MOLECULAR-CLONING OF CDNA FOR THE CARCINOMA-ASSOCIATED ANTIGEN GA733-2
MOLECULAR-CLONING OF CDNA FOR THE CARCINOMA-ASSOCIATED ANTIGEN GA733-2
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DOI：
10.1073/pnas.87.9.3542
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发表时间：
1990-05-01
影响因子：
11.1
通讯作者：
LINNENBACH, AJ
中科院分区：
文献类型：
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作者：
SZALA, S;FROEHLICH, M;LINNENBACH, AJ
由单抗GA733定义的GA733-2抗原是一种细胞表面40 kDa的糖蛋白，与各种来源的人类癌症有关。利用高效的COS细胞表达系统从结直肠癌细胞系的cDNA文库中分离出GA733-2抗原的分子克隆。用单抗进行免疫选择，获得了一个1.4kb碱基的cDNA族。通过免疫学和序列标准确定单个克隆的真实性。在氨基酸序列水平上，发现GA733-2与由单抗KS1/4定义的KSA抗原有99%的同源性。来自GA733相关基因GA733-1的氨基酸序列与GA733-2有49%的同源性。这两个GA733抗原胞外区的12个半胱氨酸残基的位置是保守的，疏水和亲水残基的总体分布也是保守的。GA733-2/KSA基因的1.45kb转录本在来自结直肠癌和胰腺癌的细胞系中表达。
Defined by monoclonal antibody GA733, the GA733-2 antigen is a cell surface 40-kDa glycoprotein associated with human carcinomas of various origins. Molecular clones for the GA733-2 antigen were isolated from a colorectal carcinoma cell line cDNA library using the high-efficiency COS cell expression system. A 1.4-kilobase cDNA species was enriched by immunoselection with monoclonal antibody. The authenticity of individual clones was established by immunologic and sequence criteria. At the amino acid sequence level, GA733-2 was found to be > 99% identical to the previously described KSA antigen defined by monoclonal antibody KS1/4. The amino acid sequence derived from the previously described GA733-related gene, GA733-1, was found to be 49% identical to GA733-2. The positions of 12 cysteine residues in the extracellular domains of the two GA733 antigens are conserved, as is the overall distribution of hydrophobic and hydrophilic residues. A 1.45-kilobase transcript of the GA733-2/KSA gene was found to be expressed in cell lines derived from colorectal and pancreatic carcinoma.