IDENTIFICATION OF A PEPTIDE WHICH BINDS TO THE CARBOHYDRATE-SPECIFIC MONOCLONAL ANTIBODY-B3
IDENTIFICATION OF A PEPTIDE WHICH BINDS TO THE CARBOHYDRATE-SPECIFIC MONOCLONAL ANTIBODY-B3
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DOI：
10.1016/0378-1119(93)90151-r
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发表时间：
1993-06-15
期刊：
影响因子：
3.5
通讯作者：
PASTAN, I
中科院分区：
文献类型：
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作者：
HOESS, R;BRINKMANN, U;PASTAN, I
单克隆抗体（mAb）B3识别在许多腺癌细胞表面发现的抗原。虽然细胞抗原的结构是未知的，但使用具有已知碳水化合物部分的新糖蛋白的表位作图表明mAb B3与刘易斯（Y）（Le（Y））抗原反应[Pastan等人，Cancer Res. 51（1991）3781-3787]。我们已经使用mAb B3来选择肽，其使用在其表面上展示随机肽的丝状噬菌体文库来模拟碳水化合物结构。所选择的噬菌体编码序列APWLYGPA。合成相应的肽并测试其结合mAb B3的能力。发现该肽特异性抑制In-111标记的mAb B3与A431腺癌细胞的结合，以及抑制B3免疫毒素对这些细胞的杀伤。此外，Le（Y）碳水化合物，乳二岩藻四糖，能够与展示该肽的噬菌体竞争结合mAb B3。编码该肽的序列的丙氨酸扫描诱变表明，四个残基PWLY对于与mAb的结合至关重要。该序列与已知模拟碳水化合物结构的其他序列相似。
The monoclonal antibody (mAb) B3 recognizes an antigen found on the surface of many adenocarcinoma cells. While the structure of the cellular antigen is unknown, epitope mapping using neoglycoproteins with known carbohydrate moieties indicates that the mAb B3 reacts with the Lewis(Y) (Le(Y)) antigen [Pastan et al., Cancer Res. 51 (1991) 3781-3787]. We have used mAb B3 to select for peptides that mimic the carbohydrate structure using libraries of filamentous phage displaying random peptides on their surface. Phage that were selected coded for the sequence APWLYGPA. The corresponding peptide was synthesized and tested for its ability to bind to mAb B3. The peptide was found to inhibit specifically the binding of In-111-labeled mAb B3 to A431 adenocarcinoma cells, as well as to inhibit killing of these cells by a B3 immunotoxin. In addition, the Le(Y) carbohydrate, lactodifucotetraose, was able to compete with the phage displaying this peptide for binding to mAb B3. Alanine-scanning mutagenesis of the sequence coding for this peptide indicates that four residues, PWLY, were critical for binding to the mAb. The sequence is similar to other sequences known to mimic carbohydrate structures.