利用噬菌体展示的线性12肽库从马抗SARS-CoV IgG筛选SARS-CoV的抗原表位。经生物淘洗富集的噬菌体克隆被测序。获得两个共有序列:DXXDP和TXTLL。它们分别与SARS-CoVN蛋白341-345和392-396位氨基酸序列高度同源。含共有序列的克隆在ELISA竞争抑制试验中与SARS-CoVN蛋白竞争结合马抗SARS-CoVIgG。将两个共有序列肽通过基因重组技术成功展示到大肠杆菌鞭毛,获得重组菌F1和F2。用重组菌F1和F2免疫接种试验Balb/c小鼠产生的血清均能与SARS-CoVN蛋白特异结合。说明DXXDP和TXTLL是SARS-CoVN蛋白的两个连续抗原表位。
The epitopes of SARS-CoV were screened from a 12-mer phage display random peptide library using anti-SARS-CoV horse polyclonal antibodies of as a target. The phage clones enriched in biopannings were sequenced. Two consensus sequences were obtained, DXXDP and TXTLL, which had close identity to the 341-345 aa and 392-396 aa of SARA-CoV N protein sequences,respectively. The phage clones with consensus sequences and the N protein were both recognized and bound by the antibodies in a competitive-inhibition ELISA test. The consensus sequence peptides were cloned and displayed on the bacterial flagellin. Balb/c mice were vaccinated using the reconstruted bacteria and the collected serum was shown to speccifically combined with SARS-CoV N protein. This confirmed that DXXDP and TXTLL are two continuous epitopes of SARS-CoV N protein.