We describe a facile and robust genetic selection for isolating full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of the genetically engineered Escherichia coli strain, SHuffle. The method is based on the transport of a bifunctional substrate comprised of an antigen fused to chloramphenicol acetyltransferase, which allows positive selection of bacterial cells co-expressing cytoplasmic IgGs called ‘cyclonals’ that specifically capture the chimeric antigen and sequester the antibiotic resistance marker in the cytoplasm. The selective power of this approach was demonstrated by facile isolation of novel complementarity-determining regions for a cyclonal that specifically recognized the basic-region leucine zipper domain of the yeast transcriptional activator protein Gcn4.

中文翻译：

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从大肠杆菌胞质中表达的组合文库中分离全长IgG抗体

我们描述了一种简便而强大的遗传选择，用于从在基因工程大肠杆菌菌株SHuffle的细胞质中表达的组合文库中分离全长IgG抗体。该方法基于包含与氯霉素乙酰基转移酶融合的抗原的双功能底物的转运，该底物允许共选择共表达胞质IgG的细菌细胞，称为``细胞周期蛋白''，这种细菌特异性地捕获嵌合抗原并隔离抗生素抗性标记细胞质。这种方法的选择性能力通过轻松分离出一个新的互补决定区域来证明，该区域可以特异性识别酵母转录激活蛋白Gcn4的基本区域亮氨酸拉链结构域。