Analysis of immobilized L-glutamate oxidase fused with cellulose binding domain on microcrystalline cellulose.

Hui Song; Wenyu Zhang; Pengju Wang; Huanbo Tan; Wencheng SU; Shuxin Zhao; Peijian Zou

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Analysis of immobilized L-glutamate oxidase fused with cellulose binding domain on microcrystalline cellulose.

Author: Hui SONG ¹ ; Wenyu ZHANG ² ; Pengju WANG ² ; Huanbo TAN ² ; Wencheng SU ² ; Shuxin ZHAO ¹ ; Peijian ZOU ²
Author Information

1. College of Bioengineering, Tianjin University of Science and Technology, Tianjin 300457, China.
2. National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Publication Type:Journal Article
Keywords: L-glutamate oxidase; cellulose binding domain; immobilized
From: Chinese Journal of Biotechnology 2016;32(10):1348-1361
CountryChina
Language:Chinese
Abstract: Immobilization of enzymes is important and widely applied in biocatalysis. Streptomyces platensis gene gox, encoding an extracellular L-glutamate oxidase (Gox), was fused to cellulose binding domain (CBDcex) from Cellulomonas fimi and the recombinant protein Gox-CBD was expressed in Escherichia coli. The fusion protein (Gox-CBD) was immobilized onto microcrystalline cellulose. The preparation conditions, binding capacity, properties and stability of the immobilized enzyme were studied. Under the condition of 4 ℃, for 1 hour, the fusion protein Gox-CBD was able to bind microcrystalline cellulose at a ratio of 9.0 mg of protein per gram of microcrystalline cellulose. Enzymatic properties of free and immobilized L-glutamic oxidase (Gox-CBD) were compared. The specific activity of the immobilized enzyme decreased, but its thermal stability increased a lot compared with that of the free Gox-CBD. After incubation at 60 ℃ for 30 min, 70% of the total activity remained whereas the free recombinant Gox completely lost its activity. The immobilized protein was tightly bound to microcrystalline cellulose at pH below 10 or more than 5 mmol/L NaCl. The fusion protein of Gox-CBD can be specifically immobilized on the microcrystalline cellulose on a single step. Therefore, our findings can provide a novel strategy for protein purification and enzyme immobilization.