title: DNA-Templated Introduction of an Aldehyde Handle in Proteins.
abstract: Many medical and biotechnological applications rely on protein labeling, but a key challenge is the production of homogeneous and site-specific conjugates. This can rarely be achieved by simple residue-specific random labeling, but generally requires genetic engineering. Using site-selective DNA-templated reductive amination, we created DNA-protein conjugates with control over labeling stoichiometry and without genetic engineering. A guiding DNA strand with a metal-binding functionality facilitates site-selectivity by directing the coupling of a second reactive DNA strand in the vicinity of a protein metal-binding site. We demonstrate DNA-templated reductive amination for His6 -tagged proteins and metal-binding proteins, including IgG1 antibodies. We also used a cleavable linker between the DNA and the protein to remove the DNA and introduce a single aldehyde on the protein. This functions as a handle for further modifications with desired labels. In addition to directing the aldehyde positioning, the DNA provides a straightforward route for purification between reaction steps.
authors.affiliation: Center for DNA Nanotechnology, Department of Chemistry and iNANO, Aarhus University, Gustav Wieds Vej14, 8000, Aarhus C, Denmark.
authors.forename: Anne Louise B
authors.initials: AL
authors.lastname: Kodal
authors.affiliation: Center for DNA Nanotechnology, Department of Chemistry and iNANO, Aarhus University, Gustav Wieds Vej14, 8000, Aarhus C, Denmark.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Rosen
authors.affiliation: Center for DNA Nanotechnology, Department of Chemistry and iNANO, Aarhus University, Gustav Wieds Vej14, 8000, Aarhus C, Denmark.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Mortensen
authors.affiliation: Center for DNA Nanotechnology, Department of Chemistry and iNANO, Aarhus University, Gustav Wieds Vej14, 8000, Aarhus C, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Tørring
authors.affiliation: Center for DNA Nanotechnology, Department of Chemistry and iNANO, Aarhus University, Gustav Wieds Vej14, 8000, Aarhus C, Denmark. kvg@chem.au.dk.
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Gothelf
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000586:Amination; D001665:Binding Sites; D003432:Cross-Linking Reagents; D004247:DNA / Q000737:chemistry*; D008670:Metals; D011506:Proteins / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D003432:Cross-Linking Reagents; D008670:Metals; D011506:Proteins; D004247:DNA
keywords: DNA-templated chemistry; aldehydes; proteins; reductive amination; site-selectivity