Phage‐displayed synthetic antibody (Ab) repertoires have become a major source of affinity reagents for basic and clinical research. Specific Abs identified from such libraries are often screened as fragments antigen binding (Fabs) produced in bacteria, and those with desired biochemical characteristics are reformatted for production as full‐length immunoglobulin G (IgG) in mammalian cells. The conversion of Fabs to IgGs is a cumbersome and often rate‐limiting step in the development of Abs. Moreover, biochemical properties required for lead IgG development are not always shared by the Fabs, and these issues are not uncovered until a significant effort has been spent on Abs that ultimately will not be useful. Thus, there is a need for simple and rapid techniques to convert phage‐displayed Fabs to IgGs at an early stage of the Ab screening process. We report the generation of a highly diverse phage‐displayed synthetic single‐chain Fab (scFab) library, in which the light and heavy chains were tethered with an optimized linker. Following selection, pools of scFabs were converted to single‐chain IgGs (scIgGs) en masse, enabling facile screening of hundreds of phage‐derived scIgGs. We show that this approach can be used to rapidly screen for and select scIgGs that target cell‐surface receptors, and scIgGs behave the same as conventional IgGs.

中文翻译：

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噬菌体展示的单链 Fab 文库，针对单链 IgG 的快速生产进行了优化。

噬菌体展示的合成抗体 (Ab) 库已成为基础和临床研究亲和试剂的主要来源。从这些文库中鉴定出的特定抗体通常被筛选为细菌中产生的抗原结合片段 (Fab)，并且那些具有所需生化特征的抗体被重新格式化以在哺乳动物细胞中产生全长免疫球蛋白 G (IgG)。Fabs 到 IgGs 的转化是 Abs 开发过程中一个繁琐且通常是限速步骤。此外，先导 IgG 开发所需的生化特性并不总是由 Fab 共享，并且在对最终无用的 Ab 进行了大量努力之前，这些问题才会被发现。因此，需要在抗体筛选过程的早期阶段使用简单快速的技术将噬菌体展示的 Fab 转化为 IgG。我们报告了高度多样化的噬菌体展示合成单链 Fab (scFab) 库的生成，其中轻链和重链与优化的接头相连。选择后，scFab 池被集体转化为单链 IgG (scIgG)，从而能够轻松筛选数百种噬菌体衍生的 scIgG。我们表明，这种方法可用于快速筛选和选择靶向细胞表面受体的 scIgG，并且 scIgG 的行为与常规 IgG 相同。