人巨细胞病毒UL149蛋白结合多肽的氨基酸序列分析

目的 初步确定与UL149蛋白具有较强结合能力的多肽,并对这些多肽氨基酸序列的特点进行分析.方法 应用随机多肽文库分别筛选与UL1493种不同基因型克隆表达的UL149蛋白结合的克隆,并测序,对相应的多肽氨基酸序列进行同源性比较,并与蛋白数据库中已知的蛋白序列进行比较.结果 与3种不同基因型的UL149蛋白结合的多肽序列之间具有较高的同源性,氨基酸序列中存在较为集中的区域,即W/A/F/V-D/E-D/E-G-W/F/I/L.与已知人类蛋白数据库进行比较,发现与人免疫球蛋白重链可变区关系密切,并与SH3、WD结构域、丝氨酸/苏氨酸蛋白激酶、补体因子H、锌脂蛋白、MHC Ⅰ类分子、真核细胞转录起始因子、核因子NF等存在结合关系.结论 人巨细胞病毒UL149蛋白可能通过多条途径来干扰机体对人巨细胞病毒的免疫应答反应.

Amino acid sequences analysis of human cytomegalovirus UL149 proteins binding peptides

Objective To identify the peptide that have strong ability binding to HCMV-UL149 encoded protein,and to analyze the characteristics of the amino acid sequence of UL149-binding peptides.Methods Expressed UL149 proteins of three genotypes were used to screen the binding peptide in the random peptide display library,then the encoding sequence of binding peptides in the selected clones were sequenced.The amino acid sequences of the binding peptides were analyzed for their homology,and were com pared with those of the known protein in protein banks.Results The homologous amino acid sequence W/A/F/V-D/E-D/E-G-W/F/I/L were found within the binding peptides selected by proteins of all the three UL149 genotypes proteins,and no difference between three groups was found.The alignment with amino acid sequences of the known proteins in protein banks showed that the binding peptides of UL149 putative protein have homologous amino acid sequences with immunoglobulin heavy chain variable region(IgHV),the serine/threonine protein kinases,compliment factor H,zinc finger protein,MHC Ⅰ molecule,eukaryotic translation initiation factor,nuclear factor and so on.Conclusion The UL149 encoding proteins have binding ability to proteins mentioned above,and might interfere with the immunity responds to HCMV infection through multiple mechanisms.