Complementarity-determining regions (CDRs) are sites on the variable chains of antibodies responsible for binding to specific antigens. In this study, a short peptide probe for recognition of 2,4,6-trinitrotoluene (TNT), was identified by testing sequences derived from the CDRs of an anti-TNT monoclonal antibody. The major TNT-binding site in this antibody was identified in the heavy chain CDR3 by antigen docking simulation and confirmed by an immunoassay using a spot-synthesis based peptide array comprising amino acid sequences of six CDRs in the variable region. A peptide derived from heavy chain CDR3 (RGYSSFIYWF) bound to TNT with a dissociation constant of 1.3 μM measured by surface plasmon resonance. Substitution of selected amino acids with basic residues increased TNT binding while substitution with acidic amino acids decreased affinity, an isoleucine to arginine change showed the greatest improvement of 1.8-fold. The ability to create simple peptide binders of volatile organic compounds from sequence information provided by the immune system in the creation of an immune response will be beneficial for sensor developments in the future.

中文翻译：

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抗TNT单克隆抗体衍生的短肽探针的基于阵列的合理设计

互补决定区（CDR）是抗体可变链上负责与特定抗原结合的位点。在这项研究中，通过测试衍生自抗TNT单克隆抗体CDR的序列，鉴定出了识别2,4,6-三硝基甲苯（TNT）的短肽探针。通过抗原对接模拟在重链CDR3中鉴定了该抗体中的主要TNT结合位点，并通过免疫测定法进行了证实，该方法使用了基于斑点合成的肽阵列，该阵列在可变区中包含6个CDR的氨基酸序列。通过表面等离振子共振测量，衍生自重链CDR3（RGYSSFIYWF）的肽以1.3μM的解离常数与TNT结合。用碱性残基取代所选氨基酸可增强TNT结合，而用酸性氨基酸取代则可降低亲和力，从异亮氨酸到精氨酸的变化显示最大的改善是1.8倍。从免疫系统提供的序列信息中创建挥发性有机化合物的简单肽结合剂的能力，将有助于免疫反应的发展。