The Selective Reaction Mechanism of Halogenase SyrB2: A QM/MM Study

• 作 者: JingHuang[1]ChunsenLi[2]WeiWu[1]SasonShaik[3]
• 机 构: The State Key Laboratory of Physical Chemistry of Solid Surfaces,Fujian Provincial Key Laboratory of
• 出 处: 第十二届全国量子化学会议
• 发表日期: 2014年期

　　The catalytic cycle of α-ketoglutarate(α-KG)dependent non-heme Fe(II)halogenase SyrB2 was studied by hybrid QM/MM approach.Our results show that with the native substrate(L-Thr),only the quintet spin state contributes to O2 activation and substrate halogenation due to the exchange-enhanced reactivity(EER)in non-heme enzyme.The hydroxylation/halogenation selectivity is identified in this work by considering the external protein environments.The hydrogen bonding effects by the polar amino acids around the active site and substrate play the dominant role in stabilizing the transition state of the halogenation relative to hydroxylation.As such,SyrB2 exhibits exclusively the halogenation selectivity.