日本斑点热立克次体安徽120株ompB基因及其编码蛋白的生物信息学和B细胞抗原表位分析  

Analysis of bioinformatics and B cell epitope of ompB gene and its encoded protein from R.Japonica strain Anhui 120

作　　者：刘伯玉[1] 罗婉蓉 陈振[1] 余冬阳 高越 朱禹 洪颖 杨莉 柳燕[1] Liu Boyu;Luo Wanrong;Chen Zhen(Dept of Microbiology,AnhuC Medical University,Befet 230032)

机构地区：[1]安徽医科大学微生物学教研室,合肥230032 [2]马鞍山疾病预防控制中心,马鞍山243000

出　　处：《安徽医科大学学报》2020年第6期819-824,共6页Acta Universitatis Medicinalis Anhui

基　　金：“十三五”国家科技重大专项(编号:2018ZX10711001);国家自然科学基金(编号:81571963,81772203)。

摘　　要：目的对从我国临床患者血液中新发现和分离出的日本斑点热立克次体安徽120株ompB基因及其编码蛋白进行系统的结构与功能预测,为深入了解其在立克次体致病机制中的作用、研发斑点热临床诊断试剂和疫苗提供理论基础。方法基于日本斑点热立克次体安徽120株ompB基因及其编码的氨基酸序列,应用生物信息学方法预测其信号肽、跨膜区、疏水性等性质和可能的B细胞抗原表位。结果日本斑点热立克次体安徽120株ompB基因在3 297~3 311处存在连续15个碱基的缺失,除此之外,该分离株还有4个碱基突变。该基因编码的氨基酸数目为1 651个,蛋白质分子量为167.69 ku,共由20种氨基酸组成,其中含量较多的氨基酸是Gly;理论等电点pI为5.15,消光系数为58 805或58 680,蛋白不稳定指数为7.15,脂肪指数为88.86,总平均亲水性(GRAVY)为0.06,为疏水性蛋白;Signal peptide (Sec/SPI) Likelihood为0.567 7,有信号肽序列;存在一个Pfam区域和自转运体区,分别与细菌黏附宿主和蛋白质转运有关;蛋白二级结构中以无规卷曲为主,其次为β-折叠和α-螺旋,分别占到53.73%、30.83%和15.45%。同源模建蛋白的三级结构中,第1 308~1 651氨基酸部分在蛋白表面形成桶状结构,可能具有丝氨酸蛋白酶的作用;蛋白分子内抗原表位较丰富,共有159个可能的抗原表位,预测分数最高(0.94)的为1 269~1 284位序列。结论成功分析和预测了日本斑点热立克次体安徽120株ompB基因及其编码蛋白的组成、蛋白质的二级结构、三级结构和B细胞抗原表位,为研究日本斑点热立克次体的致病机制、临床诊断试剂和亚单位疫苗的研发提供了理论支持。Objective To systematically predict the structure and function of the ompB gene and its encoded protein from the newly discovered R.Japonica Strain Anhui 120 isolated from the blood of clinical patients in China,so as to provide a theoretical basis for the role in pathogenic mechanisms of rickettsia,the development of diagnostic reagents and vaccines of clinical spotted fever.Methods Based on the ompB gene and its encoded amino acid sequence of R.Japonica strain Anhui 120,bioinformatics method was used to predict the signal peptide,transmembrane region,hydrophobicity and possible B cell epitopes.Results There were 15 deletions of consecutive bases of the 3297~3311 in the ompB gene of R.Japonica strain Anhui 120.In addition,the isolate also had 4 base mutations.The number of amino acids encoded by the gene was 1651,the molecular weight of the protein was 167.69 ku,and there were 20 kinds of amino acids.The amino acid with more content was Gly.The theoretical isoelectric point pI was 5.15,the extinction coefficient was 58805 or 58680,the unstable index was 7.15,the fat index was 88.86,the total average hydrophilicity(GRAVY)was 0.06 and it was hydrophobic protein,the Signal peptide(Sec/SPI)Likelihood was 0.5677 with signal peptide sequence.There was a Pfam region and autotransporter region,which was associated with bacterial adhesion to host and protein transport respectively.The main secondary structure of the protein was random coils,followed byβ-sheet andα-helix,accounting for 53.73%,30.83%and 15.45%,respectively.In the tertiary structure of homologous model protein,the amino acid of 1308~1651 formed a barrel-like structure on the surface of the protein,which might have the action of serine protease.The antigenic epitope in the protein molecule was rich,and there were 159 possible epitopes.The highest predicted score(0.94)was the sequence of 1269~1284.Conclusion The composition of the ompB gene and its encoded protein,the secondary structure,tertiary structure and B cell epitope of R.Japonica strain Anhui 120 w

关 键 词：日本斑点热立克次体安徽120株 ompB B细胞抗原表位 生物信息学 

分 类 号：R376.3[医药卫生—病原生物学]