由非传统的S-腺胺基酶形成的有机金属复合物
Min Dong1, Masaki Horitani2, Boris Dzikovski1
1Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
Journal of the American Chemical Society
|July 29, 2016
概括
Pyrococcus horikoshii Dph2酶可以分裂一个新的类似物, 显示出一个独特的有机金属复合物. 这一发现有助于理解激进的S-腺甲酶机制和铁-硫反应.
科学领域:
- 生物化学
- 酵素学
- 结构生物学
背景情况:
- Pyrococcus horikoshii Dph2 (PhDph2) 是一种激进的S-腺甲 (SAM) 酶.
- 它在二甲胺生物合成的初始步骤中起着至关重要的作用.
- PhDph2催化SAM裂变,形成一个3-氨基-3-基 (ACP) 基.
研究的目的:
- 研究PhDph2的反应机制.
- 阐明在SAM模拟裂变过程中形成的磁性物种的性质.
- 了解酶的 [4Fe-4S] 集群和反应产物之间的相互作用.
主要方法:
- 合成一种新型的SAM类似物 (SAMCA) 与3基基.
- 用PHDph2进行SAMCA的酶分裂.
- 使用同位素标记的SAMCA进行电子核双共振 (ENDOR) 光谱.
主要成果:
- 通过PHDph2分裂SAMCA,产生一个超磁性 (S=1/2) 物种.
- 这种物种被确定为α-硫-3-酸和4Fe-4S集群之间的复合物.
- ENDOR数据证实了和 [4Fe-4S] 集群的独特铁之间的π复合物.
结论:
- 这项研究提供了与SAM相关的 [4Fe-4S](+) 集群的第一个例子,该集群与基形成了有机金属复合物.
- 这些发现为PhDph2的催化机制提供了新的见解.
- 这些结果扩展了 SAM 激素酶中已知的 [4Fe-4S] 集群的反应模式.
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