Department of Biochemistry and Food Chemistry, University of Turku, 20520 Turku, Finland.
Protein Eng Des Sel. 2013 Oct;26(10):683-93. doi: 10.1093/protein/gzt037. Epub 2013 Aug 21.
In directed evolution experiments, a single randomization scheme of an antibody gene does not provide optimal diversity for recognition of all sizes of antigens. In this study, we have expanded the recognition potential of our universal library, termed ScFvP, with a second distinct diversification scheme. In the second library, termed ScFvM, diversity was designed closer to the center of the antigen binding site in the same antibody framework as earlier. Also, the CDR-H3 loop structures were redesigned to be shorter, 5-12 aa and mostly without the canonical salt bridge between Arg106H and Asp116H to increase the flexibility of the loop and to allow more space in the center of the paratope for binding smaller targets. Antibodies were selected from the two libraries against various antigens separately and as a mixture. The origin and characteristics of the retrieved antibodies indicate that complementary diversity results in complementary functionality widening the spectrum of targets amenable for selection.
在定向进化实验中，单一的抗体基因随机化方案并不能为识别所有大小的抗原提供最佳的多样性。在这项研究中，我们使用第二种不同的多样化方案扩展了我们的通用文库 ScFvP 的识别潜力。在第二个文库 ScFvM 中，多样性设计更接近抗原结合位点的中心，位于与早期相同的抗体框架内。此外，CDR-H3 环结构被重新设计为更短，5-12 个氨基酸，并且大多没有 Arg106H 和 Asp116H 之间的经典盐桥，以增加环的灵活性，并在抗原结合位的中心允许更多的空间用于结合较小的靶标。针对各种抗原分别和混合，从两个文库中选择了抗体。回收抗体的起源和特征表明互补多样性产生互补功能，拓宽了可选择的目标范围。
