Discovery of a CK2α'-Biased ATP-Competitive Inhibitor from a High-Throughput Screen of an Allosteric-Inhibitor-Like Compound Library.

Protein kinase CK2 is a holoenzyme composed of two regulatory subunits (CK2β) and two catalytic subunits (CK2α and CK2α'). CK2 controls several cellular processes, including proliferation, inflammation, and cell death. However, CK2α and CK2α' possess different expression patterns and substrates and therefore impact each of these processes differently.

Development of Allosteric Small Molecule APOBEC3B Inhibitors from Screening.

APOBEC3B cytosine deaminase contributes to the mutational burdens of tumors, resulting in tumor progression and therapy resistance. Small molecule APOBEC3B inhibitors have potential to slow or mitigate these detrimental outcomes. Through molecular dynamics (MD) simulations and computational solvent mapping analysis, we identified a novel putative allosteric pocket on the C-terminal domain of APOBEC3B (A3Bctd), and virtually screened the ChemBridge Diversity Set (N~110,000) against both the active and potential allosteric sites.

Identification of CK2α' selective inhibitors by the screening of an allosteric-kinase-inhibitor-like compound library.

Protein Kinase CK2 is a holoenzyme composed of two regulatory subunits (CK2β) and two catalytic subunits (CK2α and CK2α'). CK2 controls several cellular processes including proliferation, inflammation, and cell death. However, CK2α and CK2α' possess different expression patterns and substrates and therefore impact each of these processes differently.

An electrophilic fragment screening for the development of small molecules targeting caspase-2.

Recent Alzheimer's research has shown increasing interest in the caspase-2 (Casp2) enzyme. However, the available Casp2 inhibitors, which have been pentapeptides or peptidomimetics, face challenges for use as CNS drugs. In this study, we successfully screened a 1920-compound chloroacetamide-based, electrophilic fragment library from Enamine.

Reference compounds for characterizing cellular injury in high-content cellular morphology assays.

Robust, generalizable approaches to identify compounds efficiently with undesirable mechanisms of action in complex cellular assays remain elusive. Such a process would be useful for hit triage during high-throughput screening and, ultimately, predictive toxicology during drug development. Here we generate cell painting and cellular health profiles for 218 prototypical cytotoxic and nuisance compounds in U-2 OS cells in a concentration-response format.

Targeting caspase-2 interactions with tau in Alzheimer's disease and related dementias.

Targeting amyloid-β plaques and tau tangles has failed to provide effective treatments for Alzheimer's disease and related dementias (ADRD). A more fruitful pathway to ADRD therapeutics may be the development of therapies that target common signaling pathways that disrupt synaptic connections and impede communication between neurons. In this review, we present our characterization of a signaling pathway common to several neurological diseases featuring dementia including Alzheimer's disease, frontotemporal dementia, Lewy body dementia, and Huntington's disease.

Threonine Cavities Are Targetable Motifs That Control Alpha-Synuclein Fibril Growth.

Recent high-resolution structures of alpha-synuclein (aSyn) fibrils offer promise for rational approaches to drug discovery for Parkinson's disease and Lewy body dementia. Harnessing the first such structures, we previously used molecular dynamics and free energy calculations to suggest that threonines 72 and 75─which line water-filled cavities within the fibril stacks─may be of central importance in stabilizing fibrils. Here, we used experimental mutagenesis of both wild-type and A53T aSyn to show that both threonine residues play important but surprisingly disparate roles in fibril nucleation and elongation.

Characterization of caspase-2 inhibitors based on specific sites of caspase-2-mediated proteolysis.

Since the discovery of the caspase-2 (Casp2)-mediated ∆tau314 cleavage product and its associated impact on tauopathies such as Alzheimer's disease, the design of selective Casp2 inhibitors has become a focus in medicinal chemistry research. In the search for new lead structures with respect to Casp2 selectivity and drug-likeness, we have taken an approach by looking more closely at the specific sites of Casp2-mediated proteolysis. Using seven selected protein cleavage sequences, we synthesized a peptide series of 53 novel molecules and studied them using in vitro pharmacology, molecular modeling, and crystallography.

