PURIFICATION AND CHEMICAL CHARACTERIZATION OF MEMBRANE-GLYCOPROTEINS FROM RAT THYMOCYTES AND BRAIN, RECOGNIZED BY MONOCLONAL-ANTIBODY MRC-OX2
PURIFICATION AND CHEMICAL CHARACTERIZATION OF MEMBRANE-GLYCOPROTEINS FROM RAT THYMOCYTES AND BRAIN, RECOGNIZED BY MONOCLONAL-ANTIBODY MRC-OX2
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DOI：
10.1111/j.1432-1033.1982.tb07070.x
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
WARD, HA
中科院分区：
文献类型：
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作者：
BARCLAY, AN;WARD, HA
MRC OX 2单克隆抗体识别存在于大鼠胸腺细胞、脑、淋巴器官中的滤泡树突状细胞、血管内皮、一些平滑肌和B淋巴细胞上的抗原。经脱氧胆酸钠增溶、MRC OX 2抗体亲和层析和凝胶过滤，从脑和胸腺中纯化了OX 2抗原。纯化的脑和胸腺细胞OX 2抗原是糖蛋白，通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳[SDS-PAGE]测定，其表观分子量（道尔顿）分别为41，000和47，000。用放射免疫分析法和组织切片免疫过氧化物酶染色法分析兔抗血清。脑和胸腺细胞OX 2抗原与其他组织上的抗原非常相似。显然，这种不寻常的分布模式不是MRC OX 2抗体偶然交叉反应的结果，因为预期兔血清识别抗原上的决定簇多于单克隆抗体识别的决定簇。脑和胸腺OX 2抗原的氨基酸组成非常相似，但没有区别。碳水化合物组成显示，OX 2抗原是高度糖基化的，其中脑OX 2抗原含有24%的碳水化合物，胸腺细胞OX 2抗原含有33%的碳水化合物。两种OX 2抗原均含有N-连接至天冬酰胺的典型结构的碳水化合物残基，但缺乏半乳糖胺，表明不存在O-连接结构。胸腺细胞OX 2含有较高水平的半乳糖和唾液酸，但岩藻糖比脑OX 2少。观察到类似的差异，脑和胸腺细胞Thy-1抗原，也观察到合并糖蛋白纯化的小扁豆凝集素亲和层析从这些组织，反映了糖基化的模式在2个组织的总体差异。OX 2抗原与Thy-1抗原在其奇怪的分布模式、SDS-PAGE上的特征性迁移和碳水化合物组成方面显示出许多相似之处。OX 2抗原与Thy-1抗原一样，可能与IG结构域具有同源性. OX 2抗原在组织组织所需的细胞相互作用中的可能作用进行了讨论。
The MRC OX 2 monoclonal antibody recognizes antigens present on rat thymocytes, brain, follicular dendritic cells in lymphoid organs, vascular endothelium, some smooth muscle and B-lymphocytes. The OX 2 antigens recognized by this antibody were purified from brain and thymus, by solubilization with sodium deoxycholate, affinity chromatography with MRC OX 2 antibody and gel filtration. The purified brain and thymocyte OX 2 antigens were glycoproteins with apparent MW [in daltons] of 41,000 and 47,000, respectively, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis [SDS-PAGE]. Rabbit antisera raised against the purified antigens were analyzed by radioimmunoassay and immunoperoxidase-staining of tissue sections. The brain and thymocyte OX 2 antigens were antigenically very similar to those on the other tissues. Evidently, the unusual pattern of distribution was not the result of fortuitous cross-reaction of the MRC OX 2 antibody, as the rabbit sera would be expected to recognize more determinants on the antigen than that recognized by the monoclonal antibody. The amino acid compositions of brain and thymus OX 2 antigens were very similar but with no distinguishing features. Carbohydrate compositions showed that the OX2 antigens were highly glycosylated, with brain OX 2 antigen containing 24% and thymocyte OX 2 antigen 33% by weight of carbohydrate. Both OX 2 antigens contained carbohydrate residues typical of structures N-linked to asparagine but lacked galactosamine, indicating the absence of O-linked structures. Thymocyte OX 2 contained higher levels of galactose and sialic acid but less fucose than brain OX 2. Similar differences were observed for brain and thymocyte Thy-1 antigens and were also observed in pooled glycoproteins purified by lentil lectin affinity chromatography from these tissues, reflecting overall differences in the patterns of glycosylation in the 2 tissues. The OX 2 antigens showed many similarities to Thy-1 antigens in their odd patterns of distribution, characteristic migration on SDS-PAGE, and carbohydrate compositions. OX 2 antigens, like Thy-1 antigens, may have homologies with Ig domains. A possible role of OX 2 antigens in cell interactions necessary for tissue organization is discussed.