The SNAP-tag is a protein fusion tag system used in molecular biology research, developed by New England Biolabs (NEB). It enables specific and covalent labeling of fusion proteins with various synthetic dyes or chemical probes.
Derived from O^6-alkylguanine-DNA alkyltransferase (AGT), a bacterial DNA repair enzyme, the SNAP-tag system involves mutating the active site of AGT to abolish its DNA repair function while retaining its ability to bind and covalently react with benzylguanine (BG) derivatives.
When a protein of interest is genetically fused to the SNAP-tag, it can be specifically labeled by incubating with a BG-conjugated dye or probe. This results in the covalent attachment of the dye or probe to the SNAP-tag fusion protein, enabling precise labeling and detection in various experimental settings, including live-cell imaging and flow cytometry.
The SNAP-tag system offers high specificity, minimal background labeling, and the ability to label proteins in living cells or in vitro. It has found wide applications in cell biology, neuroscience, and drug discovery research for tasks such as protein tracking, localization studies, and receptor-ligand binding assays.
- SNAP-tag and CLIP-tag are registered trademarks of New England Biolabs, Inc.
Reviews:
(1) Dreyer R, Pfukwa R, Barth S, Hunter R, Klumperman B. The Evolution of SNAP-Tag Labels. Biomacromolecules. 2023 Feb 13;24(2):517-530. doi: 10.1021/acs.biomac.2c01238. Epub 2023 Jan 6. PMID: 36607253.
(2) Hoelzel CA, Zhang X. Visualizing and Manipulating Biological Processes by Using HaloTag and SNAP-Tag Technologies. Chembiochem. 2020 Jul 16;21(14):1935-1946. doi: 10.1002/cbic.202000037. Epub 2020 Apr 2. PMID: 32180315; PMCID: PMC7367766.