Thermobifida fusca海藻糖合成酶的定点突变及其动力学性质研究  

Study on site-directed mutagenesis and kinetics of trehalose synthase from Thermobifida fusca

作　　者：王青艳[1] 陈发忠 黄福宝 韦传东 韦宇拓[1] 黄日波[1] 

机构地区：[1]广西大学生命科学与技术学院,广西南宁530005 [2]南宁中诺生物工程有限责任公司,广西南宁530003

出　　处：《广西农业生物科学》2007年第2期115-119,共5页Journal of Guangxi Agricultural and Biological Science

基　　金：国家973项目(2004CB719606)

摘　　要：对Thermobifida fusca海藻糖合成酶(TreS)保守区域的氨基酸残基I224、N242、Q333、E352和N415进行定点突变,结果表明:位点I224、N242、N415突变后酶的活力与野生型TreS相近,E352位点突变后酶的比活力提高为野生型TreS的1.25倍。突变酶的最适温度、pH、Km和Kcat没有明显变化;突变Q333R则使TreS丧失了酶活力。Five amino acid residues, I224, N242, Q333, E352 and N415, within the conserved region of TreS from Thermobifida fusca were subjected to site-directed mutagenesis,respectively. The results indicated that the TreS activities of the mutants derived from positions I224, N242 and N415 were similar to that of the wild type. The specific activity of the mutant E352R was 1.25-fold of the TreS of the wild type. The optimum pH and temperature for activity, Km and Kcat of TreS of these mutants did not significantly altered in comparison with those of TreS of the wild type . However, the mutant Q333R showed no TreS activity.

关 键 词：Thermobifida fusca 海藻糖合成酶 定点突变 

分 类 号：Q78[生物学—分子生物学]