Caspase-2 Inhibitor Blocks Tau Truncation and Restores Excitatory Neurotransmission in Neurons Modeling FTDP-17 Tauopathy.

Synaptic and cognitive deficits mediated by a severe reduction in excitatory neurotransmission caused by a disproportionate accumulation of the neuronal protein tau in dendritic spines is a fundamental mechanism that has been found repeatedly in models of tauopathies, including Alzheimer's disease, Lewy body dementia, frontotemporal dementia, and traumatic brain injury. Synapses thus damaged may contribute to dementia, among the most feared cause of debilitation in the elderly, and currently there are no treatments to repair them. Caspase-2 (Casp2) is an essential component of this pathological cascade.

Structure-Based Design and Biological Evaluation of Novel Caspase-2 Inhibitors Based on the Peptide AcVDVAD-CHO and the Caspase-2-Mediated Tau Cleavage Sequence YKPVD314.

Alzheimer's disease (AD) was first described by Alois Alzheimer over 100 years ago, but there is still no overarching theory that can explain its cause in detail. There are also no effective therapies to treat either the cause or the associated symptoms of this devastating disease. A potential approach to better understand the pathogenesis of AD could be the development of selective caspase-2 (Casp2) probes, as we have shown that a Casp2-mediated cleavage product of tau (Δtau314) reversibly impairs cognitive and synaptic function in animal models of tauopathies.

Remodelin Is a Cryptic Assay Interference Chemotype That Does Not Inhibit NAT10-Dependent Cytidine Acetylation.

Remodelin is a putative small molecule inhibitor of the RNA acetyltransferase NAT10 which has shown preclinical efficacy in models of the premature aging disease Hutchinson-Gilford Progeria Syndrome (HGPS). Here we evaluate remodelin's assay interference characteristics and effects on NAT10-catalyzed RNA cytidine acetylation. We find the remodelin chemotype constitutes a cryptic assay interference compound, which does not react with small molecule thiols but demonstrates protein reactivity in ALARM NMR and proteome-wide affinity profiling assays.

The Communication of Hit Quality Using Natural History Visualizations (NHVs).

High-throughput screening (HTS) often yields a list of compounds that requires prioritization before further work is performed. Prioritization criteria typically include activity, selectivity, physicochemical properties, and other absolute or calculated measurements of compound "value." One critical method of compound prioritization is often not discussed in published accounts of HTS.

Nuisance compounds in cellular assays.

Compounds that exhibit assay interference or undesirable mechanisms of bioactivity ("nuisance compounds") are routinely encountered in cellular assays, including phenotypic and high-content screening assays. Much is known regarding compound-dependent assay interferences in cell-free assays. However, despite the essential role of cellular assays in chemical biology and drug discovery, there is considerably less known about nuisance compounds in more complex cell-based assays.

Synthesis of Guaianolide Analogues with a Tunable α-Methylene-γ-lactam Electrophile and Correlating Bioactivity with Thiol Reactivity.

α-Methylene-γ-lactones are present in ∼3% of known natural products, and compounds comprising this motif display a range of biological activities. However, this reactive lactone limits informed structure-activity relationships for these bioactive molecules. Herein, we describe chemically tuning the electrophilicity of the α-methylene-γ-lactone by replacement with an α-methylene-γ-lactam.

The Essential Medicinal Chemistry of Cannabidiol (CBD).

This Perspective of the published essential medicinal chemistry of cannabidiol (CBD) provides evidence that the popularization of CBD-fortified or CBD-labeled health products and CBD-associated health claims lacks a rigorous scientific foundation. CBD's reputation as a cure-all puts it in the same class as other "natural" panaceas, where valid ethnobotanicals are reduced to single, purportedly active ingredients. Such reductionist approaches oversimplify useful, chemically complex mixtures in an attempt to rationalize the commercial utility of natural compounds and exploit the "natural" label.

