从噬菌体短肽库中筛选单克隆抗体识别的抗原表位

将随机合成的寡聚核苷酸重组到噬菌体表面单价表达载体，构建了噬菌体随机八肽库。以抗原识别性明确的单克隆抗体９Ｅ１０固相化，对噬菌体短肽库进行了４～５轮“吸附－洗脱－扩增”的筛选，任选多个所获克隆进行ＥＬＩＳＡ检测。发现第４轮后６／２２个克隆可与９Ｅ１０结合，第５轮后１０／１０可与９Ｅ１０结合，此结合反应可被９Ｅ１０所针对的十肽抗原以及游离的９Ｅ１０特异性抑制。对所获阳性克隆进行ＤＮＡ序列测定发现，它们的序列可分为两种，其中一种序列与ｃ－ｍｙｃ十肽具有同源序列ＩＳＥｘｘＬ，而另一种的序列则完全不同。证实噬菌体表面单价表达体系用于构建噬菌体短肽库的有效性，为进一步筛选其它的具有高亲和力的特异性短肽打下了基础。

Selection of new epitope for monoclonal antibody from peptide library by phage display technology

Random peptide library displayed on the surface of bacteriophage has been used successfully to identify short peptides that bind to target molecules including monoclonal antibody,polyclonal antibody,and other binding molecules.It has potential applications in investigating the interaction between different proteins and finding new vaccine and drug candidates.Octapeptide library was constructed by use of monovalent phage display system and selected against coated monoclonal antibody 9E10,which recognized a continuous decapeptide epitope on c myc protein surface.After four to five rounds of panning,most of the eluted clones could bind to 9E10.Sequence analysis indicated that 2 different clones were obtained.Clone 1 had a consensus sequence,ISExxL,to c myc decapeptide and clone 2 was entirely different.Our results demonstrated that monovalent phage display system and micropanning method could be successfully used in peptide library.