利用15肽随机肽库确定抗TNF单抗表位的研究

利用抗ＴＮＦ的Ｔ５单抗作为筛选配基，对经ＤＮＡ碱基组成分析证明具有良好随机性的１５肽库进行亲和筛选．经过三轮筛选后，以硝酸纤维素膜斑点印迹法观察到良好的富集效果．由第三轮挑选出的３１个克隆进行ＤＮＡ测序，结果推出的优势克隆的短肽为ＣＹＲＲＰＡＧＧＬＰＧＩＣＳＡ等，竞争性ＥＬＩＳＡ实验证明带有以上短肽的噬菌体与ＴＮＦ能竞争性地与Ｔ５单抗结合．该多肽可能是Ｔ５单抗所识别的模拟表位

Identifying Epitope of Monoclonal Antibody with Phage displayed Random Peptide Library

A 15 mer random peptide library displayed on pⅢ of fd phage was used for screening the epitope of monoclonal antibody against tumor necrosis facter(TNF α).At first,randomness of the library was well confirmed according to the analysis of nucleotides composition within the insert region.Then three rounds of biopanning were carried out and dot blot was used to estimating the enrichment.Thirty one clones from the third round were randomly selected.The insert DNA seqences of these clones were detected and the amino acid seqences were deduced.Twenty nine of 31 peptides,belonging to different six clones,were conformation constrained.But none homology sequence with TNF α was found.The competitive ELISA tests proved that phage borne CYRRPAGGLPGICSA was the most potent peptide inhibiting the binding of antibody (T 5 McAb)with TNF α.It indicated that this short peptide could specifically bind to the T 5McAb.So it is may be a mimetic epitope of the McAd.