Analysis of BAC_5 mcAb-Related Epitope Using Random Peptide library

作     者：肖锡宾 张昌卿 张颖 张如华 李经略 冯凯涛 孙韵 叶永照 Xiao Xibin;ZHANG Changqing;ZHANG Ying;ZHANG Ruhua;LI Jinglüe;FENG Kaitao;SUN Yun;YE Yongzhao

作者机构：广州中山大学肿瘤医院510060 

出 版 物：《The Chinese-German Journal of Clinical Oncology》 (中德临床肿瘤学杂志（英文版）)

年 卷 期：2003年第2卷第1期

页      面：39-41,61页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：ThisprojectwasfoundedbyHealthFoundationofGuangdongProvince(GrantNo.A1 9992 1 2 ) 

主　　题：epitope random peptide library monoclonal antibody nasopharyngeal carcinoma 

摘      要：Objective To identify epitope relating to BAC 5 mcAb, a kind of monoclonal antibody (mcAb) located on the surface of nasopharyngeal carcinoma (NPC) cells. Methods Using BAC 5 mcAb as a selected target, the 3 rounds of biopanning to a 12 mer random peptide library (RPL) presented by M13 phages were carried out. The positive M13 phage clones were chosen and confirmed with sandwich ELISA for antibody capture and competitive assay. The exogenous DNA fragments in the positive/negative M13 phages were sequenced to deduce and compare the order of the amino acids of exogenous peptides among the phage clones. Results 77% (35/45) of the phages eluted from the 3rd round of biopnning could be captured by BAC 5 mcAb. The 3 kinds of the peptides were displayed by M13 phages from the 8 positive clones identified with competitive assay. The same character of -P-V- structure existed near N-terminus of the 3 different peptides, i.e. -H-Q-S-H-Y-P-Y-P-V-V-S-L- (4/8) -Q-N-Q-A-W-F-S-Q-P-V-R-M- (3/8) and T-Q-A-Y-K-G-F-P-V-L-P-S- (1/8) in comparison with the peptide -N-H-Q-S-T-F-W-Q-K-W-T-A- displayed by M13 phages from the negative clones (6/6). Conclusion BAC 5 mcAb can recognize the 3 kinds of the peptides with-P-V-structure near N-terminus. These peptides mimic the structure of the epitope on the surface of NPC cells recognized by BAC 5 mcAb.