Jia-Ying Xin, Chun-Yu Li, Shuai Zhang, Yan Wang, Wei Zhang, Chun-Gu Xia
State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
Key Laboratory for Food Science and Engineering, Harbin University of Commerce, Harbin 150076, People's Republic of China.
IET Nanobiotechnol. 2018 Oct;12(7):915-921. doi: 10.1049/iet-nbt.2018.0069.
Methanobactin (Mb) is a small copper-chelating molecule that functions as an agent for copper acquisition, uptake and copper-containing methane monooxygenase catalysis in methane-oxidising bacteria. The UV-visible spectral and fluorescence spectral suggested that Mb/Cu coordination complex as a monomer (Mb-Cu), dimmer (Mb-Cu) and tetramer (Mb-Cu) could be obtained at different ratios of Mb to Cu (II). The kinetics of the oxidation of hydroquinone with hydrogen peroxide catalysed by the different Mb/Cu coordination complex were investigated. The results suggested that Mb-Cu coordination form has highest catalytic capacity. Further, Mb-modified gold nanoparticles (AuNPs) were obtained by ligand exchange and assembled into two- and three-D nanocluster structure by metal-organic coordination as driving force. It has been found that AuNPs increased the catalytic activity of Mb-Cu on AuNPs. The more significant catalytic activity was exhibited by the nanocluster assembly with multi-catalytic centres. This may be attributed to the multivalent collaborative characteristics of the catalytic active centres in the nanocluster network assembly. The assembly of Mb-modified AuNPs can act as excellent nanoenzyme models for imitating peroxidase.
甲醇菌素（Mb）是一种小分子铜螯合分子，在甲烷氧化细菌中作为获取铜、摄取铜以及含铜甲烷单加氧酶催化作用的介质。紫外可见光谱和荧光光谱表明，在不同的Mb与铜（II）比例下，可以得到单体（Mb-Cu）、二聚体（Mb₂-Cu）和四聚体（Mb₄-Cu）形式的Mb/Cu配位络合物。研究了不同Mb/Cu配位络合物催化过氧化氢氧化对苯二酚的动力学。结果表明，Mb-Cu配位形式具有最高的催化能力。此外，通过配体交换获得了Mb修饰的金纳米颗粒（AuNPs），并以金属有机配位为驱动力组装成二维和三维纳米簇结构。研究发现，AuNPs提高了Mb-Cu在AuNPs上的催化活性。具有多催化中心的纳米簇组装表现出更显著的催化活性。这可能归因于纳米簇网络组装中催化活性中心的多价协同特性。Mb修饰的AuNPs组装体可以作为模拟过氧化物酶的优良纳米酶模型。
