Guan Lihong, Chen Liping, Chen Yongsen, Zhang Nu, Han Yawei
College of Food and Bioengineering, Zhengzhou University of Light Industry, Number 5, Dongfeng Road, Zhengzhou, 450002, China.
College of Life Science and Technology, Xinxiang Medical University, Xinxiang, China.
Protein J. 2017 Aug;36(4):352-360. doi: 10.1007/s10930-017-9725-y.
The fructosyltransferase gene was isolated and cloned from Aspergillus oryzae. The gene was 1368 bp, which encoded a protein of 455 amino acids. To analyze the activity of the expressed fructosyltransferase, the pET32a-fructosyltransferase recombined plasmid was transformed into Escherichia coli BL21. The fructosyltransferase gene was successfully expressed by Isopropyl-β-d-thiogalactoside (IPTG) induction. The molecular weight of the expression protein was about 45 kDa. The optimal conditions of protein expression were 25 °C, 0.1 mM IPTG, and 8 h of inducing time. The optimal concentration of urea dealing with inclusion body was 2.5 M. The expressed protein exhibited a strong fructosyl transfer activity. These results showed that the expressed fructosyltransferas owned transferase activity, and could catalyze the synthesis of sucrose-6-acetate.
从米曲霉中分离并克隆了果糖基转移酶基因。该基因长度为1368 bp，编码一个由455个氨基酸组成的蛋白质。为了分析表达的果糖基转移酶的活性，将pET32a-果糖基转移酶重组质粒转化到大肠杆菌BL21中。通过异丙基-β-D-硫代半乳糖苷（IPTG）诱导成功表达了果糖基转移酶基因。表达蛋白的分子量约为45 kDa。蛋白质表达的最佳条件为25 °C、0.1 mM IPTG和8 h诱导时间。处理包涵体的尿素最佳浓度为2.5 M。表达的蛋白表现出很强的果糖基转移活性。这些结果表明，表达的果糖基转移酶具有转移酶活性，能够催化蔗糖-6-乙酸酯的合成。
