Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review
Final published version, 6.82 MB, PDF document
Final published version
Camelid single-domain antibody fragments, also called nanobodies, constitute a class of binders that are small in size (~15 kDa) and possess antigen-binding properties similar to their antibody counterparts. Facile production of recombinant nanobodies in several microorganisms has made this class of binders attractive within the field of molecular imaging. Particularly, their use in super-resolution microscopy has improved the spatial resolution of molecular targets due to a smaller linkage error. In single-molecule localization microscopy techniques, the effective spatial resolution can be further enhanced by site-specific fluorescent labeling of nanobodies owing to a more homogeneous protein-to-fluorophore stoichiometry, reduced background staining and a known distance between dye and epitope. Here, we present a protocol for site-specific bioconjugation of DNA oligonucleotides to three distinct nanobodies expressed with an N- or C-terminal unnatural amino acid, 4-azido-L-phenylalanine (pAzF). Using copper-free click chemistry, the nanobody-oligonucleotide conjugation reactions were efficient and yielded highly pure bioconjugates. Target binding was retained in the bioconjugates, as demonstrated by bio-layer interferometry binding assays and the super-resolution microscopy technique, DNA points accumulation for imaging in nanoscale topography (PAINT). This method for site-specific protein-oligonucleotide conjugation can be further extended for applications within drug delivery and molecular targeting where site-specificity and stoichiometric control are required.
Original language | English |
---|---|
Article number | e159 |
Journal | Journal of Biological Methods |
Volume | 9 |
Issue | 1 |
Number of pages | 14 |
ISSN | 2326-9901 |
DOIs | |
Publication status | Published - Mar 2022 |
© 2013-2022 The Journal of Biological Methods, All rights reserved.
See relations at Aarhus University Citationformats
ID: 306312887