Krotkiewski H, Nilsson B, Svensson S
Department of Carbohydrate Chemistry, University of Lund, Sweden.
Eur J Biochem. 1989 Sep 1;184(1):29-38. doi: 10.1111/j.1432-1033.1989.tb14986.x.
A mouse monoclonal IgM antibody, directed against human blood group B determinant, was isolated from hybridoma culture growth medium. Chemical analysis indicated presence of N- and O-linked oligosaccharides. The N- and O-linked carbohydrate chains were liberated using two different conditions of reductive alkaline degradation. Structural analysis was carried out on the isolated chains using chemical analysis, 500-MHz 1H-NMR spectroscopy and fast-atom-bombardment mass spectrometry. The following composite structures of the N-linked chains were found: (formula; see text) where R = OH for biantennary structures and R = Neu5Ac alpha 2-3Gal beta 1-4 GlcNAc beta 1- or Neu5Ac alpha 2-3Gal beta 1-3[Neu5Ac alpha 2-6]GlcNAc beta 1- for triantennary structures. The O-linked oligosaccharides, found in the light chains, were shown to have the structure Neu5Ac alpha 2-3Gal beta 1-3GalNAc. The native IgM antibody could be separated on a concanavalin-A-Sepharose column into two subfractions, differing in the presence of a high-mannose-type oligosaccharide.
从杂交瘤细胞培养液中分离出一种针对人血型B抗原决定簇的小鼠单克隆IgM抗体。化学分析表明存在N-连接和O-连接的寡糖。利用两种不同的还原性碱性降解条件释放N-连接和O-连接的碳水化合物链。使用化学分析、500兆赫兹1H-NMR光谱和快原子轰击质谱对分离出的链进行结构分析。发现N-连接链的以下复合结构：（分子式；见正文）其中对于双天线结构R = OH，对于三天线结构R = Neu5Acα2-3Galβ1-4GlcNAcβ1-或Neu5Acα2-3Galβ1-3[Neu5Acα2-6]GlcNAcβ1-。在轻链中发现的O-连接寡糖显示具有Neu5Acα2-3Galβ1-3GalNAc结构。天然IgM抗体可在伴刀豆球蛋白A-琼脂糖柱上分离成两个亚组分，它们在高甘露糖型寡糖的存在上有所不同。
