讲座题目：Functionalization of enzyme by fusion protein technique (资源与环境系列学术报告)
主讲人: Dr. Kazunori Nakashima, Hokkaido University, Japan
主持人：Dr. Varenyam Achal
开始时间：2016-09-20 13:00:00
讲座地址：生科辅楼119会议室
主办单位：生态与环境科学学院 科技处
报告人简介：
Dr. Kazunori Nakashima received his PhD in chemical engineering from Kyushu University in 2007. After his postdoc at the same university, Dr. Nakashima worked as Assistant Professor at Kobe University and Tohoku University between 2009 and 2013. Since 2014, he is working as Associate Professor at Hokkaido University, Japan. His research area of interests includes biomineralization, protein engineering and biomass pretreatment-conversion in biorefinery process. He has published more than 40 research articles in his expertise.
报告摘要:
Fusion protein technique is one of the powerful tools to enhance the function of original protein/enzyme. Here we show two examples of functionalization of enzyme by fusion technique.
Lignocellulosic biomass, composed of cellulose, hemicellulose, and lignin, is abundant and renewable resource in bio-refinery process. Cellulose in biomass is degraded into fermentable sugars such as glucose by the action of cellulase. One of the most serious obstacles in the utilization of cellulose lies on the low digestibility by cellulase, mainly because of highly crystalline structure of cellulose. The pretreatment of biomass to obtain high digestibility often involves chemicals such as acids and alkaline, which should be removed before enzymatic hydrolysis, and also requires high-energy consumption at high temperature and pressure. Expansin is a plant protein, which is capable of loosening the packaging of the plant cell wall and disrupting cellulose crystal, and it was also found in bacteria such as Bacillus subtilis. We have constructed a novel fusion enzyme composed of bacterial expansin and endoglucanase (cellulase) for efficient degradation of cellulose.
Silicatein is an enzyme, which catalyzes silica polycondensation in marine sponge. The enzyme can produce silica from siliceous substrate such as tetraethoxysilane under mild condition. Silicatein could be used for the solidification of materials and the fabrication of bio-hybrid materials. After silicatein is expressed in sponge, propeptide of the enzyme is removed by autolytic cleavage to form mature silicatein, which is known to self-assemble to form filamentous aggregation. The aggregation property would be a barrier in the application of silicatein. We have prepared fusion protein composed of silicatein and small soluble protein, ProS2, to make silicatein soluble in a solution.