O-glycosylation in hinge region of mouse immunoglobulin G2b.
O-glycosylation in hinge region of mouse immunoglobulin G2b.
复制标题
小鼠免疫球蛋白 G2b 铰链区的 O-糖基化。
DOI：
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发表时间：
1994
影响因子：
4.8
通讯作者：
Y. Arata
中科院分区：
文献类型：
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作者：
Hahyung Kim;Y. Yamaguchi;K. Masuda;Chigusa Matsunaga;Kazuo Yamamoto;T. Irimura;N. Takahashi;K. Kato;Y. Arata
已知小鼠单克隆免疫球蛋白G2 b（IgG 2b）抗体含有两种形式的重链，其对蛋白酶攻击的敏感性不同。在本研究中，通过使用亲和柱含有唾液酸结合凝集素从怀槐种子，小鼠单克隆IgG 2b被成功地分离成三种表型，这是不同的唾液酸化程度的重链。在所有IgG 2b表型的N-连接寡糖中，几乎未检测到唾液酸化。赖氨酰内肽酶消化产物的洗脱曲线进行了比较的三种表型。在不同的保留时间洗脱的肽进行快速原子轰击质谱和氨基酸序列分析。结果显示，小鼠IgG 2b重链约40%在铰链区Thr-221 A处O-糖基化，主要由GalNAc、Gal和两个N-羟乙酰神经氨酸残基组成的四糖。我们认为O-糖基化使铰链区对重链的蛋白水解具有抵抗力。简要讨论了IgG 2b O-糖基化的治疗意义。
Mouse monoclonal immunoglobulin G2b (IgG2b) antibodies are known to contain two forms of the heavy chain that are different in susceptibility to the protease attack. In the present study, by use of an affinity column containing sialic acid-binding lectins from Maackia amurensis seeds, a mouse monoclonal IgG2b was successfully separated into three phenotypes, which are different in the degree of sialylation in the heavy chain. In the N-linked oligosaccharides from all of the IgG2b phenotypes, virtually no sialylation was detected. Elution profiles of the lysyl endopeptidase digestion products were compared for the three phenotypes. The peptides eluted at different retention times were subjected to fast atom bombardment-mass spectrometry and amino acid sequence analyses. It was revealed that approximately 40% of the heavy chain of the mouse IgG2b are O-glycosylated at Thr-221A in the hinge region, predominantly with a tetrasaccharide composed of GalNAc, Gal, and two N-glycolylneuraminic acid residues. We suggest that the O-glycosylation renders the hinge region resistant against the proteolyses of the heavy chain. A therapeutic significance of the O-glycosylation of IgG2b is briefly discussed.