Xiang Zheng, Liu Bei-Yi, Hou Xiao-Rui, Xiang Jun-Jian, Fu Ning
Department of Immunology, Southern Medical University, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2010 Jun;26(6):530-2.
To screen peptide mimics of PSP (Paralytic shellfish poisoning) GTX2,3 from a random 12-mer phage display peptide library and to identify and characterize the specificity and accuracy of the peptide mimotope of GTX2,3.
The monoclonal antibody against GTX2,3 (mAb E(9);F(10);) 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 and blocking assay. The peptide sequences of positive phage clones were determined and analyzed by DNA sequencing. The affinity and specificity of synthetic peptide were identified by a competitive ELISA.
The 20 clones were identified to be specific reactivity with the mAb E(9);F(10);. Amino acid sequence analysis revealed seven different types of mimotope sequence, most of which contained a common motif DXLXPP(X presents random acid amino), X was random amino acid. The Phage No.2(phage 2), the clone with mimotope sequence WPSLDXLXPPSY showed the strongest binding, and inhibited the reactivity of the mAb with GTX2,3. Another ELISA result showed that synthetic peptide-1 (SP-1) which contain mimotope amino acid sequence was able to inhibit the mAb- GTX2,3 interaction.
The mimotope peptide of GTX2,3 is obtained by using the phage display technology. The results also showed that SP-1 bind to mAb E(9);F(10); at the same site as GTX2,3.
从一个随机的12肽噬菌体展示肽库中筛选麻痹性贝类毒素（PSP）GTX2,3的肽模拟物，并鉴定和表征GTX2,3肽模拟表位的特异性和准确性。
以抗GTX2,3单克隆抗体（mAb E(9);F(10);）为靶标筛选12肽噬菌体展示肽库，通过夹心ELISA和阻断试验鉴定噬菌体克隆的特异性。对阳性噬菌体克隆的肽序列进行DNA测序并分析。通过竞争ELISA鉴定合成肽的亲和力和特异性。
鉴定出20个与mAb E(9);F(10);具有特异性反应的克隆。氨基酸序列分析揭示了7种不同类型的模拟表位序列，其中大多数包含一个共同基序DXLXPP（X代表任意酸性氨基酸），X为任意氨基酸。噬菌体2号（噬菌体2），其模拟表位序列为WPSLDXLXPPSY，显示出最强的结合力，并抑制了mAb与GTX2,3的反应性。另一项ELISA结果表明，含有模拟表位氨基酸序列的合成肽-1（SP-1）能够抑制mAb与GTX2,3的相互作用。
利用噬菌体展示技术获得了GTX2,3的模拟表位肽。结果还表明，SP-1与mAb E(9);F(10);的结合位点与GTX2,3相同。
