Kim Ho Jeong, Kim Bong Gyu, Kim Jae Ah, Park Younghee, Lee Yoon Jung, Lim Yoongho, Ahn Joong-Hoon
Bio/Molecular Informatics Center, Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Korea.
J Microbiol Biotechnol. 2007 Mar;17(3):539-42.
Glycosyltransferase family 1 (UGT) uses small chemicals including phenolics, antibiotics, and alkaloids as substrates to have an influence in biological activities. A glycosyltransferase (XcGT-2) from Xanthomonas campestris was cloned and consisted of a 1,257 bp open reading frame encoding a 45.5 kDa protein. In order to use this for the modification of phenolic compounds, XcGT-2 was expressed in Escherichia coli as a glutathione S-transferase fusion protein. With the E. coli transformant expressing XcGT-2, biotransformation of flavonoids was carried out. Flavonoids having a double bond between carbons 2 and 3, and hydroxyl groups at both C-3' and C-4', were glycosylated and the glycosylation position was determined to be at the hydroxyl group of C-3', using nuclear magnetic resonance spectroscopy. These results showed that XcGT-2 regiospecifically transferred a glucose molecule to the 3'-hydroxyl group of flavonoids containing both 3' and 4'-hydroxyl groups.
糖基转移酶家族1（UGT）利用包括酚类、抗生素和生物碱在内的小分子化学物质作为底物，对生物活性产生影响。从野油菜黄单胞菌中克隆出一种糖基转移酶（XcGT-2），其由一个1257 bp的开放阅读框组成，编码一种45.5 kDa的蛋白质。为了将其用于酚类化合物的修饰，XcGT-2在大肠杆菌中作为谷胱甘肽S-转移酶融合蛋白表达。利用表达XcGT-2的大肠杆菌转化体进行了类黄酮的生物转化。对在碳2和碳3之间具有双键且在C-3'和C-4'处均有羟基的类黄酮进行了糖基化，并使用核磁共振光谱确定糖基化位置在C-3'的羟基处。这些结果表明，XcGT-2区域特异性地将一个葡萄糖分子转移到同时含有3'和4'-羟基的类黄酮的3'-羟基上。
