Introduction and binding mechanism
The Spot Nanobody, also termed Spot VHH, is derived from single-domain alpaca antibody fragments. The Spot Nanobody recognizes the Spot-Tag® sequence motif PDRVRAVSHWSS. Binding occurs when the Spot-Tag peptide is embedded on the surface of the Spot Nanobody and acts like a β-sheet extension of the Spot-VHH. Specificity is determined by interactions of the Spot-Nanobody’s side chains to the Spot-Tag peptide. Notably, the bound Spot-peptide is also clamped by two amino acid side chains of the Spot-Nanobody. This binding mechanism explains the high affinity of the Spot-Nanobody.
The Spot Nanobody for
- immunoprecipitation and affinity purification is coupled to beads: Spot-Trap®
- protein purification is coupled to agarose: Spot-Cap™
- immunofluorescence and Western blotting is coupled to fluorescent dyes: Spot-Label®
- immobilization and coupling via NHS Ester reaction: Spot VHH, recombinant binding protein
- Recombinantly produced for constant high quality
- Sequence known
- Structure determined
- Binding mechanism understood
Spot-Nanobody is better performing in many capture and detection applications than other antibodies. Most of these antibodies are conventional IgGs, which may suffer from stability and size. Spot-Nanobody however is small size to better access the Spot-Tag epitope. In addition, Spot-Nanobody is very stable and binds to Spot-Tag even under harsh conditions. Non-IgG type affinity reagents for affinity-tags can’t be used for detection and imaging of tagged proteins, whereas Spot-Nanobody has an outstanding performance in immunofluorescence and Western blotting. Spot-Nanobody is the first Nanobody/ peptide-tag that was applied in super-resolution microscopy.
| || |