Mei Hui-Zhen, Xia Ding-Guo, Zhao Qiao-Ling, Zhang Guo-Zheng, Qiu Zhi-Yong, Qian Ping, Lu Cheng
Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, Jiangsu 212018, China.
Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, Jiangsu 212018, China.
Gene. 2016 Jan 15;576(1 Pt 1):45-51. doi: 10.1016/j.gene.2015.09.057. Epub 2015 Sep 26.
Wood-feeding insects depend heavily on the secretion of a combination of cellulases, mainly endoglucanases and other glucanases such as exoglucanases and xylanases, to achieve efficient digestion of the cellulose of cellulosic materials. In this paper, we report a novel cellulose Bh-EGaseI belonging to the glycoside hydrolase family 45(gh45-1) obtained from the beetle Batocera horsfieldi. The Bh-EGaseI gene spans 714 bp and consists of three exons coding 237 amino acid residues. The cDNA encoding Bh-EGaseI was expressed as 25 KDa in baculovirus-infected Bombyx mori larvae. The expression products of Bh-EGaseI from larval hemolymph showed a specific enzymatic activity of approximately 1030.87 IU per mg. The enzyme was active over a wide range of pH and temperatures; optimal activity was observed at 40 °C and pH 4.0. The effects of ions on Bh-EGaseI activity were also studied, and results indicated that activity decreased to different extents upon addition of ions. Investigations on Bh-EGaseI facilitate their potential application in the production of bioenergy and biomaterials from cellulosic biomass in the future.
以木材为食的昆虫严重依赖于多种纤维素酶（主要是内切葡聚糖酶和其他葡聚糖酶，如外切葡聚糖酶和木聚糖酶）的分泌，以实现对纤维素材料中纤维素的有效消化。在本文中，我们报道了一种从黄斑星天牛（Batocera horsfieldi）中获得的属于糖苷水解酶家族45（gh45 - 1）的新型纤维素酶Bh - EGaseI。Bh - EGaseI基因跨度为714 bp，由三个外显子组成，编码237个氨基酸残基。编码Bh - EGaseI的cDNA在杆状病毒感染的家蚕幼虫中表达为25 kDa。来自幼虫血淋巴的Bh - EGaseI表达产物显示出约每毫克1030.87 IU的比酶活性。该酶在较宽的pH和温度范围内具有活性；在40°C和pH 4.0时观察到最佳活性。还研究了离子对Bh - EGaseI活性的影响，结果表明添加离子后活性会不同程度地降低。对Bh - EGaseI的研究有助于其未来在从纤维素生物质生产生物能源和生物材料方面的潜在应用。
