P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States.
P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States.
Methods Enzymol. 2021;650:19-55. doi: 10.1016/bs.mie.2021.01.037.
Historically, rare-earth ions have been considered irrelevant to biology. Recently, the active sites of certain methanol dehydrogenase (MDH) enzymes have been shown to contain a redox-inactive, rare-earth (RE) cation coordinated by the redox-active pyrroloquinoline quinone (PQQ) cofactor. Importantly, it was demonstrated that rare earths were essential for the growth of certain methylotrophs that incorporated the XoxF-MDH. In this chapter, we summarize the optimized synthesis of a previously published rare-earth complex that serves as a model of the active site of this RE-containing MDH enzyme. The structure and reactivity of the metalated complex, [La(L)(NO)] are also discussed. [La(L)(NO)] catalytically oxidizes the test alcohol substrate, p-methylbenzyl alcohol, BnOH, to p-methylbenzaldehyde, PhCHO, in the presence of a base (2,6-lutidine) and a terminal oxidant (ferrocenium hexafluorophosphate) with ~17 turnovers. By studying this synthetic model, we have developed a body of evidence about both the reactivity and the mechanism of dehydrogenation of alcohols as a molecular analogue to a native, rare-earth dependent enzyme.
从历史上看，稀土离子被认为与生物学无关。最近，某些甲醇脱氢酶（MDH）酶的活性部位被证明含有一个氧化还原非活性的、由氧化还原活性吡咯并喹啉醌（PQQ）辅因子配位的稀土（RE）阳离子。重要的是，已经证明稀土对于某些甲基营养生物的生长是必不可少的，这些生物含有 XoxF-MDH。在本章中，我们总结了先前发表的稀土配合物的优化合成，该配合物可作为含 RE 的 MDH 酶活性部位的模型。还讨论了金属化配合物[La(L)(NO)]的结构和反应性。[La(L)(NO)]在碱（2,6- 卢定）和末端氧化剂（六氟磷酸铁）存在下，催化氧化测试醇底物 p-甲基苄醇，BnOH，生成 p-甲基苯甲醛，PhCHO，具有约 17 个周转率。通过研究这个合成模型，我们已经积累了关于醇的反应性和脱氢机制的证据，作为天然的、依赖稀土的酶的分子类似物。
