scholarly journals Development of potent small-molecule inhibitors to drug the undruggable steroid receptor coactivator-3

2016 ◽  
Vol 113 (18) ◽  
pp. 4970-4975 ◽  
Author(s):  
Xianzhou Song ◽  
Jianwei Chen ◽  
Mingkun Zhao ◽  
Chengwei Zhang ◽  
Yang Yu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Small Molecule ◽  
Protein Interactions ◽  
High Throughput Screening ◽  
Small Molecule Inhibitors ◽  
Structural Information ◽  
Steroid Receptor ◽  
Functional Assay ◽  
Lipinski’S Rule ◽  
Steroid Receptor Coactivator

Protein–protein interactions (PPIs) play a central role in most biological processes, and therefore represent an important class of targets for therapeutic development. However, disrupting PPIs using small-molecule inhibitors (SMIs) is challenging and often deemed as “undruggable.” We developed a cell-based functional assay for high-throughput screening to identify SMIs for steroid receptor coactivator-3 (SRC-3 or AIB1), a large and mostly unstructured nuclear protein. Without any SRC-3 structural information, we identified SI-2 as a highly promising SMI for SRC-3. SI-2 meets all of the criteria of Lipinski’s rule [Lipinski et al. (2001) Adv Drug Deliv Rev 46(1-3):3–26] for a drug-like molecule and has a half-life of 1 h in a pharmacokinetics study and a reasonable oral availability in mice. As a SRC-3 SMI, SI-2 can selectively reduce the transcriptional activities and the protein concentrations of SRC-3 in cells through direct physical interactions with SRC-3, and selectively induce breast cancer cell death with IC50 values in the low nanomolar range (3–20 nM), but not affect normal cell viability. Furthermore, SI-2 can significantly inhibit primary tumor growth and reduce SRC-3 protein levels in a breast cancer mouse model. In a toxicology study, SI-2 caused minimal acute cardiotoxicity based on a hERG channel blocking assay and an unappreciable chronic toxicity to major organs based on histological analyses. We believe that this work could significantly improve breast cancer treatment through the development of “first-in-class” drugs that target oncogenic coactivators.

scholarly journals A Time-Resolved Fluorescence Assay to Identify Small-Molecule Inhibitors of HIV-1 Fusion

2007 ◽  
Vol 12 (6) ◽  
pp. 865-874 ◽  
Author(s):  
Géry Dams ◽  
Koen Van Acker ◽  
Emmanuel Gustin ◽  
Inge Vereycken ◽  
Lieve Bunkens ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Protein Interactions ◽  
High Throughput Screening ◽  
Small Molecule Inhibitors ◽  
Coiled Coil ◽  
Heptad Repeat ◽  
Time Resolved ◽  
Helix Bundle ◽  
Hiv 1

Fusion of host cell and human immunodeficiency virus type 1 (HIV-1) membranes is mediated by the 2 “heptad-repeat” regions of the viral gp41 protein. The collapse of the C-terminal heptad-repeat regions into the hydrophobic grooves of a coiled-coil formed by the corresponding homotrimeric N-terminal heptad-repeat regions generates a stable 6-helix bundle. This brings viral and cell membranes together for membrane fusion, facilitating viral entry. The authors developed an assay based on soluble peptides derived from the gp41 N-terminal heptad-repeat region (IQN36) as well as from the C-terminal region (C34). Both peptides were labeled with fluorophores, IQN36 with allophycocyanin (APC) and C34 with the lanthanide europium (Eu3+). Formation of the 6-helix bundle brings both fluorophores in close proximity needed for Förster resonance energy transfer (FRET). Compounds that interfere with binding of C34-Eu with IQN36-APC suppress the FRET signal. The assay was validated with various peptides and small molecules, and quenching issues were addressed. Evaluation of a diversified compound collection in a high-throughput screening campaign enabled identification of small molecules with different chemical scaffolds that inhibit this crucial intermediate in the HIV-1 entry process. This study's observations substantiate the expediency of time-resolved FRET-based assays to identify small-molecule inhibitors of protein-protein interactions. ( Journal of Biomolecular Screening 2007:865-874)

scholarly journals A High-Throughput Screening Strategy to Identify Inhibitors of SSB Protein–Protein Interactions in an Academic Screening Facility

2017 ◽  
Vol 23 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Andrew F. Voter ◽  
Michael P. Killoran ◽  
Gene E. Ananiev ◽  
Scott A. Wildman ◽  
F. Michael Hoffmann ◽  
...  
Keyword(s):  
Small Molecule ◽  
High Throughput ◽  
Protein Interactions ◽  
High Throughput Screening ◽  
Bacterial Infections ◽  
Small Molecule Inhibitors ◽  
Klebsiella Pneumonia ◽  
Protein Protein Interactions ◽  
Response Curves ◽  
Single Stranded Dna

