Inhibitors of Cyclic Mononucleotide and Cyclic Dinucleotide Phosphodiesterases

Purdue University researchers have identified a cyclic dinucleotide phosphodiesterase inhibitor for future development as an agent to combat Mycobacterium tuberculosis (MTB). Bacterial and viral phosphodiesterases contribute to infection by preventing the host from mounting a full immune response. The Purdue researchers employed a high throughput screening assay to identify inhibitors of MTB c-di-AMP phosphodiesterase (CdnP). The researchers selected compounds that displayed greater than 40 percent inhibition in a fluorescence-based assay of MTB CdnP activity. They then identified the most potent of the MTB CdnP inhibitors in enzymatic assays monitored by HPLC and comparative radioisotope thin layer chromatography. The researchers used MTB CdnP intrinsic fluorescence to further confirm that the identified compound binds directly to MTB CdnP. The researchers also confirmed that the inhibitor is specific to MTB CdnP; it did not inhibit any other enzymes in a panel of bacterial, mammalian, and viral phosphodiesterases. The compound further shows promise as an antibiotic because it does not affect mammalian cell viability at concentrations up to 100 micromolar.

Advantages:

-Effective

-Specific

-Nontoxic

Potential Applications:

-Antivirulence drugs

-Antibiotics

-Anti-inflammatory drugs

-Cancer immunotherapy

Technology Validation:

The researchers tested over 90,000 compounds for cyclic dinucleotide phosphodiesterase (CdnP) inhibition capability using high-throughput screening (HTS) with the group's Coralyne assay; over 40% of the drugs had inhibitory capability. They then confirmed the inhibitory effects of these compounds using chromatography. The researchers used the HTS and chromatography data to identify the most effective CdnP inhibitor. They were then able to determine the mechanism by which this compounds inhibits CdnP.

Related Publication:

Identification of a Mycobacterium tuberculosis Cyclic Dinucleotide Phosphodiesterase Inhibitor

ACS Infect. Dis. 2021, 7, 309−317

https://dx.doi.org/10.1021/acsinfecdis.0c00444

TRL: 3

Intellectual Property:

Keywords: cyclic dinucleotide phosphodiesterase inhibitor, Mycobacterium tuberculosis, MTB c-di-AMP phosphodiesterase, CdnP inhibitor, anti-virulence drug, antibiotic, anti-inflammatory drug, cancer immunotherapy, high-throughput screening, HTS, Coralyne assay, nontoxic inhibitor