Institute for Organic Chemistry and Biochemistry, Technische Universität Darmstadt, Alarich-Weiss-Strasse 4, 64287, Darmstadt, Germany.
Department of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Stephanstrasse 7, 64295, Darmstadt, Germany.
Chembiochem. 2019 Sep 16;20(18):2411-2419. doi: 10.1002/cbic.201900101. Epub 2019 Aug 20.
Microbial transglutaminase (mTG) has recently emerged as a powerful tool for antibody engineering. In nature, it catalyzes the formation of amide bonds between glutamine side chains and primary amines. Being applied to numerous research fields from material sciences to medicine, mTG enables efficient site-specific conjugation of molecular architectures that possess suitable recognition motifs. In monoclonal antibodies, the lack of native transamidation sites is bypassed by incorporating specific peptide recognition sequences. Herein, we report a rapid and efficient mTG-catalyzed bioconjugation that relies on a novel recognition motif derived from its native substrate Streptomyces papain inhibitor (SPI ). Improved reaction kinetics compared to commonly applied sequences were demonstrated for model peptides and for biotinylation of Her2-targeting antibody trastuzumab variants. Moreover, an antibody-drug conjugate assembled from trastuzumab that was C-terminally tagged with the novel recognition sequence revealed a higher payload-antibody ratio than the reference antibody.
微生物转谷氨酰胺酶（mTG）最近成为抗体工程的有力工具。在自然界中，它催化谷氨酰胺侧链和伯胺之间酰胺键的形成。mTG 被应用于从材料科学到医学等众多研究领域，能够有效地将具有合适识别模体的分子结构进行定点偶联。在单克隆抗体中，通过引入特定的肽识别序列来绕过缺乏天然转酰胺化位点的问题。在此，我们报告了一种快速有效的 mTG 催化生物偶联反应，该反应依赖于源自其天然底物链霉菌木瓜蛋白酶抑制剂（SPI）的新型识别模体。与常用序列相比，模型肽和针对 Her2 靶向抗体曲妥珠单抗变体的生物素化反应的动力学得到了改善。此外，通过新型识别序列将末端标记的 C 端的曲妥珠单抗组装成的抗体药物偶联物的载药-抗体比高于参比抗体。
