The biotin-streptavidin interaction is among the strongest known in nature. Here, we report the site-directed incorporation of biotin and 2-iminobiotin bearing non-canonical amino acids (ncAA) into proteins. 2-Iminobiotin lysine was employed for protein purification based on the pH-dependent dissociation constant to streptavidin. Using the high affinity binding of biotin lysine, we could specifically isolate the bacterial protein RecA and analyze its interaction partners. Furthermore, we successfully transferred our biotinylation approach to mammalian cells. The stringent control over the biotinylation site and the tunable affinity between ncAAs and streptavidin by the different biotin-analogs makes this approach an attractive tool for protein interaction studies, protein immobilization and the generation of well-defined protein drug conjugates.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Marie-Theres Vielberg (TUM) for providing AnbuTAG71. This study was supported by the King Abdullah University of Science and Technology (KAUST). This work was performed in the framework of the German Research Foundation (DFG) Sonderforschungsbereich 1035, projects A02, B10, and B11. YGM gratefully acknowledges funding via a DAAD Ph.D. scholarship. KL and MJF are Rudolf Mößbauer Tenure Track Professors and as such gratefully acknowledge funding through the Marie Curie COFUND program and the Technical University of Munich Institute for Advanced Study, funded by the German Excellence Initiative and the European Union Seventh Framework Program under Grant Agreement 291763.