The Ok(a) blood group antigen is a marker for the M6 leukocyte activation antigen, the human homolog of OX-47 antigen, basigin and neurothelin, an immunoglobulin superfamily molecule that is widely expressed in human cells and tissues
The Ok(a) blood group antigen is a marker for the M6 leukocyte activation antigen, the human homolog of OX-47 antigen, basigin and neurothelin, an immunoglobulin superfamily molecule that is widely expressed in human cells and tissues
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DOI：
10.1002/eji.1830270414
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发表时间：
1997-04-01
影响因子：
5.4
通讯作者：
Parsons, SF
中科院分区：
文献类型：
--
作者：
Spring, FA;Holmes, CH;Parsons, SF
高频血型抗原Ok（a）携带在35-69 kDa的红细胞膜糖蛋白（gp）上，该糖蛋白广泛分布于不同来源的恶性细胞上。造血细胞和一系列正常人体组织的免疫染色显示Ok（a）gp广泛分布，似乎是非谱系限制性的，尽管某些组织显示分化相关的表达。用单克隆抗体A103通过免疫亲和层析从红细胞膜中纯化Ok（a）gp，并进行氨基酸序列分析。N-末端30个氨基酸与M6白细胞活化抗原（M6）的预测序列相同，M6是具有两个IgSF结构域的IG超家族（IgSF）成员。在大鼠（MRC OX-47或CE 9）、小鼠（basigin或gp 42）和鸡（HT 7或神经皮素）中存在同源物。通过对正常和Ok（a-）EBV转化的B细胞系的M6 cDNA进行测序，建立了Ok（a）突变的分子基础。M6 cDNA翻译部分的点突变G（331）AG --> AAG导致蛋白质Ok（a-）形式的第一个Ig样结构域中预测的E-92 --> K氨基酸改变。用正常或Ok（a-）cDNA转染小鼠NS-0细胞证实了蛋白的同一性，只有Ok（a-）转染子不能与单克隆抗Ok（a）Ab反应。
The high-frequency blood group antigen Ok(a) is carried on a red cell membrane glycoprotein (gp) of 35-69 kDa that is widely distributed on malignant cells of different origins. Immunostaining of hemopoietic cells and a range of normal human tissues demonstrated a wide distribution of the Ok(a) gp that appears to be nonlineage-restricted, although certain tissues show differentiation-related expression. Ok(a) gp was purified from red cell membranes by immunoaffinity chromatography using mAb A103 and amino acid sequence analysis was performed. The N-terminal 30 amino acids are identical to the predicted sequence of M6 leukocyte activation antigen (M6), a member of the Ig superfamily (IgSF) with two IgSF domains. There are homologs in rat (MRC OX-47 or CE9), in mouse (basigin or gp42), and in chicken (HT7 or neurothelin). The molecular basis of the Ok(a) mutation was established by sequencing M6 cDNA derived from normal and Ok(a-) EBV-transformed B cell lines. A point mutation in the translated portion of M6 cDNA, G(331)AG --> AAG gives rise to a predicted E-92 --> K amino acid change in the first Ig-like domain of the Ok(a-) form of the protein. Transfection of mouse NS-0 cells with normal or Ok(a-) cDNA confirmed the identity of the protein and only the Ok(a-) transfectants failed to react with monoclonal anti-Ok(a) Ab.