Tobola Felix, Sylvander Elise, Gafko Claudia, Wiltschi Birgit
Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria.
Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria.
Interface Focus. 2019 Apr 6;9(2):20180072. doi: 10.1098/rsfs.2018.0072. Epub 2019 Feb 15.
Lectins are carbohydrate-binding proteins with specificity for their target ligands. They play diverse roles in cellular recognition and signalling processes, as well as in infections and cancer metastasis. Owing to their specificity, lectins find application in biotechnology and medicine, e.g. for blood group typing, purification of glycoproteins or lipids and as markers that target cancer cells. For some applications, lectins are immobilized on a solid support, or they are conjugated with other molecules. Classical protein conjugation reactions at nucleophilic amino acids such as cysteine or lysine are often non-selective, and the site of conjugation is difficult to pre-define. Random conjugation, however, can interfere with protein function. Therefore, we sought to equip lectins with a unique reactive handle, which can be conjugated with other molecules in a pre-defined manner. We site-specifically introduced non-canonical amino acids carrying bioorthogonal reactive groups into several lectins. As a proof of principle, we conjugated these 'clickable lectins' with small molecules. Furthermore, we conjugated lectins with different ligand specificities with one another to produce superlectins. The 'clickable lectins' might be useful for any process where lectins shall be conjugated with another module in a selective, pre-defined and site-specific manner.
凝集素是对其靶配体具有特异性的碳水化合物结合蛋白。它们在细胞识别和信号传导过程中以及在感染和癌症转移中发挥着多种作用。由于其特异性，凝集素在生物技术和医学中得到应用，例如用于血型分型、糖蛋白或脂质的纯化以及作为靶向癌细胞的标记物。对于某些应用，凝集素被固定在固体支持物上，或者与其他分子偶联。在亲核氨基酸（如半胱氨酸或赖氨酸）上进行的经典蛋白质偶联反应通常是非选择性的，并且偶联位点难以预先确定。然而，随机偶联可能会干扰蛋白质功能。因此，我们试图为凝集素配备一种独特的反应性手柄，使其能够以预先定义的方式与其他分子偶联。我们将携带生物正交反应基团的非天然氨基酸位点特异性地引入到几种凝集素中。作为原理验证，我们将这些“可点击凝集素”与小分子偶联。此外，我们将具有不同配体特异性的凝集素相互偶联以产生超级凝集素。“可点击凝集素”可能对任何需要以选择性、预先定义和位点特异性方式将凝集素与另一个模块偶联的过程都有用。
