A novel micellular fluorogenic substrate for quantitating the activity of 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma (PLCγ) enzymes.

The activities of the phospholipase C gamma (PLCγ) 1 and 2 enzymes are essential for numerous cellular processes. Unsurprisingly, dysregulation of PLCγ1 or PLCγ2 activity is associated with multiple maladies including immune disorders, cancers, and neurodegenerative diseases. Therefore, the modulation of either of these two enzymes has been suggested as a therapeutic strategy to combat these diseases.

Exploration of P1 and P4 modifications of nirmatrelvir: Design, synthesis, biological evaluation, and X-ray structural studies of SARS-CoV-2 Mpro inhibitors.

We report the synthesis, biological evaluation, and X-ray structural studies of a series of SARS-CoV-2 Mpro inhibitors based upon the X-ray crystal structure of nirmatrelvir, an FDA approved drug that targets the main protease of SARS-CoV-2. The studies involved examination of various P4 moieties, P1 five- and six-membered lactam rings to improve potency. In particular, the six-membered P1 lactam ring analogs exhibited high SARS-CoV-2 Mpro inhibitory activity.

Development of a sensitive microplate assay for characterizing RNA methyltransferase activity: Implications for epitranscriptomics and drug development.

RNA methylation is a ubiquitous post-transcriptional modification found in diverse RNA classes and is a critical regulator of gene expression. In this study, we used Zika virus RNA methyltransferase (MTase) to develop a highly sensitive microplate assay that uses a biotinylated RNA substrate and radiolabeled AdoMet coenzyme. The assay is fast, highly reproducible, exhibits linear progress-curve kinetics under multiple turnover conditions, has high sensitivity in competitive inhibition assays, and significantly lower background levels compared with the currently used method.

A novel fluorogenic reporter substrate for 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-2 (PLCγ2): Application to high-throughput screening for activators to treat Alzheimer's disease.

A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified.

Preclinical characterization of an intravenous coronavirus 3CL protease inhibitor for the potential treatment of COVID19.

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. PF-00835231, a 3CL protease inhibitor, has exhibited potent in vitro antiviral activity against SARS-CoV-2 as a single agent.

Chloropyridinyl Esters of Nonsteroidal Anti-Inflammatory Agents and Related Derivatives as Potent SARS-CoV-2 3CL Protease Inhibitors.

We report the design and synthesis of a series of new 5-chloropyridinyl esters of salicylic acid, ibuprofen, indomethacin, and related aromatic carboxylic acids for evaluation against SARS-CoV-2 3CL protease enzyme. These ester derivatives were synthesized using EDC in the presence of DMAP to provide various esters in good to excellent yields. Compounds are stable and purified by silica gel chromatography and characterized using H-NMR, C-NMR, and mass spectral analysis.

Indole Chloropyridinyl Ester-Derived SARS-CoV-2 3CLpro Inhibitors: Enzyme Inhibition, Antiviral Efficacy, Structure-Activity Relationship, and X-ray Structural Studies.

Here, we report the synthesis, structure-activity relationship studies, enzyme inhibition, antiviral activity, and X-ray crystallographic studies of 5-chloropyridinyl indole carboxylate derivatives as a potent class of SARS-CoV-2 chymotrypsin-like protease inhibitors. Compound exhibited a SARS-CoV-2 3CLpro inhibitory IC value of 250 nM and an antiviral EC value of 2.8 μM in VeroE6 cells.

A small molecule compound with an indole moiety inhibits the main protease of SARS-CoV-2 and blocks virus replication.

Except remdesivir, no specific antivirals for SARS-CoV-2 infection are currently available. Here, we characterize two small-molecule-compounds, named GRL-1720 and 5h, containing an indoline and indole moiety, respectively, which target the SARS-CoV-2 main protease (M). We use VeroE6 cell-based assays with RNA-qPCR, cytopathic assays, and immunocytochemistry and show both compounds to block the infectivity of SARS-CoV-2 with EC values of 15 ± 4 and 4.

Discovery of a Novel Inhibitor of Coronavirus 3CL Protease for the Potential Treatment of COVID-19.

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. The designed phosphate prodrug PF-07304814 is metabolized to PF-00835321 which is a potent inhibitor of the coronavirus family 3CL pro, with selectivity over human host protease targets.

Highly Selective and Potent Human β-Secretase 2 (BACE2) Inhibitors against Type 2 Diabetes: Design, Synthesis, X-ray Structure and Structure-Activity Relationship Studies.

Herein we present the design, synthesis, and biological evaluation of potent and highly selective β-secretase 2 (memapsin 1, beta-site amyloid precursor protein cleaving enzyme 2, or BACE 2) inhibitors. BACE2 has been recognized as an exciting new target for type 2 diabetes. The X-ray structure of BACE1 bound to inhibitor 2 a {N -[(1S,2R)-1-benzyl-2-hydroxy-3-[[(1S,2S)-2-hydroxy-1-(isobutylcarbamoyl)propyl]amino]propyl]-5-[methyl(methylsulfonyl)amino]-N -[(1R)-1-phenylpropyl]benzene-1,3-dicarboxamide} containing a hydroxyethylamine isostere was determined.

Design, synthesis, X-ray studies, and biological evaluation of novel BACE1 inhibitors with bicyclic isoxazoline carboxamides as the P3 ligand.

We describe the design, synthesis, X-ray studies, and biological evaluation of novel BACE1 inhibitors containing bicyclic isoxazoline carboxamides as the P3 ligand in combination with methyl cysteine, methylsulfonylalanine and Boc-amino alanine as P2 ligands. Inhibitor 3a displayed a BACE1 K value of 10.9 nM and EC of 343 nM.

Two Divalent Metal Ions and Conformational Changes Play Roles in the Hammerhead Ribozyme Cleavage Reaction.

The hammerhead ribozyme is a self-cleaving RNA broadly dispersed across all kingdoms of life. Although it was the first of the small, nucleolytic ribozymes discovered, the mechanism by which it catalyzes its reaction remains elusive. The nucleobase of G12 is well positioned to be a general base, but it is unclear if or how this guanine base becomes activated for proton transfer.