Sequence analysis of a new norovirus(NV) isolated from Lanzou city of China was performed based on partial sequence of RNA dependent RNA polymerase(RdRp) and complete capsid protein(VP1) gene.The isolated strain CHN02/LZ35666 shared high sequence homology with GII-4 NVs.Nucleotide homologies of RdRp region and encoded capsid protein region were 90.4%-98.6% and 89.8%-95.7%,respectively,while amino acid homology of capsid protein region was 94.4%-97.4%.The analysis of GDD motif in RdRp region indicated this GDD motif of Lanzhou strain differed from those of the GII-4 predominant epidemic strains.Lanzhou strain formed an independent branch in GII-4 cluster in the phylogenetic tree based on nucleotide sequence of RdRp region and amino acid sequence of capsid protein.Sequence alignment revealed a mutation at the fourth key site of the receptor-binding interface in the strains isolated after 2002 compared with those of previous strains suggesting a possible change of binding pattern to HBGAs receptors.
为阐明GII.12型诺如病毒与组织血型抗原(Histo-blood group antigens,HBGAs)受体结合模式,本研究首先合成GII.12型诺如病毒毒株Pune株(GenBank登录号:EU921353)P区基因序列,并在原核系统中表达P蛋白,利用快速液相色谱分析鉴定P粒子的形成,将P粒子免疫小鼠,应用HBGAs表型明确的唾液样本分析P粒子的HBGAs结合模式。通过唾液结合分析,GII.12型诺如病毒Pune株与B型、AB型唾液结合较高,与A型、O型分泌型及O型非分泌型唾液结合较低,表明GII.12型诺如病毒与B抗原亲和性更高,这与先前GII.12型诺如病毒晶体结构的研究一致。这些研究提示,B型、AB型个体相对于其他血型个体,可能对GII.12型诺如病毒更具易感性。GII.12型诺如病毒与B抗原有更高的亲和性,为GII.12型诺如病毒的预防和控制提供了科学基础。
