论文部分内容阅读
目的扩增分枝杆菌噬菌体D29LysinB基因,对其编码蛋白序列进行生物信息学分析。方法提取分枝杆菌噬菌体D29基因组DNA,PCR扩增LysinB基因并对扩增产物测序;通过在线ProtParam、SOPMA、TMHMM、SWISS-MODEL等程序分析D29LysinB编码蛋白的生物学特征。结果噬菌体D29LysinB基因全长765bp,与预期大小基本一致;基因序列与Genbank上公布的MTB标准株同源性为100%。噬菌体D29LysinB蛋白共254个氨基酸,分子式为C1304H1993N349O358S7,理论等电点为5.78,平均疏水系数为-0.151,为亲水性蛋白。二级结构中α-螺旋、β-折叠、β-转角和无规则卷曲分别占45.67%、10.63%、7.87%和35.83%。噬菌体D29LysinB蛋白是非跨膜或分泌蛋白。预测的B细胞抗原表位为11-28,38-46,50-55,69-75,120-127,132-139,161-171,173-177,210-213,234-237;Th细胞抗原表位为33-47,151-165,100-114,201-215,219-233,223-237,44-58,47-61,158-172,165-179,176-190,235-249;CTL细胞抗原表位为102-110,143-151,52-60,60-68,95-103,217-225,56-64,175-183,240-248,45-53,150-158,199-207。该蛋白与噬菌体Chy5LysinB蛋白进化距离较近。结论生物学信息学方法分析噬菌体D29LysinB蛋白为亲水性蛋白,含有B、Th及CTL细胞其抗原表位,为研究该蛋白在分枝杆菌中的功能奠定了基础。
Objective To amplify the Mycobacterium bacteriophage D29LysinB gene and analyze its encoded protein sequence for bioinformatics analysis. Methods Mycobacterium phage D29 genomic DNA was extracted and LysinB gene was amplified by PCR. The amplified product was sequenced. The biological characteristics of D29LysinB protein were analyzed by on-line ProtParam, SOPMA, TMHMM, SWISS-MODEL and other programs. Results The full length of phage D29LysinB gene was 765bp, which was consistent with the expected size. The sequence of the gene was 100% homologous to the MTB standard strain published on Genbank. The bacteriophage D29LysinB protein has a total of 254 amino acids, the molecular formula is C1304H1993N349O358S7, the theoretical isoelectric point is 5.78 and the average hydrophobic coefficient is -0.151, which is a hydrophilic protein. Secondary structure α-helix, β-sheet, β-turn and random curl accounted for 45.67%, 10.63%, 7.87% and 35.83% respectively. Phage D29LysinB protein is a non-transmembrane or secreted protein. The predicted B cell epitopes were 11-28, 38-46, 50-55, 69-75, 120-127, 132-139, 161-171, 173-177, 210-213, 234-237; Th cell epitopes were 33-47, 151-165, 100-114, 215-219-233,223-237,44-58,47-61,158-172,165-179,176-190,235-249; CTL epitopes are 102-110, 143-151, 52-60, 60-68, 95-103, 217-225, 56- 64-175-183, 240-248, 45-53, 150-158, 199-207. The protein and phage Chy5LysinB protein evolutionary distance closer. Conclusions Bioinformatics analysis of phage display D29LysinB protein is a hydrophilic protein that contains epitopes of B, Th and CTL cells, which laid the foundation of studying the function of this protein in Mycobacterium.