A Vinyl Sulfone‐Based Fluorogenic Probe Capable of Selective Labeling of PHGDH in Live Mammalian Cells

Abstract

Chemical probes are powerful tools for interrogating small molecule-target interactions. With additional fluorescence Turn-ON functionality, such probes might enable direct measurements of target engagement in live mammalian cells. DNS-pE (and its terminal alkyne-containing version DNS-pE2) is the first small molecule that can selectively label endogenous 3-phosphoglycerate dehydrogenase (PHGDH) from various mammalian cells. Endowed with an electrophilic vinyl sulfone moiety that possesses fluorescence-quenching properties, DNS-pE/DNS-pE2 became highly fluorescent only upon irreversible covalent modification of PHGDH. With an inhibitory property (in vitro K =7.4 μm) comparable to that of known PHGDH inhibitors, our probes thus offer a promising approach to simultaneously image endogenous PHGDH activities and study its target engagement in live-cell settings.

Recent advances in construction of small molecule-based fluorophore-drug conjugates

“…Consequently, probe 6 can be used for both in situ profiling and two-photon fluorogenic imaging of cellular enzyme activities. These successful examples, which are combined with no-washing drug imaging and chemoproteomics, have inspired researchers to develop multi-functional conjugates capable of providing more insightful information in drug discovery [ [36] , [37] , [38] ].…”

Emerging Applications of Fluorogenic and Non‐fluorogenic Bifunctional Linkers

“…For example, Yaoa nd co-workersr eported the SCF13 linker consisting of aq uenching vinyl sulfone and an onquenching propargyl moiety. [65] SCF13 selectively labels 3-phosphoglycerate dehydrogenase (PHGDH) [67] through the reactiono ft he vinyl sulfone and thiol moietiesi nP HGDH, leading to emission turn-on and imaging of endogenous PHGDH activity.I na ddition, the propargyl moiety of SCF13 was subsequently linked to commerciallya vailable azide-biotin (N 3 -biotin)t hrough the CuAAC reactionf or enrichmenta nd purification by streptavidin-coated beads (Figure 14 a). Zhou et al reported the azido-and hydrazine-functionalized SCF14 linker, [66] the emission of which was initially quenched by the hydrazine moiety through the PET mechanism [68] for the fluorogenic labelingo f5fC [69] by ah ydrazine-aldehyde reaction that enabled fluorescent visualization of PAGE bands.…”

“…In contrast to SCF linkers,D CF linkerso nly exhibit emission turn-onu pond ual reaction-enabled conjugate formation, allowingt he one-pot fabrication of bioconjugates and fluorescent assay.H owever,t he design and synthesis of profluoro- Figure 14. Hetero-bifunctional SCF linkers for both labeling and functionality.a)SCF13a nd b) SCF14s electively and fluorogenically label PHGDH [65] and 5-formylcytosine (5fC) [66] for in vivo imagingand PAGE visualization, respectively, followed by biotin functionalizationfor furtherenrichment and quantification. Figure 15.…”

“…The remaining nonquenching moiety could be utilized for further functionalization or purification purposes. For example, Yao and co‐workers reported the SCF13 linker consisting of a quenching vinyl sulfone and a nonquenching propargyl moiety . SCF13 selectively labels 3‐phosphoglycerate dehydrogenase (PHGDH) through the reaction of the vinyl sulfone and thiol moieties in PHGDH, leading to emission turn‐on and imaging of endogenous PHGDH activity.…”

Construction of α‐(Hetero)aryl Ethenesulfonyl Fluorides for SuFEx Click Chemistry

“…[6d], On the other hand, the terminal vinyl sulfonyl compounds have been recognized as a significant covalent‐bonds‐formation tool in bioconjugation of proteins, polymers, carbohydrates type of biomolecules, fluorescent,[11a], electrochemically active[11a], or affinity‐binding tags. [11a], In addition, the terminal vinyl sulfone‐based fluorogenic probes (Figure , I and II ) have recently been developed as potential covalent pharmacophores for selectively labeling in living cells. Additionally, terminal olefins are prevalent in natural products, (Figure ) such as acremonide ( III ), and ruguloxanthones C ( IV ) .…”