Development of Benzenesulfonamide Derivatives as Potent Glutathione Transferase Omega-1 Inhibitors.

Glutathione transferase omega-1 (GSTO1-1) is an enzyme whose function supports the activation of interleukin (IL)-1β and IL-18 that are implicated in a variety of inflammatory disease states for which small-molecule inhibitors are sought. The potent reactivity of the active-site cysteine has resulted in reported inhibitors that act by covalent labeling. In this study, structure-activity relationship (SAR) elaboration of the reported GSTO1-1 inhibitor was undertaken.

Anastrozole has an Association between Degree of Estrogen Suppression and Outcomes in Early Breast Cancer and is a Ligand for Estrogen Receptor α.

Purpose: To determine if the degree of estrogen suppression with aromatase inhibitors (AI: anastrozole, exemestane, letrozole) is associated with efficacy in early-stage breast cancer, and to examine for differences in the mechanism of action between the three AIs.

Experimental Design: Matched case-control studies [247 matched sets from MA.27 (anastrozole vs.

Diversity-Oriented Library Synthesis from Steviol and Isosteviol-Derived Scaffolds.

The readily available natural product stevioside provides a unique diterpene core structure that can be explored for small molecule library development by diversity-oriented synthesis and functional group transformations. Validation arrays were prepared from steviol, isosteviol, and related analogues, derived from stevioside, to produce over 90 compounds. These compounds were submitted to the NIH Molecular Libraries Small Molecule Repository for screening in the Molecular Libraries Screening Center Network.

Improving natural product research translation: From source to clinical trial.

While great interest in health effects of natural product (NP) including dietary supplements and foods persists, promising preclinical NP research is not consistently translating into actionable clinical trial (CT) outcomes. Generally considered the gold standard for assessing safety and efficacy, CTs, especially phase III CTs, are costly and require rigorous planning to optimize the value of the information obtained. More effective bridging from NP research to CT was the goal of a September, 2018 transdisciplinary workshop.

Author Correction: Cytotoxic unsaturated electrophilic compounds commonly target the ubiquitin proteasome system.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A novel P300 inhibitor reverses DUX4-mediated global histone H3 hyperacetylation, target gene expression, and cell death.

Facioscapulohumeral muscular dystrophy (FSHD) results from mutations causing overexpression of the transcription factor, DUX4, which interacts with the histone acetyltransferases, EP300 and CBP. We describe the activity of a new spirocyclic EP300/CBP inhibitor, iP300w, which inhibits the cytotoxicity of the DUX4 protein and reverses the overexpression of most DUX4 target genes, in engineered cell lines and FSHD myoblasts, as well as in an FSHD animal model. In evaluating the effect of iP300w on global histone H3 acetylation, we discovered that DUX4 overexpression leads to a dramatic global increase in the total amount of acetylated histone H3.

Cytotoxic unsaturated electrophilic compounds commonly target the ubiquitin proteasome system.

A large number of natural products have been advocated as anticancer agents. Many of these compounds contain functional groups characterized by chemical reactivity. It is not clear whether distinct mechanisms of action can be attributed to such compounds.

Discovery of Benzoylsulfonohydrazides as Potent Inhibitors of the Histone Acetyltransferase KAT6A.

A high-throughput screen for inhibitors of the histone acetyltransferase, KAT6A, led to identification of an aryl sulfonohydrazide derivative (CTX-0124143) that inhibited KAT6A with an IC of 1.0 μM. Elaboration of the structure-activity relationship and medicinal chemistry optimization led to the discovery of WM-8014 (), a highly potent inhibitor of KAT6A (IC = 0.

3,3'-Disubstituted 5,5'-Bi(1,2,4-triazine) Derivatives with Potent in Vitro and in Vivo Antimalarial Activity.

A series of 3,3'-disubstituted 5,5'-bi(1,2,4-triazine) derivatives was synthesized and screened against the erythrocytic stage of Plasmodium falciparum 3D7 line. The most potent dimer, 6k, with an IC (50% inhibitory concentration) of 0.008 μM, had high in vitro potency against P.