Matsuda H, Nakamura S, Ichikawa Y, Kozai K, Takano R, Nose M, Endo S, Nishimura Y, Arata Y
Tokyo Research Center, Teijin Limited, Japan.
Mol Immunol. 1990 Jun;27(6):571-9. doi: 10.1016/0161-5890(90)90076-c.
The structure of the Fc fragment of human IgG1 immunoglobulin is compared for the native and recombinant proteins. A recombinant human Fc fragment was expressed by an E. coli system [Kitai K., Kudo T., Nakamura S., Masegi T., Ichikawa Y. and Horikoshi K. (1988) Appl. Microbiol. Biotechnol. 28, 52-56]. The recombinant protein, which presumably lacks oligosaccharides, was used along with the native human Fc fragment obtained by proteolytic digestion of a myeloma IgG1 protein. 1H NMR has been employed along with circular dichroism and fluorescence spectroscopy to discuss the structure of these two types of proteins. It has been concluded that (1) the overall structure of the recombinant protein is quite similar to that of the native protein, which possesses asparagine-linked oligosaccharides, but (2) a significant difference in structure exists in the neighborhood of the glycosylation site. The difference in the effector functions for the two kinds of the Fc proteins has been briefly discussed in terms of the structural change detected by 1H NMR.
对人IgG1免疫球蛋白Fc片段的天然蛋白和重组蛋白的结构进行了比较。一种重组人Fc片段由大肠杆菌系统表达[北井K.、工藤T.、中村S.、真关T.、市川Y.和堀越K.（1988年）《应用微生物学与生物技术》28卷，第52 - 56页]。将可能缺乏寡糖的重组蛋白与通过骨髓瘤IgG1蛋白的蛋白水解消化获得的天然人Fc片段一起使用。采用了1H核磁共振以及圆二色性和荧光光谱来探讨这两种蛋白的结构。得出的结论是：（1）重组蛋白的整体结构与具有天冬酰胺连接寡糖的天然蛋白非常相似，但（2）在糖基化位点附近存在显著的结构差异。根据1H核磁共振检测到的结构变化，简要讨论了两种Fc蛋白在效应功能方面的差异。
