%0 Journal Article %T 脱毛碱性蛋白酶(DHAP)的饱和突变<br>Saturation mutagenesis of the dehairing alkaline protease %A 黄 %A 蓉 %A 冯 %A 红 %J 四川大学学报 (自然科学版) %D 2015 %X 本实验在同源建模和氨基酸序列比对的基础上, 选取脱毛碱性蛋白酶(DHAP)8个氨基酸位点进行饱和突变. 通过牛奶平板和96孔板发酵筛选, 获得了4个催化特性改良的突变体, 测序鉴定为D248F, D248S, M233L和W214K. 利用酪蛋白和合成肽(AAPL ??p??N)作为底物, 对这些突变体进行了评价, 结果表明D248F、D248S、W214K在常温(28℃)下的酪蛋白水解活性提高; M233L在常温、高温(50℃)的酶活以及热稳定性都有增加. 同时, M233L和W214K在25℃和50℃水解AAPL ??p??N的酶活也分别得到了不同程度的提高.<br>From ??Bacillus pumilus?? BA06 an dehairing akaline protease(DHAP) has a good dehairing function and can be applied to relevant industries. On the basis of the homolog modeling and the multiple amino acids alignments, 8 amino acid residues of DHAP were selected for saturation mutagenesis. After screening on the skim milk plates and fermentation in the 96 well plates, 4 mutants were obtained and identified as D248F, D248S, M233L and W214K by DNA sequencing. The catalytic activities of D248F, D248S and W214K towards casein were improved at 28℃. And the caseinolytic activities of M233L were also improved at 50℃, 28℃, and after treatment at 65℃ for 10 minutes. The hydrolytic activities of M233L and W214K towards AAPL ??p??N were enhanced at 50℃ and 25℃ %K 脱毛碱性蛋白酶 短小芽胞杆菌 饱和突变 冷适应 热稳定性 酶活性< %K br> %K Alkaline protease ??Bacillus pumilus?? Site directed mutagenesis Cold adaptation Thermostability Protease activity %U http://science.ijournals.cn/jsunature_cn/ch/reader/view_abstract.aspx?file_no=20155040&flag=1