分子内二硫键对HERV囊膜蛋白融合核心结构的影响

合胞素(Syncytin)是一类由人俘获的逆转录病毒囊膜蛋白,与胎盘的形态发生中细胞滋养层到合胞滋养层的分化过程十分相关。Syncytin与人免疫缺陷病毒I型(HIV-1)囊膜蛋白(Env)在结构上具有相似的特点,二者可能具有相似的膜融合机制。本文通过PCR对融合核心部位七肽重复区HR1和HR2之间linker中自然存在的一对保守的分子内二硫键进行定点突变,表达纯化该突变蛋白,并进行了相应的结构及稳定性探讨,通过与未突变蛋白的性质比较确证该分子内二硫键在蛋白结构的正确形成及稳定性上起着一定的作用。

Influence of Intramolecular Disulfide Bond on Fusion Core Structure of Envelope Protein of HERV

Syncytin, a captive retroviral envelope protein, is possibly involved in the morphogenesis of the placental syncytiotrophoblast layer generated by trophoblast cell fusion. It is found that syncytin and HIV-1 envelope proteins share similar structural profiles and membrane fusion mechanisms. In this article, we carried a mutagenesis by PCR to the conserved intramolecular disulfide bond of the linker between the heptad repeats HR1 and HR2 in the fusion core. We expressed and purified the mutant protein and subsequently the structure and stability were tested. After comparing the characteristics between the native and the mutant proteins, we got the concluded that this conserved intramolecular disulfide bond made a certain function in the correct protein structure formation and stability.