SH2scan: Mapping SH2 Domain-Ligand Binding Selectivity for Inhibitors and Degraders
https://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.5c02392
Abstract:
Drug discovery targeting SH2 domains (key protein–protein interaction modules) has been hampered by a lack of assay systems evaluating synthetic ligand binding selectivity toward SH2 domains to reduce potential off-target effects. In addition, the molecular determinants for the synthetic ligand engagement to SH2 domains across the target class have yet to be defined. Here, we developed SH2scan, a high-throughput competition binding assay platform to quantify ligand-SH2 domain interactions, covering >80% of the target class. We uncovered unique binding selectivity profiles and quantified a broad range of dissociation constants (KDs) for 9 synthetic ligands of SH2 domains from the scientific literature with a range of reported primary targets. These results demonstrate that SH2scan can be used to design more selective compounds targeting the SH2 domains. The platform can be further leveraged for the discovery of new molecular probes for the dissection of cellular protein–protein interaction networks.
Discovery of a Highly Potent and Selective Small-Molecule Inhibitor of In Vivo Anaerobic Choline Metabolism by Human Gut Bacteria
https://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.5c01451
Abstract:
Trimethylamine (TMA) Lyase is an enzyme expressed in human gut bacteria that plays a pivotal role in the formation of trimethylamine oxide (TMAO), a metabolite implicated in the development of heart failure. Here, we describe a strategy to design covalent inhibitors targeting the active site thiyl radical involved in the catalytic cycle of the enzyme under anaerobic conditions. This strategy led to the discovery of 7, a previously unreported highly potent and selective inhibitor of TMA Lyase. When dosed orally to rats, 7 shows a significant reduction of circulating TMAO levels and, importantly, demonstrates inhibition of TMAO generated from a human microbiome when profiled in a human fecal mouse transplant model.
Discovery of EGT710, an Oral Nonpeptidomimetic Reversible Covalent SARS-CoV-2 Main Protease Inhibitor
https://pubs.acs.org/doi/full/10.1021/acs.jmedchem.5c02360
Abstract:
The coronavirus main protease (3CLpro, Mpro, nsp5) is a highly conserved cysteine protease unique to the Coronaviridae family, including SARS-CoV-2, and is a validated target for the treatment of COVID-19. Our efforts focused on the identification of a nonpeptidomimetic Mpro inhibitor, due to the potential for superior pharmacological properties. Herein, we report our efforts leveraging virtual screening and X-ray crystallography that enabled a structure-based drug design approach, leading to the discovery of series of quinazoline-2,4(1H,3H)-dione and oxoimidazolidine-4-carbonitrile compounds with potent inhibition of SARS-CoV-2 Mpro as well as other coronaviruses main proteases. Extensive lead optimization focusing on pharmacokinetic properties, developability, and breadth of activity across coronaviruses, led to the identification of EGT710. EGT710 demonstrates excellent potency against SARS-CoV-2 infection in a primary differentiated normal human bronchial epithelial (dNHBE) cellular assay, as well as a favorable pharmacology profile that supported advancement into preclinical and clinical studies.
Orally Bioavailable Cyclin A/B RxL Inhibitors: Optimization of a Novel Class of Macrocyclic Peptides That Target E2F-High and G1–S-Checkpoint-Compromised Cancers
https://pubs.acs.org/doi/full/10.1021/acs.jmedchem.5c02445
Abstract:
Cyclins A and B bind and activate their cognate cyclin-dependent kinase (CDK) to regulate progression through the S and G2/M phases of the cell cycle, respectively. Cyclins recruit substrates and regulators through the binding of an RxL motif with a Hydrophobic Patch (HP) on the cyclin surface. We recently disclosed the first class of passively permeable macrocyclic peptides that bind to the HP of both Cyclin A and Cyclin B and selectively kill cancer cells with high E2F activity. We used a lead example to demonstrate in vivo tumor regression in cell-line-derived xenograft models of small-cell lung cancer (SCLC) via intraperitoneal dosing. Here we describe the optimization of this series for drug-like properties and oral bioavailability, resulting in the discovery of a lead compound, which demonstrates tumor regression in CDX models of SCLC via oral dosing. We are currently evaluating Cyclin A/B inhibition in a Phase 1 clinical trial.
