Development and Characterization of a Fluorescent Probe for GLS1 and the Application for High-Throughput Screening of Allosteric Inhibitors

Glutaminase
(GLS1) is a cancer energy metabolism protein which
plays a predominant role in cell growth and proliferation. Because
of its major involvement in malignant tumor, small-molecule GLS1 inhibitors
are urgently needed to assess its therapeutic potential and for probing
their underlying biology function. Recent studies showed that targeting
the allosteric binding site represented a promising strategy for identifying
potent and selective GLS1 inhibitors. Herein, we present the synthesis
of two fluorescent probes targeting the allosteric binding site of
GLS1 and their usage as mechanistic tools in multiple applicable assay
platform. The fluorescence polarization (FP)-based binding assay enables
easy, fast, and reliable screen of allosteric inhibitors from our
in-house compound library obtained through click chemistry method.
The obtained compound C147 (named as CPU-L1) has been proved to be more potent and with greater
solubility than the control compound CB839, which could
serve as promising leads for further optimization as novel GLS1 inhibitors.