SNAP-tag

SNAP-tag is a 182 residue polypeptide (19.4 kDa) that can be fused to any protein of interest and further specifically and covalently tagged with a suitable ligand, such as a fluorescent dye.

Since its introduction, SNAP-tag has found numerous applications in biochemistry and for the investigation of the function and localisation of proteins and enzymes in living cells.

The SNAP-tag® protein is an engineered version of the ubiquitous mammalian enzyme AGT,[2] encoded in humans by the O-6-methylguanine-DNA methyltransferase (MGMT) gene.

A split-SNAP-tag version suitable for protein complementation assay and protein-protein interaction studies was later developed.

[5] Apart from fluorescence microscopy, SNAP-tag and CLIP-tag have proven useful in the elucidation of numerous biological processes, including the identification of multiprotein complexes using various approaches such as FRET,[6] cross-linking,[6] proximity ligation assay,[7] as well as the purification of insulin secretory granules of distinct age by doing pulse-chase experiments [8] Other application include the measurement of protein half-lives in vivo,[9] and small molecule-protein interactions.