Copper-oxygen Dynamics in Tyrosinase Mechanism.
Copper-oxygen Dynamics in Tyrosinase Mechanism.
复制标题
酪氨酸酶机制中的铜氧动力学。
作者：
N. Fujieda;K. Umakoshi;Yuta Ochi;Y. Nishikawa;S. Yanagisawa;M. Kubo;G. Kurisu;S. Itoh
双核铜酶酪氨酸酶激活O2以形成（μ-η2：η2-过氧化物基）二铜（II）物质，其将酚羟基化为儿茶酚。然而，在酪氨酸酶催化位点的酚酶反应的确切机制仍然存在争议。本文报道了以L-酪氨酸为底物的活性酪氨酸酶的近原子分辨率X射线晶体结构。在它们的催化位点，CuA主要向L-酪氨酸（CuA 1到CuA 2）移动，其酚氧直接与CuA 2配位，涉及CuB的移动（CuB 1到CuB 2）。双氧结合酪氨酸酶的晶体结构和光谱分析表明，过氧化物配体旋转，自发地削弱其O-O键。因此，由底物结合诱导的铜迁移伴随着结合的过氧化物物种的重排，以便于其中一个过氧化物氧原子接近苯酚底物的ε碳原子。
The dinuclear copper enzyme tyrosinase activates O2 to form a (μ-η2:η2-peroxido)dicopper(II) species, which hydroxylates phenols to catechols. However, the exact mechanism of phenolase reaction in the catalytic site of tyrosinase is still under debate. We herein report the near atomic resolution X-ray crystal structures of the active tyrosinases with substrate L-tyrosine. At their catalytic sites, CuA moved largely toward L-tyrosine (CuA1 to CuA2), whose phenol oxygen directly coordinates to CuA2, involving the movement of CuB (CuB1 to CuB2). The crystal structures and spectroscopic analyses of the dioxygen-bound tyrosinases demonstrated that the peroxide ligand rotated, spontaneously weakening its O-O bond. Thus, the copper migration induced by the substrate-binding accompanied rearrangement of the bound peroxide species so as to facilitate one of the peroxide oxygen atoms to access to the phenol substrate's ε carbon atom.
DOI：
10.1073/pnas.1302144110
发表时间：
2013-07-30
影响因子：
11.1
作者：
Jeoung, Jae-Hun;Bommer, Martin;Dobbek, Holger
通讯作者：
Dobbek, Holger
影响因子：
62.1
作者：
Solomon, Edward I.;Heppner, David E.;Johnston, Esther M.;Ginsbach, Jake W.;Cirera, Jordi;Qayyum, Munzarin;Kieber-Emmons, Matthew T.;Kjaergaard, Christian H.;Hadt, Ryan G.;Tian, Li
通讯作者：
Tian, Li