Expression and characterization of recombinant wheat quiescin sulfhydryl oxidase and its effect on bread quality.

Nian DU; Yuanyuan Deng; Zhencheng Wei; Yan Zhang; Xiaojun Tang; Ping LI; Pengfei Zhou; Guang Liu; Mingwei Zhang

Return

Expression and characterization of recombinant wheat quiescin sulfhydryl oxidase and its effect on bread quality.

Author: Nian DU ¹ ; Yuanyuan DENG ² ; Zhencheng WEI ² ; Yan ZHANG ² ; Xiaojun TANG ² ; Ping LI ² ; Pengfei ZHOU ² ; Guang LIU ² ; Mingwei ZHANG ²
Author Information

1. College of Life Science, Yangtze University, Jingzhou 434020, Hubei, China.
2. Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Sericultural and Agri-Food Research Institute Guangdong Academy of Agricultural Sciences, Guangzhou 510610, Guangdong, China.
Publication Type:Journal Article
Keywords: bread quality; enzymatic characteristics; prokaryotic expression; wheat quiescin sulfhydryl oxidase
MeSH: Bread; Escherichia coli/genetics*; Hydrogen Peroxide; Oxidoreductases; Triticum
From: Chinese Journal of Biotechnology 2021;37(2):593-603
CountryChina
Language:Chinese
Abstract: Wheat quiescin sulfhydryl oxidase was expressed in Escherichia coli for developing a new biological flour improver. The synthesized wqsox gene was constructed into the vector pMAL-c5x and expressed in E. coli, then the expression conditions of recombinant protein was optimized. The MBP fusion label in recombinant protein was removed by protease digestion after affinity purification. Moreover, enzymatic properties of the purified wQSOX and its effect on bread quality were investigated. The synthesized wqsox gene contained 1 359 bp and encoded 453 amino acids with a deduced molecular weight of 51 kDa. The constructed recombinant vector pMAL-c5x-wqsox could successfully express soluble recombinant protein MBP-wQSOX in E. coli Rosetta gamiB(DE3), and the optimal induced expression conditions for recombinant protein were 25 °C, 0.3 mmol/L IPTG and 6 h. MBP fusion tag was cut out by factor Xa protease and wQSOX was prepared after affinity purification. wQSOX could catalyze the oxidation of DTT, GSH and Cys, accompanying the production of H2O2, and exhibited the highest substrate specificity for DTT. Furthermore, enzymatic properties results demonstrated that the optimal temperature and pH for wQSOX catalyzing oxidation of DTT was 50 °C and 10.0, respectively, and wQSOX presented a good stability under high temperature and alkaline environment. The addition of wQSOX with 1.1 U/g flour significantly (P<0.05) increased 26.4% specific volume of the bread, and reduced 20.5% hardness and 24.8% chewiness of bread crumb compared to the control, indicating a remarkable ability to improve the quality of bread.