Click. Screen. Degrade. A Miniaturized D2B Workflow for Rapid PROTAC Discovery

Targeted protein degradation is one of the fastest developing
fields
in medicinal chemistry and chemical biology. Despite significant development
in assay technologies and inhibitor discovery, the development of
PROTACs remains a challenging endeavor since rational design approaches
remain widely elusive. Our workflow eliminates the rate-limiting step
of classic synthesis, namely compound purification, and pairs it with
high-throughput, semi-automated plate-based synthesis, and direct
cellular assay evaluation. We applied this direct-to-biology approach
to four diverse targets, demonstrating the general applicability of
this technology. PROTAC synthesis was realized by using the highly
efficient copper-catalyzed azide–alkyne cycloaddition reaction.
This simplified reaction setup enabled synthesis in the nanomole scale
with reaction volumes as low as 5 μL. The high-throughput strategy
allows hundreds of PROTACs to be synthesized and evaluated within
a few days, facilitating comprehensive assessment of target degradability,
rapid hit identification, and selection of the most suitable E3 ligase
for degrader development.