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.
出处
《广西农业生物科学》
CAS
CSCD
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)
