1 research outputs found
Identification of New Modulators and Inhibitors of Palmitoyl-Protein Thioesterase 1 for CLN1 Batten Disease and Cancer
Palmitoyl-protein
thioesterase 1 (PPT1) is an understudied
enzyme
that is gaining attention due to its role in the depalmitoylation
of several proteins involved in neurodegenerative diseases and cancer.
PPT1 is overexpressed in several cancers, specifically cholangiocarcinoma
and esophageal cancers. Inhibitors of PPT1 lead to cell death and
have been shown to enhance the killing of tumor cells alongside known
chemotherapeutics. PPT1 is hence a viable target for anticancer drug
development. Furthermore, mutations in PPT1 cause a lysosomal storage
disorder called infantile neuronal ceroid lipofuscinosis (CLN1 disease).
Molecules that can inhibit, stabilize, or modulate the activity of
this target are needed to address these diseases. We used PPT1 enzymatic
assays to identify molecules that were subsequently tested by using
differential scanning fluorimetry and microscale thermophoresis. Selected
compounds were also tested in neuroblastoma cell lines. The resulting
PPT1 screening data was used for building machine learning models
to help select additional compounds for testing. We discovered two
of the most potent PPT1 inhibitors reported to date, orlistat (IC50 178.8 nM) and palmostatin B (IC50 11.8 nM). When
tested in HepG2 cells, it was found that these molecules had decreased
activity, indicating that they were likely not penetrating the cells.
The combination of in vitro enzymatic and biophysical assays enabled
the identification of several molecules that can bind or inhibit PPT1
and may aid in the discovery of modulators or chaperones. The molecules
identified could be used as a starting point for further optimization
as treatments for other potential therapeutic applications outside
CLN1 disease, such as cancer and neurological diseases