人巨细胞病毒US31基因序列特征分析及B细胞表位预测

目的：分析人巨细胞病毒（HCMV）US31基因序列，预测US31基因编码蛋白的B细胞优势表位。方法：基于US31基因编码蛋白的氨基酸序列，结合亲水性参数、可及性参数、抗原性参数、柔韧性参数及二级结构方案对HCMV US31基因编码各型蛋白的B细胞表位进行预测，参照已建立的预测方法综合评价US31基因B细胞优势表位。结果：US31核苷酸序列变异较少，大部分是同义突变，氨基酸序列高度保守；其编码蛋白全长为162个氨基酸，相对分子质量20 kD，等电点7.66，为可溶性蛋白，二级结构中以无规则卷曲为主。经综合分析，US31基因的B细胞优势表位可能存在于氨基酸序列N端的5～19、32～47、58～68、110～124区段。结论：多参数预测HCMV pUS31的B细胞优势表位，为进一步研究蛋白特征、制备单克隆抗体及表位疫苗提供依据。

Analysis of the characteristics of gene seguence of human cytomegalovirus US31 and predication of B cell epitopes

Objective: To analyze the sequence of human cytomegalovirus US31 gene and predict the B cell epitopes of US31 protein. Methods: The hydrophilicity, accessibility, antigenicity and flexibility index were used to predict the potential B cell epitopes of protein based on the US31 amino acid sequence. Results: Most amino acid sequence of US31 was highly conserved while only a few strains had variation, and most of them were sense mutation. HCMV pUS31 contained 162 amino acid residues, the relative molecular mass was 20 kD and the isoelectric point was 7.66. It’s a soluble protein and its secondary structure occurred more frequently as random coil region. The predicted B-cell epitopes of the pUS31 might exist at N-terminal of amino acid sequence: 5~19, 32~47, 58~68, 110~124. Conclusion: The B-epitopes of pUS31 are predicted successfully, which provides a theoretic basis for the further study of protein characteristics, development of epitopes based vaccine, and preparation of monoclonal antibody against fusion protein.