Continuous Wave Photolysis Magnetic Field Effect Investigations with Free and Protein-Bound Alkylcobalamins
Continuous Wave Photolysis Magnetic Field Effect Investigations with Free and Protein-Bound Alkylcobalamins
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DOI：
10.1021/ja9059238
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发表时间：
2009-12-02
影响因子：
15
通讯作者：
Scrutton, Nigel S.
中科院分区：
文献类型：
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作者：
Jones, Alex R.;Woodward, Jonathan R.;Scrutton, Nigel S.
腺苷钴胺依赖酶中Co-C键的激活产生单胎Co-II-腺苷自由基对。关于这一过程的两个突出问题是：(1)这类酶获得显著的均质裂解速率的来源是什么？(2)生成的自由基对的反应动力学对外部磁场的应用敏感吗？在这里，我们提供了连续波光解磁场效应(MFE)数据，揭示了乙醇胺氨解酶(EAL)活性位置是观察腺苷钴胺自由基对增强的磁场敏感性的理想微反应器。观察到的场依赖关系与由已发表的组成基超精细耦合计算的场依赖关系非常一致，并且MFE的大小(
The activation of the Co-C bond in adenosylcobalamin-dependent enzymes generates a singletborn Co-II-adenosyl radical pair. Two of the salient questions regarding this process are: (1) What is the origin of the considerable homolysis rate enhancement achieved by this class of enzyme? (2) Are the reaction dynamics of the resultant radical pair sensitive to the application of external magnetic fields? Here, we present continuous wave photolysis magnetic field effect (MFE) data that reveal the ethanolamine ammonia lyase (EAL) active site to be an ideal microreactor in which to observe enhanced magnetic field sensitivity in the adenosylcobalamin radical pair. The observed field dependence is in excellent agreement with that calculated from published hyperfine couplings for the constituent radicals, and the magnitude of the MFE (