Davis T R, Schuler M L, Granados R R, Wood H A
Boyce Thompson Institute for Plant Research, Ithaca, NY 14853.
In Vitro Cell Dev Biol Anim. 1993 Nov;29A(11):842-6. doi: 10.1007/BF02631361.
The processing of the N-linked oligosaccharide modifying a secreted alkaline phosphatase glycoprotein (SEAP) expressed with a recombinant Autographa californica nuclear polyhedrosis virus was evaluated in insect cell lines established from Spodoptera frugiperda, Trichoplusia ni, and Mamestra brassicae. Studies with Endoglycosidase H (Endo H), which removes high-mannose oligosaccharides, revealed that 79% of the intracellular SEAP produced in the M. brassicae-derived MB0503 cell line was Endo H resistant. The commonly used S. frugiperda Sf21 and Sf9 cell lines produced 44 and 21% Endo H-resistant intracellular SEAP, respectively. Detection of oligosaccharide moieties with lectins, which selectively recognize terminal sugars, identified only mannose residues on SEAP expressed in the six insect cell lines. However, the oligosaccharide moiety of SEAP expressed in a Chinese hamster ovary cell line contained sialic acid. Therefore, when expressed in mammalian cells, the oligosaccharide present on SEAP is processed into complex oligosaccharide, but in insect cells it is of the high-mannose type. Studies with inhibitors of the initial oligosaccharide processing steps demonstrated that all six cell lines possessed glycosidase I/II and mannosidase I activity and that glycosylation was required for secretion.
利用重组苜蓿银纹夜蛾核型多角体病毒表达的分泌型碱性磷酸酶糖蛋白（SEAP）的N-连接寡糖加工过程，在源自草地贪夜蛾、粉纹夜蛾和甘蓝夜蛾的昆虫细胞系中进行了评估。用可去除高甘露糖寡糖的内切糖苷酶H（Endo H）进行的研究表明，在源自甘蓝夜蛾的MB0503细胞系中产生的细胞内SEAP，79%对Endo H具有抗性。常用的草地贪夜蛾Sf21和Sf9细胞系分别产生了44%和21%对Endo H具有抗性的细胞内SEAP。用可选择性识别末端糖的凝集素检测寡糖部分，在六种昆虫细胞系中表达的SEAP上仅鉴定出甘露糖残基。然而，在中国仓鼠卵巢细胞系中表达的SEAP的寡糖部分含有唾液酸。因此，当在哺乳动物细胞中表达时，SEAP上存在的寡糖被加工成复杂寡糖，但在昆虫细胞中它是高甘露糖型的。对寡糖加工初始步骤抑制剂的研究表明，所有六种细胞系都具有糖苷酶I/II和甘露糖苷酶I活性，并且糖基化是分泌所必需的。
