Tryptophan Lyase (NosL): A Cornucopia of 5′-Deoxyadenosyl Radical Mediated Transformations
Tryptophan Lyase (NosL): A Cornucopia of 5′-Deoxyadenosyl Radical Mediated Transformations
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DOI：
10.1021/jacs.6b06139
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发表时间：
2016-12-21
影响因子：
15
通讯作者：
Begley, Tadhg P.
中科院分区：
文献类型：
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作者：
Bhandari, Dhananjay M.;Fedoseyenko, Dmytro;Begley, Tadhg P.
色氨酸裂解酶（NosL）是一种自由基S-腺苷-L-甲硫氨酸（SAM）酶，催化L-色氨酸形成3-甲基-2-吲哚酸。在本文中，我们证明，S '-脱氧腺苷自由基是相当多的比以前预期的更灵活的化学：从N-α-cydopropyltryptophan的氢原子提取发生在C α，而不是氨基与NosL Y 90 A和取代底物胺与酮或烯烃的化学变化从氢原子提取双键加成。此外，5 '-脱氧腺苷自由基可以加入到[4Fe-4S]簇中，并且连二亚硫酸盐可以用于在活性位点捕获自由基。
Tryptophan lyase (NosL) is a radical S-adenosyl-L-methionine (SAM) enzyme that catalyzes the formation of 3-methyl-2-indolic acid from L-tryptophan. In this paper, we demonstrate that the S'-deoxyadenosyl radical is considerably more versatile in its chemistry than previously anticipated: hydrogen atom abstraction from N-alpha-cydopropyltryptophan occurs at C alpha rather than the amino group with NosL Y90A and replacing the substrate amine with a ketone or an alkene changes the chemistry from hydrogen atom abstraction to double bond addition. In addition, the 5'-deoxyadenosyl radical can add to the [4Fe-4S] cluster and dithionite can be used to trap radicals at the active site.