目的探讨风疹病毒E2包膜糖蛋白中部分亮氨酸的突变对特异性细胞融合的影响。方法于E2蛋白中选取9个亮氨酸位点,采用基因定点突变的方法分别将其突变成丙氨酸,采用流式细胞术检测各突变株蛋白在细胞表面的表达效率,Giemsa染色法与指示基因法检测特异性细胞融合,血吸附实验检测其吸附活性。结果与野毒株蛋白相比,除L144A与L225A之外,其它突变株蛋白在细胞表面的表达效率均有不同程度的降低。排除各突变株蛋白在细胞表面表达效率变化的影响后,其引起的细胞融合效率均有不同程度的降低,其中位于E2蛋白氨基酸序列中间靠近氨基端的亮氨酸(L58、L105、L128与L144)突变时,其细胞融合效率降低更为明显,相应的血吸附效率也有所降低。结论E2蛋白中,其氨基酸序列中间靠近氨基端的蛋白区域(L58～L144)对引起的特异性细胞融合具有重要的作用。 Objective To investigate the effect of partial leucine mutation in E2 glycoprotein of rubella virus on cell-specific fusion. Methods Nine leucine sites of E2 protein were selected and mutated to alanine by site-directed mutagenesis. The efficiency of protein expression on each cell surface was measured by flow cytometry. The Giemsa staining Specific gene fusion with the indicator gene assay was used to detect the adsorption activity. Results Compared with the wild-type strain, except for L144A and L225A, the expression of all other mutant strains on the cell surface decreased to some extent. Excluding the effect of the mutant protein on cell surface expression efficiency, the cell fusion efficiency was reduced to some extent. The leucine (L58, L105, L128 and L144) located near the amino terminal in the middle of the amino acid sequence of E2 protein, Mutation, the cell fusion efficiency decreased more significantly, the corresponding blood adsorption efficiency has also been reduced. Conclusion Among the E2 proteins, the protein region (L58 ~ L144) near the amino terminal in the amino acid sequence plays an important role in the specific cell fusion.