Rumpold H, Rhodes G H, Bloch P L, Carson D A, Vaughan J H
J Immunol. 1987 Jan 15;138(2):593-9.
The Epstein-Barr nuclear antigen-1 (EBNA-1) is a protein containing a large glycine-alanine repeat that has been shown to be antigenic. Antibodies to EBNA-1 can be detected by means of immunoblotting. Preincubation of antisera with purified EBNA-1 protein inhibits the binding of IgG antibodies in this system, indicating that those epitopes detected by immunoblots are also accessible on the native molecule. A number of synthetic peptides the sequences of which were derived from the glycine-alanine repeating region of EBNA-1 and from regions adjacent to it also inhibited antibody binding to EBNA-1. These showed, however, a 1000-fold variation in their inhibitory activities. Peptides containing only glycine and alanine were the most effective inhibitors. The anti-EBNA-1 antibodies did not react with several other peptides representing sequences from unrelated proteins. At saturating concentrations of peptide 85 to 100% of anti-EBNA-1, antibody binding was inhibited in all sera tested with one exception. Similar results are obtained when antibody binding is assayed by an enzyme immunosorbent assay by using partially purified EBNA-1 to coat the plates. Thus the glycine-alanine region, either through its primary structure or through conformations assumed by this region, forms the major epitope(s) of the EBNA-1 molecule.
爱泼斯坦-巴尔核抗原1（EBNA-1）是一种含有大量甘氨酸-丙氨酸重复序列的蛋白质，已被证明具有抗原性。可通过免疫印迹法检测针对EBNA-1的抗体。用纯化的EBNA-1蛋白对抗血清进行预温育可抑制该系统中IgG抗体的结合，这表明免疫印迹法检测到的那些表位在天然分子上也是可及的。一些合成肽，其序列源自EBNA-1的甘氨酸-丙氨酸重复区域及其相邻区域，也能抑制抗体与EBNA-1的结合。然而，它们的抑制活性有1000倍的差异。仅含甘氨酸和丙氨酸的肽是最有效的抑制剂。抗EBNA-1抗体不与代表无关蛋白质序列的其他几种肽发生反应。在肽浓度饱和时，除一个例外，在所有测试血清中，85%至100%的抗EBNA-1抗体结合被抑制。当使用部分纯化的EBNA-1包被酶标板通过酶联免疫吸附测定法检测抗体结合时，也获得了类似结果。因此，甘氨酸-丙氨酸区域，无论是通过其一级结构还是通过该区域呈现的构象，形成了EBNA-1分子的主要表位。
