以5株传染性法氏囊病病毒(Infectious bursal disease virus,IBDV)单克隆抗体HNF1、HNF7、B34、2B1和2G8作为筛选分子,对噬菌体展示12肽库进行3轮"吸附-洗脱-扩增"淘洗,从每株单克隆抗体筛选到的噬菌斑中随机挑取12个单克隆蓝色噬菌斑,合计60个,用间接ELISA检测,A值大于1.00;用竞争抑制ELISA分析,单克隆抗体和IBDV抗原均能竞争抑制筛选12肽与固相包被单克隆抗体的反应,抑制率大于40%,表明在该12肽内含有IBDV抗原表位。选取35个单克隆噬菌斑,测定噬菌体gIII部分基因的核苷酸序列,确定了这5个含有不同IBDV抗原表位12肽的核苷酸和氨基酸序列。进一步将其与GenBank中IBDV基因组编码蛋白的氨基酸序列进行比较,发现2B1筛选肽有4个连续氨基酸残基Leu-Ala-Ser-Pro与IBDV基因组A片段编码多聚蛋白的第536-599氨基酸残基一致,推测2B1为线性表位;而HNF1、HNF7、B34和2G8筛选肽均没找到有3个以上连续氨基酸残基与IBDV蛋白序列相同之处,推测可能是构象依赖性表位。

Five monoclonal antibodies to Infectious bursal disease virus(IBDV),HNF1,HNF7,B34,2B1 and 2G8 were used to screen for binding peptides from peptide 12-mer phage display library.After three rounds of panning(absorption-elution-amplification),sixty positive monoclonal phages(twelve for each monoclonal antibody) were selected and the phage displayed 12-peptides were detected and identified with indirect ELISA(A value 1.00) and competitive inhibition ELISA(inhibition rate 40%).The results indicated that 12-peptides contained epitopes of IBDV.Thirty-five positive monoclonal phages were sequenced,and the sequences of nucleotides and amino acids of the five different epitopes on IBDV were determined and analyzed.Comparison with sequences of IBDV registered in GenBank,four continuous amino acid residues Leu-Ala-Ser-Pro of 2B1 selected peptide was homology with the sequence encoded by genome fragment A from 536 to 539.But HNF1,HNF7,B34 and 2G8 selected peptides had no more than three continuous amino acid residues s