Nettleton M Y, Kochan J P
Department of Inflammation and Autoimmune Diseases, Hoffmann-La Roche, Nutley, NJ 07110, USA.
Int Arch Allergy Immunol. 1995 May-Jun;107(1-3):328-9. doi: 10.1159/000237017.
The Fc region of immunoglobulin E (IgE) comprising the C epsilon 3 and C epsilon 4 domains (residues 329-547) is sufficient for binding to the high-affinity IgE Fc receptor (Fc epsilon RI alpha). Three potential N-linked glycosylation sites are present within the C epsilon 3 domain. To determine the effect of the glycosylation sites on IgE Fc synthesis and on Fc epsilon RI alpha binding, site-directed mutagenesis was performed. Mutant IgE Fc constructs were expressed in COS cells and analyzed for protein synthesis and secretion, and Fc epsilon RI alpha binding activity. We find that only N371 and N394 are glycosylated, and that the residues surrounding the glycosylation site at N394 are required for Fc epsilon RI alpha binding activity.
包含Cε3和Cε4结构域（第329 - 547位氨基酸残基）的免疫球蛋白E（IgE）的Fc区域足以与高亲和力IgE Fc受体（FcεRIα）结合。Cε3结构域内存在三个潜在的N - 糖基化位点。为了确定糖基化位点对IgE Fc合成及对FcεRIα结合的影响，进行了定点诱变。突变型IgE Fc构建体在COS细胞中表达，并分析其蛋白质合成、分泌及FcεRIα结合活性。我们发现只有N371和N394被糖基化，并且N394糖基化位点周围的氨基酸残基对于FcεRIα结合活性是必需的。
