湖北肠道病毒EV71型流行株VP1基因以及蛋白结构特征分析

Genetic,structural and functional characteristics of VP1gene of enterovirus 71strains in Hubei Province

目的全面研究和了解2011年湖北省肠道病毒71型的VP1基因及蛋白结构特征，分析EV71型病毒在湖北省的基因型别，探讨该型病毒在全省的地理分布特征。方法对2011年湖北省8个区市的20株EV71流行株进行VP1区全长基因序列测定，并对核苷酸序列进行同源性比较及系统进化分析，并对VP1蛋白序列的亲水性、柔韧性等二级和三级结构进行分析。结果2011年湖北省EV71型流行株的基因亚型为C4a亚型，其VP1区核苷酸和蛋白氨基酸序列同源性较高，分别为96．5％～98．7％和98．3％～100％。VP1蛋白特征分析发现该区主要免疫表位均没有发生变异且存在较多亲水性区域。二级结构以无规则卷曲为主，其次为8片层。蛋白质同源建模未发现不同毒株间VP1蛋白三级结构差别。结论2011年湖北省Ev71型流行株与我国其它地区的毒株有较高同源性，且存在一定的地理区域聚集性特征和遗传多样性特点。同时综合多种方法预测EV71VP1的二级结构和三级结构，为进一步研究开发相关药品和防治EV71感染提供理论基础。

To investigate the genetic background of enterovirus type 71 （EV71） in H ubei Province, the genetic charac- teristics of VP1 genes and the distribution of EV71 strains were analyzed in this study. The complete VP1 sequences of 20 EV71 strains from clinical samples were amplified by RT-PCR and sequenced for the homological and phylogenetic analysis as well as the analysis of the hydrophilicity, flexibility, the secondary and tertiary structure of EV71 viral protein. The results showed that the EV71 strains in Huhei belonged to C4a cluster of the C4 subgenotype. The nucleotide and amino acid identity of VP1 region were 96.5 %-98.7% and 98.3 %-100 %, respectively. More hydrophilicity regions existed in VP1 proteins. The main immune epitope had no change. No difference on hydrophily, flexibility, surface region or antigen region was found. The random coils were the main structural type followed by 13-sheet. The homology modeling of tertiary structure showed that no difference in VP1 protein was found among different EV71 strains. The EV71 strains in Hubei showed a high identity to the other strains in China and the analysis of secondary and tertiary structure provided the scientific basis to the study of diagnosis, treatmentand epidemic processing for HFMD outbreak.