗体 (非酶) 是化学合成和生物研究中的强大工具.
- 了解abzyme特异性和反应性的结构基础对于蛋白质工程和药物设计至关重要.
研究的目的:
- 阐明催化抗体D2.3对两个反体的不同反应性的基础结构决定因素.
- 为了研究蛋白质-连接体相互作用和酶中的催化效率之间的关系.
主要方法:
- 采用X射线晶体学来确定催化抗体D2.3 Fab的高分辨率晶体结构,并与过渡状态模拟反体 (7D和7L) 复合.
- 测量了结合亲和力 (K(M)) 和催化速率 (k(cat)) 以量化反应性差异.
主要成果:
- 晶体结构显示,在抗体结合部位内,两种反体 (7D和7L) 的电子密度几乎相同.
- 尽管结构相似,但L-反体与D2.3.3具有显著更紧密的结合 (较低的K(M)) 和较高的催化活性 (较高的k(cat))
- 影响反应性的性中心被发现与抗体的催化中心相距很远 (7个键).
结论:
- 微妙的蛋白质-连接体相互作用,从静态电子密度图中不容易明显,显著影响抗体催化和结合.
- 这项研究强调了蛋白质结构和化学反应之间的复杂相互作用,即使对于遥远的性中心.
- 这些发现为抗体催化反应的机制提供了宝贵的见解,并为未来的蛋白质设计工作提供了信息.
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