Catalytic turnover of benzylamine by a model for the lysine tyrosylquinone (LTQ) cofactor of lysyl oxidase.
Catalytic turnover of benzylamine by a model for the lysine tyrosylquinone (LTQ) cofactor of lysyl oxidase.
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DOI：
10.1021/ja011141j
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发表时间：
2001-09
影响因子：
15
通讯作者：
K. Ling;J. Kim;L. Sayre
中科院分区：
文献类型：
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作者：
K. Ling;J. Kim;L. Sayre
赖氨酰氧化酶与其他铜胺氧化酶的不同之处在于，其活性醌辅因子反映了赖氨酰残基与血浆和其他铜胺氧化酶中发现的酪氨酸衍生的醌核的交联。合成了赖氨酰氧化酶辅因子（LTQ）的模型，即3，3-二甲基-2，3-二氢吲哚-5，6-醌（4），发现其对水解和氧化事件均稳定，从而阻止了更简单的模型作为周转催化剂。我们发现，4催化的苄胺的有氧氧化脱氨基，虽然营业额最终停止考虑到氧化的二氢苯并恶唑互变异构体的“产品希夫碱”，形成苯并恶唑，反应，可能是生理相关的。通过结合光学和NMR光谱和O（2）吸收研究阐明了整体反应曲线的机制。
Lysyl oxidase differs from other copper amine oxidases in that its active quinone cofactor reflects cross-linking of a lysyl residue into the tyrosine-derived quinone nucleus found in the plasma and other copper amine oxidases. A model for the lysyl oxidase cofactor (LTQ), 3,3-dimethyl-2,3-dihydroindole-5,6-quinone (4), was synthesized and found to be stable to both hydrolysis and oxidation events that prevent simpler models from functioning as turnover catalysts. We show that 4 catalyzes the aerobic oxidative deamination of benzylamine, though turnover eventually ceases on account of oxidation of the dihydrobenzoxazole tautomer of the "product Schiff base" to form a benzoxazole, a reaction that may be physiologically relevant. The mechanism of the overall reaction profile was elucidated by a combination of optical and NMR spectroscopy and O(2) uptake studies.