Recently, there has been an increasing interest in site-specific modifications of antibodies used in immunoassays for disease diagnosis and as antibody therapeutics, such as antibody-drug conjugates. Previously, we established a site-specific chemical conjugation system using an IgG-Fc binding chemical conjugation affinity peptide (CCAP). CCAP could be used only for the modification of human IgG owing to the lack of affinity of CCAP to rodent IgG molecules. In this study, novel CCAP reagents are proposed, which can be used for both human and mouse IgG, based on the Staphylococcus aureus protein A domain-derived affinity peptides Z34C and Z33. Compared to the activity of a conventional randomly modified antibody, mouse IgG modified using this method had favorable features in two immunoassays, demonstrating the advantages of the proposed CCAP method in preserving antibody functionality during conjugation.

中文翻译：

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通过亲和肽进行免疫测定的IgG抗体的新型位点特异性化学偶联。

近来，人们对用于免疫分析中用于疾病诊断和用作抗体治疗剂的抗体（例如抗体-药物缀合物）的抗体的位点特异性修饰越来越感兴趣。以前，我们使用IgG-Fc结合化学结合亲和力肽（CCAP）建立了位点特异性化学结合系统。由于CCAP与啮齿类动物IgG分子缺乏亲和力，因此CCAP仅可用于修饰人IgG。在这项研究中，基于金黄色葡萄球菌，提出了新型CCAP试剂，可用于人和小鼠IgG蛋白A结构域衍生的亲和力肽Z34C和Z33。与常规随机修饰抗体的活性相比，使用此方法修饰的小鼠IgG在两次免疫测定中均具有良好的功能，这表明了所提出的CCAP方法在缀合过程中保留抗体功能方面的优势。