Liu Qingtao, Chen Yuqi, Yuan Minglai, Du Guocheng, Chen Jian, Kang Zhen
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China, and Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, China.
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China, and Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, China
Appl Environ Microbiol. 2017 Aug 17;83(17). doi: 10.1128/AEM.01258-17. Print 2017 Sep 1.
Urease, a nickel-containing metalloenzyme, was the first enzyme to be crystallized and has a prominent position in the history of biochemistry. In the present study, we identified a nickel urease gene cluster, , in ATCC 9945a and characterized it in Enzymatic assays demonstrate that this oxygen-stable urease is also an iron-containing acid urease. Heterologous expression assays of UreH suggest that this accessory protein is involved in the transmembrane transportation of nickel and iron ions. Moreover, this iron-containing acid urease has a potential application in the degradation of urea in rice wine. The present study not only enhances our understanding of the mechanism of activation of urease but also provides insight into the evolution of metalloenzymes. An iron-containing, oxygen-stable acid urease from ATCC 9945a with good enzymatic properties was characterized. This acid urease shows activities toward both urea and ethyl carbamate. After digestion with 6 U/ml urease, approximately 92% of the urea in rice wine was removed, suggesting that this urease has great potential in the food industry.
脲酶是一种含镍金属酶，是首个被结晶的酶，在生物化学史上占据重要地位。在本研究中，我们在ATCC 9945a中鉴定出一个镍脲酶基因簇，并对其进行了表征。酶活性测定表明，这种对氧稳定的脲酶也是一种含铁酸性脲酶。UreH的异源表达分析表明，这种辅助蛋白参与镍和铁离子的跨膜运输。此外，这种含铁酸性脲酶在米酒尿素降解方面具有潜在应用。本研究不仅增进了我们对脲酶激活机制的理解，还为金属酶的进化提供了见解。对来自ATCC 9945a的具有良好酶学性质的含铁、对氧稳定的酸性脲酶进行了表征。这种酸性脲酶对尿素和氨基甲酸乙酯均有活性。用6 U/ml脲酶消化后，米酒中约92%的尿素被去除，表明这种脲酶在食品工业中具有巨大潜力。
