Angewandte Chemie International Edition, 1 March, 2021, DOI：https://doi.org/10.1002/anie.202016880
A genetically encoded two dimensional infrared probe for enzyme active‐site dynamics
Jiangyun Wang, Li Wang, Jia Zhang, Ming-Jie Han, Lu Zhang, Chao Chen, Aiping Huang, Ruipei Xie, Guosheng Wang, Jiangrui Zhu, Yuchuan Wang, Xiaohong Liu, Wei Zhuang, Yunliang Li
While two dimensional infrared (2D‐IR) spectroscopy is uniquely suitable for monitoring fs‐ps water dynamics around static protein structures, its utility for probing enzyme active‐site dynamics is limited, due to the lack of site‐specific 2D‐IR probes. In this work, we demonstrate the genetic incorporation of a novel 2D‐IR probe, m‐azido‐tyrosine (N3Y) in the active‐site of DddK, an iron dependent enzyme which catalyzes the conversion of dimethylsulfoniopropionate to dimethylsulphide. Our results show that both the oxidation of active‐site iron to Fe(III), and the addition of denaturation reagents result in significant decrease in enzyme activity, and active‐site water motion confinement. As tyrosine residues play important roles including general acid, general base, and electron transfer in many key enzymes, the genetically encoded 2D‐IR probe N3Y should be broadly applicable to investigate how the enzyme active‐site motions at fs‐ps time scale direct reactions pathways to facilitating specific chemical reactions.