Chen Qiang, You Delin, Hu Meihao, Gu Xiaocheng, Luo Ming, Lu Shanyun
Laboratory of Structural Biology, College of Life Sciences, Peking University, Beijing 100871, PR China.
Protein Expr Purif. 2003 Dec;32(2):239-45. doi: 10.1016/j.pep.2003.08.001.
Hypoxanthine-guanine phosphoribosyltransferase (HGPRT, EC 2.4.2.8) from a newly characterized thermophile Thermoanaerobacter tengcongensis was expressed in Escherichia coli and purified. Analytical gel filtration suggested that the enzyme exist as a homotetramer in solution. The optimal pH for the forward reaction was found to be 8.0 and the optimal temperature 70 degrees C. The steady-state kinetic characteristics suggest that hypoxanthine is the most effective substrate. This enzyme showed a half-life of 75min at 50 degrees C and no apparent loss of activity after 3 months at 4 degrees C.
来自新鉴定的嗜热栖热放线菌的次黄嘌呤-鸟嘌呤磷酸核糖转移酶（HGPRT，EC 2.4.2.8）在大肠杆菌中表达并纯化。分析凝胶过滤表明该酶在溶液中以同四聚体形式存在。发现正向反应的最佳pH值为8.0，最佳温度为70摄氏度。稳态动力学特征表明次黄嘌呤是最有效的底物。该酶在50摄氏度下的半衰期为75分钟，在4摄氏度下放置3个月后活性无明显损失。
