2‑Bromopalmitate Analogues as Activity-Based Probes To Explore Palmitoyl Acyltransferases

Reversible S-palmitoylation
is an important post-translational
modification that regulates the trafficking, localization, and activity
of proteins. Cysteine-rich Asp-His-His-Cys (DHHC) domain-containing
enzymes are evolutionarily conserved protein palmitoyl acyltransferases
(PATs). The human genome encodes 23 DHHC-PATs that regulate diverse
cellular functions. Although chemical probes and proteomic methods
to detect palmitoylated protein substrates have been reported, no
probes for direct detection of the activity of PATs are available.
Here we report the synthesis and characterization of 2-bromohexadec-15-ynoic
acid and 2-bromooctadec-17-ynoic acid, which are analogues of 2-bromopalmitate
(2-BP), as activity-based probes for PATs as well as other palmitoylating
and 2-BP-binding enzymes. These probes will serve as new chemical
tools for activity-based protein profiling to explore PATs, to dissect
the functions of PATs in cell signaling and diseases, and to facilitate
the identification of their inhibitors.