关键词: 异亮氨酸双加氧酶, 异亮氨酸, 羟基异亮氨酸, 生物转化, 重组表达

Abstract: Isoleucine dioxygenase (IDO) could hydroxylyze L-isoleucine (L-Ile) to produce 4-hydroxy-L-isoleucine (4-HIL)，which increases glucose-induced insulin release and is usually used in pharmaceuticals with antidiabetic and cholesterol-reducing properties. The strain with dioxygenase activity was screened from nature via combination of reaction coloration assayed by spectrophotometer and thin-layer chromatography (TLC). The gene encoding IDO (ido) was cloned and expressed in Escherichia coli and the constructed recombinant strain exhibited the function of isoleucine hydroxylation. The reaction conditions were optimized and the yield of transformation with the recombinant whole cells was increased to more than 85% by incubating the cells overnight at 30℃. The newly identified IDO and involved recombinant whole cells would be promising to prepare 4-HIL with high efficiency.

Key words: isoleucine dioxygenase, isoleucine, hydroxyl isoleucine, biotransformation, recombinant expression