Recombinant soluble trimeric influenza A virus hemagglutinins (HA) and tetrameric neuraminidases (NAs) have proven to be excellent tools to decipher biological properties. Receptor binding and sialic acid cleavage by recombinant proteins correlate satisfactorily compared to whole viruses. Expression of HA and NA can be achieved in a plethora of different laboratory hosts. For immunological and receptor interaction studies however, insect and mammalian cell expressed proteins are preferred due to the presence of N‐linked glycosylation and disulfide bond formation. Because mammalian‐cell expression is widely applied, an increased expression yield is an important goal. Here we report that using codon‐optimized genes and sfGFP fusions, the expression yield of HA can be significantly improved. sfGFP also significantly increased expression yields when fused to the N‐terminus of NA. In this study, a suite of different hemagglutinin and neuraminidase constructs are described, which can be valuable tools to study a wide array of different HAs, NAs and their mutants.

中文翻译：

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重组可溶性A型流感病毒血凝素和神经氨酸酶在哺乳动物细胞中的驱动程序。

重组可溶性三聚体A型流感病毒血凝素（HA）和四聚体神经氨酸酶（NAs）已被证明是破译生物学特性的极佳工具。与完整病毒相比，重组蛋白的受体结合和唾液酸切割令人满意。HA和NA的表达可以在许多不同的实验室宿主中实现。然而，对于免疫学和受体相互作用研究，昆虫和哺乳动物细胞表达的蛋白是优选的，因为存在N-联糖基化和二硫键形成。由于哺乳动物细胞表达得到广泛应用，因此提高表达产量是一个重要的目标。在这里我们报告说，使用密码子优化的基因和sfGFP融合体，可以显着提高HA的表达产量。当与NA的N端融合时，sfGFP还可显着提高表达产量。在这项研究中，描述了一套不同的血凝素和神经氨酸酶构建体，它们可能是研究各种不同的HA，NA及其突变体的有价值的工具。