Division of Livestock Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, 150001, PR China.
J Microbiol. 2011 Feb;49(1):94-101. doi: 10.1007/s12275-011-0134-1. Epub 2011 Mar 3.
VP2 is a structural protein of the foot-and-mouth disease virus (FMDV). In this study, a FMDV serotype-in-dependent monoclonal antibody (MAb), 4B2, was generated. By screening a phage-displayed random 12-peptide library, we found positive phages displaying the consensus motif ETTXLE (X is any amino acid (aa)), which is highly homologous to (6)ETTLLE(11) at the N-terminus of the VP2 protein. Subsequently, a series of GST-fusion proteins expressing a truncated N-terminus of VP2 were examined by western blot analysis using the MAb 4B2. The results indicated that the motif (6)ETTLLE(11) of VP2 may be the minimal requirement of the epitope recognized by 4B2. Moreover, a 12-aa peptide (2)KKTEETTLLEDR(13) was shown to be the minimal unit of the epitope with maximal binding activity to 4B2. Alanine-scanning analysis demonstrated thatThr(7), Thr(8), and Leu(10) are the functional residues of the 4B2 epitope Glu(6) and Leu(9) are required residues, and Glu(11) plays a crucial role in the binding of MAb 4B2. The fine mapping of the epitope indicated that MAb 4B2 has the potential to be used in FMDV diagnosis.
VP2 是口蹄疫病毒（FMDV）的一种结构蛋白。在这项研究中，生成了一种 FMDV 血清型非依赖性单克隆抗体（MAb）4B2。通过筛选噬菌体展示的随机 12 肽文库，我们发现了展示共有基序 ETTXLE（X 是任何氨基酸（aa））的阳性噬菌体，该基序与 VP2 蛋白 N 端的（6）ETTLLE（11）高度同源。随后，使用 MAb 4B2 通过 Western blot 分析检测了表达 VP2 截断 N 端的一系列 GST 融合蛋白。结果表明，VP2 的基序（6）ETTLLE（11）可能是 4B2 识别的表位的最小要求。此外，显示出最大结合活性的 12 个氨基酸肽（2）KKTEETTLLEDR（13）被证明是表位的最小单位。丙氨酸扫描分析表明，Thr（7）、Thr（8）和 Leu（10）是 4B2 表位 Glu（6）的功能残基，Leu（9）是必需残基，Glu（11）在 MAb 4B2 的结合中起关键作用。表位的精细定位表明，MAb 4B2 有可能用于 FMDV 的诊断。
