GII.8和GII.9型诺如病毒P蛋白糖结合特征研究

Glycan binding specificity of P protein in GII.8 and GII.9 noroviruses

目的了解GII.8和GII.9型诺如病毒P蛋白的糖结合特征。方法利用大肠杆菌系统获得GII.8和GII.9诺如病毒P颗粒蛋白,通过寡糖和唾液结合实验,研究P颗粒蛋白与组织血型抗原等糖的相互作用,再采用序列比对和结构比较,分析GII.8和GII.9糖结合位点的序列和结构特征。结果GII.8 P蛋白与所检测的寡糖无明显结合,与部分人A/B/O型别唾液样本有结合。GII.9 P蛋白结合H双糖,与人A/B/O型别唾液有很好结合。序列和结构分析均显示GII.8 P蛋白具有与GIII.9相似的潜在糖受体结合位点,其位点与流行株GII.4等型别的糖受体区区相近。结论非流行株GII.8和GII.9 P蛋白与不同组织血型抗原的结合能力不同,提示可能会造成流行的差异,需要对非流行株开展持续的分子监测。

Objective To investigate the glycan binding specificity of the P protein in GII.8 and GII.9 noroviruses.Methods The P particle protein of GII.8 and GII.9 noroviruses was expressed by the Escherichia coli system.The oligosaccharide binding assay and saliva binding assay were carried out to explore the interactions between P particles and the histo-blood group antigens(HBGAs).Sequence alignment and structural superimposition were used to analyze the characteristics of the sequence and structure of the glycan binding sites.Results The P protein of GII.8 showed no obvious binding to the tested glycans while it bound to some saliva samples of A/B/O types.The P protein of GII.9 recognized H disaccharide and interacted with most of the saliva samples.The P protein of GII.8 possessed the similar potential glycan binding site as that of GII.9 according to the sequence and structural analysis.The site was close to that of prevalent GII.4 strains.Conclusions The non-dominant strains,GII.8 and GII.9 strains showed different glycan binding ability to different HBGAs,indicating that there may be discrepancy in prevalence.It is necessary to continually monitor the prevalence of non-dominant noroviruses.