Catalytic performance and interaction mechanism of immobilized C-C bond hydrolase based on carbon nanotube
Carbon nanotube has been proved as a kind of novel support for enzyme immobilization.In this study,we performed a series of experiments to find the relationship between protein conformation and catalytic performance,using different carbon nanotubes (SWCNT and MWCNT),immobilize methods (physical adsorption and covalent binding) and C-C bond hydrolases (BphD and MfphA).The results showed that catalytic performance of immobilized enzyme depends on specific enzyme,immobilization method and type of carbon nanotube.Immobilized BphD based on chemical modified SWCNT (BphD-CSWCNT) has the highest activity and exhibited a comparable catalytic efficiency with free BphD (92.g%).However,when MfphA bound to pristine SWCNT (MfphA-SWCNT),it lost activity completely.Time-resolved fluorescence spectrum indicated static ground complexes formed during all of the immobilization processes.Circular dichroism (CD) of immobilized enzymes showed that the secondary structures changed in varying degrees.In order to investigate the inhibition mechanism of SWCNT on MfphA,we used molecular dynamics simulation of SWCNT-MfphA conjugate to analyze the adsorption process,binding sites and time evolution of substrate tunnels.The results indicated that the preference binding sites (Trp201 and Met81) blocked the main tunnel of MfphA,which can be a novel possible inhibition mechanism for enzyme-nanotube conjugate.
Carbon nanotube Immobilization Carbon-Carbon bond hydrolase Interaction mechanism Molecular dynamics Tunnel
Hao Zhou Yuanyuan Qu
State Key Laboratory of Industrial Ecology and Environmental Engineering (MOE),School of Environmental Science and Technology,Dalian University of Technology,Dalian 116024,China
国内会议
第十一届全国博士生学术年会专题——节能环保与污染防治技术分会场论坛
成都
英文
558-566
2013-10-01（万方平台首次上网日期，不代表论文的发表时间）