A fusion enzyme consisting of bacterial expansin and endoglucanase for the degradation of highly crystalline cellulose
A fusion enzyme consisting of bacterial expansin and endoglucanase for the degradation of highly crystalline cellulose
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DOI：
10.1039/c4ra05891g
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发表时间：
2014-09
期刊：
影响因子：
3.9
通讯作者：
K. Nakashima;K. Endo;N. Shibasaki-Kitakawa;T. Yonemoto
中科院分区：
文献类型：
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作者：
K. Nakashima;K. Endo;N. Shibasaki-Kitakawa;T. Yonemoto
我们制备了由枯草芽孢杆菌扩展蛋白 EXLX1 和热纤梭菌内切葡聚糖酶 CelD 组成的新型融合酶。这两个组件直接融合，或使用不同长度的柔性甘氨酸-丝氨酸肽接头（GGGGS、GS接头）进行融合：三重（GGGGS）3接头（GS3）和六重（GGGGS）6接头（GS6），产生融合酶EXLX1-CelD、EXLX1-GS3-CelD和EXLX1-GS6-CelD。检查了这些融合酶对一系列具有不同结晶度指数 (CrI) 的纤维素底物的结合能力和消化率。 CelD与EXLX1融合后，获得了与多种纤维素的高结合能力，且连接子长度对功能没有影响。在纤维素的降解中，EXLX1-GS3-CelD 在所检测的融合酶中表现出最高的降解活性，这表明两种蛋白之间的接头长度对融合酶的活性具有显着影响。发现 EXLX1-GS3-CelD 对更高结晶纤维素的作用更有效。
We have prepared novel fusion enzymes consisting of Bacillus subtilis expansin EXLX1 and Clostridium thermocellum endoglucanase CelD. These two components are directly fused, or fused using flexible glycine–serine peptide linkers (GGGGS, GS linker) with different lengths: a triplicate (GGGGS)3 linker (GS3) and a sextuple (GGGGS)6 linker (GS6), resulting in fusion enzymes EXLX1-CelD, EXLX1-GS3-CelD and EXLX1-GS6-CelD. The binding ability and digestibility of these fusion enzymes towards a series of cellulose substrates with different crystallinity index (CrI) was examined. Fused with EXLX1, CelD acquired high binding ability to various kinds of cellulose and the linkaer length had no impact on function. In the degradation of cellulose, EXLX1-GS3-CelD exhibited the highest degradation activity among the fusion enzymes examined, suggesting that linker length between the two proteins has a significant impact on the activity of the fusion enzyme. EXLX1-GS3-CelD was found to function more effectively towards higher crystalline celluloses.