Design and fabrication of nanostructured enzyme catalysts

Professor Zheng Liu

时间：May. 18, 2017, Thurs. 2:00-3:00 pm

地点:图书馆中心会议室   

Abstract：

Enzymatic reactions occur in mild natural environments with high chemo-, regio-, and stereo-selectivity, making enzymes ideal catalysts for industrial synthesis of chemicals, particularly those with complex molecular structures. However, native enzymes can easily lose their catalytic capabilities under harsh conditions such as high temperature and exposure to organic solvents typical in industrial operations. Recent advances in bio-catalysis indicate that enzyme stability and activity can be drastically improved under small confinement with tailor-made pore size and surface properties. A number of molecular self-assembly techniques have been developed for the controlled synthesis of the nanostructures with either single or multiple enzymes, promising their applications to industrial chemical processes. This presentation will summarize our recent efforts in incorporating nanostructured materials with enzymes for enhanced stability under adverse conditions such as high temperature and the exposure to organic solvents. In addition to an enhanced stability, the nanostructured enzyme catalyst mayappear a higher activity and selectivity over their native counterparts in free form. Recycle and operation of these nanostructured enzyme catalysts can be facilitated by suitable attachment of stimuli responsiveness of nanostructured materials. The molecular and process mechanisms underpinned the enhanced stability and activity will be discussed using enzyme nanogel, enzyme-polymer conjugate and nanostructured enzyme cascade as examples.

Biography:

Prof. Zheng Liu obtained his bachelor"s, master"s and doctoral degrees in chemical engineering from Tsinghua University in 1987, 1989 and 1993, respectively. He worked as a UNESCO Research Fellow at Tokyo Institute of Technology, Japan, during 1993 to 1994 and served as a Professor at department of chemical engineering, Tsinghua University since 1998. His current research focuses on chemical and biomolecular engineering with special interests in protein conformational transition, nanostructured enzyme catalysts, and soil bioremediation techniques, and has resulted in 200 peer-reviewed journal papers. He has supervised50 graduate students, one of which received the National Best PhD Dissertation Award in 2008. Prof. Liu was awarded as Chang Jiang Scholars Professor of biochemical engineering, Ministry of Education, in 2012.