Ota A, Seki J, Liu X L, Zhao Y, Wang X, Kondo K, Sakato N, Kinoshita T, Fujio H
Department of Immunoregulation, Osaka University.
J Biochem. 1993 Mar;113(3):314-20. doi: 10.1093/oxfordjournals.jbchem.a124045.
The specificity of hen egg-white lysozyme (HEL)-reactive rabbit antibodies induced by the peptide loop I.II (sequences 57-107 containing Cys64-Cys80 and Cys76-Cys94) of HEL was clarified by analyzing their cross-reactions with various avian lysozymes and their reaction with synthetic peptides (sequences 59-82) in which alanine was substituted for the amino acid at certain positions. The Arg-68 residue of HEL plays a dominant role in the binding, while Gly-71, Ser-72, Arg-73, and Pro-79 also contribute to the binding of two anti-Ploop I.II antibodies (rabbit number 125 and 126). These residues, although remote in sequence, are grouped together in the crystal structure of HEL and may form an area of contact with the antibody. Contributions by Trp-63, Ile-78, and Asn-77 to the binding of the two antibodies to HEL were excluded. These results support the idea that the anti-Ploop I.II antibodies recognize a conformational type of epitope which is similar to that of native HEL. The immunogenicity of the reduced and alkylated form of Ploop I.II was also tested, but it failed to induce an HEL-reactive antibody.
通过分析鸡卵清溶菌酶（HEL）的肽环I.II（包含Cys64 - Cys80和Cys76 - Cys94的57 - 107位序列）诱导产生的兔抗HEL抗体与各种禽溶菌酶的交叉反应以及它们与在特定位置用丙氨酸替代氨基酸的合成肽（59 - 82位序列）的反应，阐明了这些抗体的特异性。HEL的Arg - 68残基在结合中起主导作用，而Gly - 71、Ser - 72、Arg - 73和Pro - 79也有助于两种抗Ploop I.II抗体（兔编号125和126）的结合。这些残基虽然在序列上相隔较远，但在HEL的晶体结构中聚集在一起，可能形成与抗体的接触区域。排除了Trp - 63、Ile - 78和Asn - 77对两种抗体与HEL结合的贡献。这些结果支持了抗Ploop I.II抗体识别与天然HEL相似的构象型表位的观点。还测试了还原烷基化形式的Ploop I.II的免疫原性，但它未能诱导出抗HEL反应性抗体。
