Oh Hyo-Jung, Kim Hye-Jung, Oh Deok-Kun
Department of Bioscience and Biotechnology, Sejong University, Seoul, 143-747, South Korea.
Biotechnol Lett. 2006 Feb;28(3):145-9. doi: 10.1007/s10529-005-5327-4.
Among single-site mutations of L-arabinose isomerase derived from Geobacillus thermodenitrificans, two mutants were produced having the lowest and highest activities of D-tagatose production. Site-directed mutagenesis at these sites showed that the aromatic ring at amino acid 164 and the size of amino acid 475 were important for D-tagatose production. Among double-site mutations, one mutant converted D-galactose into D-tagatose with a yield of 58% whereas the wild type gave 46% D-tagatose conversion after 300 min at 65 degrees C.
在源自嗜热栖热放线菌的L-阿拉伯糖异构酶的单点突变中，产生了两个具有最低和最高D-塔格糖生产活性的突变体。在这些位点进行定点诱变表明，第164位氨基酸的芳香环和第475位氨基酸的大小对D-塔格糖的生产很重要。在双点突变中，一个突变体将D-半乳糖转化为D-塔格糖的产率为58%，而野生型在65℃下300分钟后D-塔格糖的转化率为46%。
