Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701, South Korea.
Biotechnol Lett. 2010 Dec;32(12):1947-53. doi: 10.1007/s10529-010-0385-7. Epub 2010 Sep 1.
A putative L-rhamnose isomerase (RhaA) from Thermotoga maritima was purified with a specific activity of 55 U/mg by His-Trap affinity chromatography. The native enzyme was estimated as a 46 kDa tetramer by gel filtration chromatography. The half-lives of the enzyme at 75, 80, 85, 90 and 95°C were 773, 347, 187, 118, and 65 h, respectively, indicating that it is the most thermostable of all RhaAs. Under the optimum conditions of pH 8.0, 85°C, and 1 mM Mn(2+), RhaA with 100 U enzyme/ml converted 500 L-xylulose/l to 225 g/l L-lyxose after 3 h, and converted 500 L-fructose/l to 175 g/l L-mannose after 5 h.
来自海洋栖热菌（Thermotoga maritima）的假定 L-鼠李糖异构酶（RhaA）通过 His-Trap 亲和层析法进行纯化，比活为 55 U/mg。凝胶过滤层析法估计天然酶为 46 kDa 四聚体。该酶在 75、80、85、90 和 95°C 下的半衰期分别为 773、347、187、118 和 65 h，表明其是所有 RhaA 中最耐热的。在最适条件下（pH 8.0、85°C 和 1 mM Mn(2+)），每毫升含 100 U 酶的 RhaA 将 500 L-木酮糖/L 转化为 225 g/L L-阿拉伯糖，用时 3 小时，将 500 L-果糖/L 转化为 175 g/L L-甘露糖，用时 5 小时。
