Rabies is a fatal zoonosis which could affect all mammals. Glycoprotein (G protein) from the rabies virus plays an important role in the binding of virus to target cells. However, expression of the G protein with native conformation has been a great challenge for many years. In this study, we solved this problem by replacing the original signal peptide of rabies virus G protein with the one from the heavy chain of human IgG. The expression levels of recombinant G protein dramatically increased from a few μg/L to 50 mg/L in the culture supernatants. The identity of the recombinant G protein was confirmed by western blotting using both 6XHis mAb 6E2 and rabies G protein mAb 7G3. The correct conformation of the recombinant G protein was shown by using rabies virus neutralizing antibodies. In addition, the recombinant G protein had immune-reactivities with mice sera raised against rabies vaccines and vice versa. Taken together, our data suggested that by replacing the signal peptide, the expression level of the G protein with native conformation could be significantly improved. This would help the development of a rabies subunit vaccine, structural studies of rabies G protein, elucidation of the signal pathway of RABV infection.

中文翻译：

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狂犬病毒糖蛋白表达和表征的新策略。

狂犬病是一种致命的人畜共患病，可能影响所有哺乳动物。狂犬病毒的糖蛋白（G蛋白）在病毒与靶细胞的结合中起重要作用。然而，多年来以天然构象表达G蛋白一直是巨大的挑战。在这项研究中，我们通过用人IgG重链中的一种替代狂犬病毒G蛋白的原始信号肽解决了这一问题。在培养上清液中，重组G蛋白的表达水平从几微克/升急剧增加到50毫克/升。重组G蛋白的身份通过6XHis mAb 6E2和狂犬病G蛋白mAb 7G3的蛋白质印迹证实。通过使用狂犬病毒中和抗体显示了重组G蛋白的正确构象。此外，重组G蛋白与抵抗狂犬病疫苗的小鼠血清具有免疫反应性，反之亦然。两者合计，我们的数据表明，通过取代信号肽，具有天然构象的G蛋白的表达水平可以得到显着提高。这将有助于狂犬病亚单位疫苗的开发，狂犬病G蛋白的结构研究，阐明RABV感染的信号途径。