SNAP-tag2 for faster and brighter protein labeling.

ABSTRACT: SNAP-tag is a powerful tool for labeling proteins with synthetic fluorophores in bioimaging. However, its utility in live-cell applications can be constrained by its relatively slow labeling kinetics and the limited cell permeability of its substrates. Here, we introduce improved labeling substrates and an engineered SNAP-tag for faster labeling in vitro and in live cells. SNAP-tag2 presents a second-order rate constant with rhodamine substrates that approaches 10⁷ s^-1 M^-1, a 100-fold improvement over the corresponding SNAP-tag-substrate pairs. When labeled with highly fluorogenic dyes, SNAP-tag2 also shows a fivefold increase in fluorescence brightness relative to currently used SNAP-tag. The increased labeling kinetics and brightness of SNAP-tag2 translat

SUBMITTER: Kuhn S 

PROVIDER: S-EPMC12568630 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature