中国幽门螺杆菌强细胞毒株和弱细胞毒株vacA基因全长序列特征与VacA活性的关系  

Relationship between full-length sequence characteristics of the vacA gene from high-cytotoxic and low-cytotoxic Helicobacter pylori in China and VacA activities

作　　者：杨泽民[1] 

机构地区：[1]广东药学院基础学院,广东省广州市510006

出　　处：《世界华人消化杂志》2011年第33期3446-3451,共6页World Chinese Journal of Digestology

基　　金：国家自然科学基金资助项目;No.81102703

摘　　要：目的:探讨中国幽门螺杆菌(Helicobacter pylori,H.pylori)强细胞毒株和弱细胞毒株vacA基因序列差异对其VacA活性的影响.方法:从GenBank数据库下载4个强细胞毒株和4个弱细胞毒株vacA基因全长DNA和氨基酸序列,利用DNAMAN、lasergene 7.0、MEGA 5.03个生物信息学软件对其进行分析.结果:(1)中国H.pylori强细胞毒株、弱细胞毒株和西方强细胞毒株60190株3者之间在vacA基因序列上都存在明显的差异,这些差异主要集中在vacA基因p55结构域,表现为疏水性氨基酸与极性氨基酸之间的转换;(2)弱细胞毒株还存在多个插入变异位点;(3)强细胞毒株和弱细胞毒株,中国和西方分离株在系统发育树中分别聚类为不同的谱系.结论:vacA基因序列差异和插入突变可能是导致中国不同H.pylori VacA活性差异的重要原因.AIM: To evaluate the effect of vacA gene sequence variation on VacA activity by analyzing the full- length sequence of the vacA gene of highand low-cytotoxic Helicobacter pylori (H. pylori) strains isolated from China. METHODS: The full-length sequences of the vacA gene of four highand four low-cytotoxic H. pylori strains were retrieved from GenBank database and analyzed using three bioinformatic programs (DNAMAN, Lasergene 7.0 and MEGA 5.0). RESULTS: There existed significant sequence variations in the vacA gene among highand low-cytotoxic H. pylori strains isolated fromChina and a high-cytotoxic H. pylori 60190 strain isolated from west country. These variations were mainly concentrated on the p55 domain of the vacA gene, resulting in transitions between hydrophobic and polar amino acids. Several insertion variations were detected in low-cytotoxic H. pylori strains compared to the H. pylori 60190 strain. Highand low-cytotoxic strains as well as strains isolated from China and west countrywere clustered as different H. pylori lineages. CONCLUSION: Sequence and insert variation in the vacA gene might be an important reason resulting in VacA activity difference among H. pylori strains.

关 键 词：幽门螺杆菌 VACA基因 DNA序列 氨基酸序列 系统发育树 

分 类 号：R378.99[医药卫生—病原生物学]