Carbene in Cupredoxin Protein Scaffolds: Replacement of a Histidine Ligand in the Active Site Substantially Alters Copper Redox Properties
Carbene in Cupredoxin Protein Scaffolds: Replacement of a Histidine Ligand in the Active Site Substantially Alters Copper Redox Properties
复制标题
DOI：
10.1002/anie.201807168
复制
发表时间：
2018-08-13
影响因子：
16.6
通讯作者：
Albrecht, Martin
中科院分区：
文献类型：
--
作者：
Planchestainer, Matteo;Segaud, Nathalie;Albrecht, Martin
N-杂环卡宾（NHC）配体在均相催化中具有重要的影响，然而，它们在生物系统中的潜在作用基本上是未开发的。我们取代了铜配位组氨酸（His）的氧化还原酶天青蛋白的活性位点与外源性二甲基imidazolylidene。该NHC迅速恢复1型Cu中心，其光谱特性（EPR，UV/维斯）与野生型中His的N-配位的光谱特性相同。然而，NHC的引入显著改变了金属的氧化还原电位，这是这种蓝铜蛋白的关键功能。这些结果表明，组氨酸的C-键合是合理的，并在其（瞬态）活性状态的氧化还原活性金属酶的潜在相关的键合模式。
N-heterocyclic carbene (NHC) ligands have had a major impact in homogeneous catalysis, however, their potential role in biological systems is essentially unexplored. We replaced a copper-coordinating histidine (His) in the active site of the redox enzyme azurin with exogenous dimethyl imidazolylidene. This NHC rapidly restores the type-1 Cu center, with spectroscopic properties (EPR, UV/Vis) that are identical to those from N-coordination of the His in the wild type. However, the introduction of the NHC markedly alters the redox potential of the metal, which is a key functionality of this blue copper protein. These results suggest that C-bonding for histidine is plausible and a potentially relevant bonding mode of redox-active metalloenzymes in their (transient) active states.