Antibiotic-resistant bacterial infections are increasingly prevalent worldwide, and there is an urgent need for novel classes of antibiotics capable of overcoming existing resistance mechanisms. One potential antibiotic target is the bacterial single-stranded DNA binding protein (SSB), which serves as a hub for DNA repair, recombination, and replication. Eight highly conserved residues at the C-terminus of SSB use direct protein–protein interactions (PPIs) to recruit more than a dozen important genome maintenance proteins to single-stranded DNA. Mutations that disrupt PPIs with the C-terminal tail of SSB are lethal, suggesting that small-molecule inhibitors of these critical SSB PPIs could be effective antibacterial agents. As a first step toward implementing this strategy, we have developed orthogonal high-throughput screening assays to identify small-molecule inhibitors of the Klebsiella pneumonia SSB-PriA interaction. Hits were identified from an initial screen of 72,474 compounds using an AlphaScreen (AS) primary screen, and their activity was subsequently confirmed in an orthogonal fluorescence polarization (FP) assay. As an additional control, an FP assay targeted against an unrelated eukaryotic PPI was used to confirm specificity for the SSB-PriA interaction. Nine potent and selective inhibitors produced concentration–response curves with IC50 values of <40 μM, and two compounds were observed to directly bind to PriA, demonstrating the success of this screen strategy.

Identification of small-molecule inhibitors of the JIP–JNK interaction

2009 ◽  
Vol 420 (2) ◽  
pp. 283-296 ◽  
Author(s):  
Tracy Chen ◽  
Natasha Kablaoui ◽  
Jeremy Little ◽  
Sergei Timofeevski ◽  
William R. Tschantz ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Small Molecule ◽  
Protein Interactions ◽  
High Throughput Screening ◽  
Small Molecule Inhibitors ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Protein ◽  
Fluorescence Polarization Assay

JNK1 (c-Jun N-terminal kinase 1) plays a crucial role in the regulation of obesity-induced insulin resistance and is implicated in the pathology of Type 2 diabetes. Its partner, JIP1 (JNK-interacting protein 1), serves a scaffolding function that facilitates JNK1 activation by MKK4 [MAPK (mitogen-activated protein kinase) kinase 4] and MKK7 (MAPK kinase 7). For example, reduced insulin resistance and JNK activation are observed in JIP1-deficient mice. On the basis of the in vivo efficacy of a cell-permeable JIP peptide, the JIP–JNK interaction appears to be a potential target for JNK inhibition. The goal of the present study was to identify small-molecule inhibitors that disrupt the JIP–JNK interaction to provide an alternative approach for JNK inhibition to ATP-competitive inhibitors. High-throughput screening was performed by utilizing a fluorescence polarization assay that measured the binding of JNK1 to the JIP peptide. Multiple chemical series were identified, revealing two categories of JIP/JNK inhibitors: ‘dual inhibitors’ that are ATP competitive and probably inhibit JIP–JNK binding allosterically, and ‘JIP-site binders’ that block binding through interaction with the JIP site. A series of polychloropyrimidines from the second category was characterized by biochemical methods and explored through medicinal-chemistry efforts. As predicted, these inhibitors also inhibited full-length JIP–JNK binding and were selective against a panel of 34 representative kinases, including ones in the MAPK family. Overall, this work demonstrates that small molecules can inhibit protein–protein interactions in vitro in the MAPK family effectively and provides strategies for similar approaches within other target families.

scholarly journals Identification of novel small molecule inhibitors of adenovirus gene transfer using a high throughput screening approach

2013 ◽  
Vol 170 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Margaret R. Duffy ◽  
Alan L. Parker ◽  
Eric R. Kalkman ◽  
Katie White ◽  
Dmytro Kovalskyy ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Small Molecule ◽  
High Throughput ◽  
High Throughput Screening ◽  
Small Molecule Inhibitors ◽  
Screening Approach

scholarly journals High throughput screening for small molecule inhibitors of heparin-induced tau fibril formation

2007 ◽  
Vol 358 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Alex Crowe ◽  
Carlo Ballatore ◽  
Edward Hyde ◽  
John Q. Trojanowski ◽  
Virginia M.-Y. Lee
Keyword(s):  
Small Molecule ◽  
High Throughput ◽  
High Throughput Screening ◽  
Small Molecule Inhibitors ◽  
Fibril Formation
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