Selective Detoxification of Phenols by Pichia pastoris and Arabidopsis thaliana Heterologously Expressing the PtUGT72B1 from Populus trichocarpa
Selective Detoxification of Phenols by Pichia pastoris and Arabidopsis thaliana Heterologously Expressing the PtUGT72B1 from Populus trichocarpa
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异源表达毛果杨 PtUGT72B1 的毕赤酵母和拟南芥对酚类的选择性解毒
DOI：
10.1371/journal.pone.0066878
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发表时间：
2013-06-26
期刊：
影响因子：
3.7
通讯作者：
Yao, Quan-Hong
中科院分区：
文献类型：
--
作者：
Xu, Zhi-Sheng;Lin, Ya-Qiu;Yao, Quan-Hong
苯酚存在于环境中，由于其在许多行业中的广泛应用，通常与人类和动物接触。在以前的研究中，我们报道了从胡杨尿苷二磷酸葡萄糖依赖的葡萄糖基转移酶PtUGT 72 B1具有高活性的解毒三氯苯酚通过共轭葡萄糖。在这项研究中，进行了更多的实验，以确定PtUGT 72 B1对酚类化合物的底物特异性。在测试的七种酚中，三种被PtUGT 72 B1葡糖基化，包括苯酚、对苯二酚和邻苯二酚。表达PtUGT 72 B1酶的转基因拟南芥植物对氢醌和邻苯二酚表现出更高的抗性，但对苯酚比野生型植物更敏感。表达PtUGT 72 B1的转基因毕赤酵母对所有三种酚的抗性增强。与野生型拟南芥相比，转基因拟南芥对3种酚类物质的去除效率更高，并向培养基中输出更多的酚类糖苷--苯基β-D-吡喃葡萄糖苷。转基因拟南芥植株的蛋白质提取物对苯酚、对苯二酚和邻苯二酚的结合活性增强。PtUGT 72 B1在毕赤酵母中的表达量明显高于在拟南芥中的表达量。还进行了PtUGT 72 B1的动力学分析。
Phenols are present in the environment and commonly in contact with humans and animals because of their wide applications in many industries. In a previous study, we reported that uridine diphosphate-glucose-dependent glucosyltransferase PtUGT72B1 from Populus trichocarpa has high activity in detoxifying trichlorophenol by conjugating glucose. In this study, more experiments were performed to determine the substrate specificity of PtUGT72B1 towards phenolic compounds. Among seven phenols tested, three were glucosylated by PtUGT72B1 including phenol, hydroquinone, and catechol. Transgenic Arabidopsis plants expressing the enzyme PtUGT72B1 showed higher resistance to hydroquinone and catechol but more sensitivity to phenol than wild type plants. Transgenic Pichia pastoris expressing PtUGT72B1 showed enhanced resistance to all three phenols. Compared with wild type Arabidopsis plants, transgenic Arabidopsis plants showed higher removal efficiencies and exported more glucosides of phenol, phenyl β-D-glucopyranoside, to the medium after cultured with the three phenols. Protein extracts from transgenic Arabidopsis plants showed enhanced conjugating activity towards phenol, hydroquinone and catechol. PtUGT72B1 showed much higher expression level in Pichia pastoris than in Arabidopsis plants. Kinetic analysis of the PtUGT72B1 was also performed.