Effect of introducing disulfide bridges in C-terminal structure on the thermostability of xylanase XynZF-2 from Aspergillus niger
Autor: | Shao Tianci, Chen-Yan Zhou, Jingyi Li, Mishuai Zhang, Liutengzi Cai, Bingjie Ren, He You |
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Rok vydání: | 2019 |
Předmět: |
0106 biological sciences
chemistry.chemical_classification 0303 health sciences Mutation biology Stereochemistry Chemistry Aspergillus niger Mutagenesis Mutant biology.organism_classification medicine.disease_cause 01 natural sciences Applied Microbiology and Biotechnology Microbiology Amino acid 03 medical and health sciences 010608 biotechnology Xylanase medicine Site-directed mutagenesis 030304 developmental biology Thermostability |
Zdroj: | The Journal of General and Applied Microbiology. 65:240-245 |
ISSN: | 1349-8037 0022-1260 |
Popis: | In this study, a mutant xylanase of high thermostability was obtained by site-directed mutagenesis. The homologous 3D structure of xylanase was successfully modeled and the mutation sites were predicted using bioinformatics software. Two amino acids of XynZF-2 were respectively substituted by cysteines (T205C and A52C) and a disulfide bridge was introduced into the C-terminal of XynZF-2. The mutant gene xynZFTA was cloned into pPIC9K and expressed in P. pastoris. The optimum temperature of the variant XynZFTA was improved from 45°C to 60°C, and XynZFTA retained greater than 90.0% activity (XynZF-2 retained only 50.0% activity) after treatment at 50°C for 5 min. The optimum pH of mutant xylanase was similar to XynZF-2 (pH = 5.0). The pH stability span (5.0~7.0) of the mutant xylanase was increased to 3.0~9.0. Overall, the results implied that the introduction of a disulfide bridge in the C-terminal structure improved the thermostability and pH stability of XynZF-2. |
Databáze: | OpenAIRE |
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