芳香胺N-乙酰转移酶（NAT）通过N-乙酰化或者O-乙酰化修饰芳香胺，分别对芳香胺类化合物的降毒或者活化起到重要作用。NAT、转谷氨酰胺酶和半胱氨酸蛋白酶结构和功能差异巨大，但是三者均含有一个严格保守的Cys-His-Asp/Asn催化三联体。项目通过比较三种酶的催化核心结构，在活性中心附近发掘三者的空间位置保守残基，并研究其在NAT催化中的作用机制。项目拟通过酶动力学研究该空间保守残基对NAT酶催化的过渡态和底物结合的影响，进一步通过晶体结构、分子动力学模拟探索该位置在NAT催化中与底物的具体相互作用。通过进化耦合分析和网络分析探索多态性位点与空间保守位点协同调控NAT的催化机理，采用定点突变和酶动力学验证。本课题在理论上将进一步加深对NAT催化机制的认识，在实践中对基于NAT的药物理性设计，以及针对NAT的酶工程提供理论指导。

Arylamine N-acetyltransferases (NATs) exert important function in detoxification and bioactivation of arylamines through N-acetylation and O-acetylation respectively. The NAT, transglutaminase and cysteine protease are remarkably different in their structures and function, however they share a strictly conserved Cys-His-Asp/Asn catalytic triad. Comparing the core structures of the three family enzymes, this project tries to discover spatial conserved residue close to the catalytic triad, and to investigate the catalytic mechanism on NAT. Thus the transient state and substrate binding will be evaluated by NAT enzymatic kinetics. Combining crystal structure and molecular dynamic simulation, we will study the interaction details between substrates and NAT. In addition, through statistical coupling analysis and network analysis, the coregulation on NAT catalytic mechanism by polymorphic sites and spatial conserved residue will be explorered, which will be confirmed by site-directed mutation and enzyme kinetics. In theory, this project will extend the understanding of NAT catalysis, while in practice, the study will provide the theory guidance on the drug design and enzyme enineering based on NAT.