漆酶（EC1.10.3.2）能够催化多种底物发生氧化，是高效的多功能生物催化剂，在环保、医药、纺织和食品加工等领域有广泛应用价值。但漆酶应用的推进迫切需要提高其在高盐/卤素离子等环境下的催化效率。植物和真菌漆酶的催化活性易受卤素离子抑制，某些细菌漆酶能耐受高浓度的盐，少数细菌漆酶的催化活性在一定浓度盐存在下还得到提升，细菌漆酶的这种嗜卤素离子性质对于漆酶的理论研究和实践应用都有重要意义，但目前对其嗜卤素离子机制的研究还未见报道。在前期工作中，本研究组发现海洋细菌漆酶Lac15具有优越的嗜/耐卤素离子特性，本项目拟以Lac15为研究对象，利用圆二色谱、荧光光谱和X-射线晶体解析等技术，结合热变性或化学变性以及定点突变等方法，通过考察酶的结构及其稳定性，以及相关质子/电子传递活性位点等与酶嗜卤素离子性质的关系，从生化和结构角度对其嗜卤素离子机制进行研究，为漆酶性质及其应用的理论和实践做出贡献。

Laccases (EC 1.10.3.2), multifunctional biocatalysts that catalyse oxidation of diverse substrates, have potential applications in many industries such as environment protection, medicine, textile and food. For application purposes, it is urgent to promote laccase activities under high concentrations of halides and/or salts. Typical laccases from plants and fungi easily lose activities upon exposure to halides/salts, whereas a few bacterial laccases tolerate and are even activated by high concentrations of halides/salts. Exploring the mechanisms underlying the halophilic character of laccases will be helpful to accelerate the process of laccases from theoretical study to industrial applications. Our pioneer work discovered a marine bacterial laccase (Lac15) with excellent halides/salts-tolerant ability. In the present application, we propose to use Lac15 as a model to investigate the halophilic mechanism of laccases. Lac15 will be subject to diverse assays including heat/chemical denaturation, site mutation, circular dichroism spectrum, fluorescence spectrum and 3-D crystallographic structure. It is anticipated to obtain key enzymatic parameters to elucidate the relationship of enzyme stability, 3-D structure, amino acid residues and the active site of electron transportation with the halophilic characters of laccases. Successful completion of the present program will guide development of laccases suitable for industrial applications.