模拟金黄色葡萄球菌脂磷壁酸表位的初步筛选与鉴定

摘要

Objective:To screen epitope mimics to lipoteichoic acid from a random 12-mer phage display peptide library and i-dentify the specificity of the mimotopes of LTA.Methods:The monoclonal antibody against LTA was used as a target to screen the 12-mer phage display peptide library and the specificity of phage clones were identified by sandwich ELISA.The amino acid sequences of positive phage clones were deduced from DNA sequencing.The specificity of synthetic peptide were identified by sandwich ELISA.Results:4 clones were obtained after 3 rounds of screening.Amino acid sequence analysis revealed four different types of mimotope sequence.A linear peptide (GHxDFRQxxQPS),named L2,which derived from positive sequence was synthesized.ELISA result indicates that L2 can bind to anti-LTA mAb specifically in a dose-dependent manner.Conclusion:The mimotopes of LTA were obtained by using the phage display technology.%目的：利用噬菌体展示肽库技术筛选并鉴定可模拟金黄色葡萄球菌细胞壁脂磷壁酸（LTA）的表位。方法：以抗LTA 单抗为靶分子，采用液相法对噬菌体12线性肽库进行3轮淘选，夹心ELISA 鉴定噬菌体克隆。对阳性噬菌体克隆进行DNA 测序并推导氨基酸序列，选择优势序列合成线性肽，ELISA 鉴定线性肽与抗体结合特异性。结果：经过三轮液相筛选，得到4个与抗LTA 单抗特异性结合的阳性噬菌体克隆，序列分析显示阳性克隆展示4种不同序列。选择与单抗结合最好的序列GHxDFRQxxQPS 合成线性短肽L2，ELISA 结果显示L2能够与抗LTA 单抗特异性结合。结论：利用噬菌体展示肽库筛选技术获得可模拟LTA 表位的序列。