scholarly journals Identification and validation of novel and more effective choline kinase inhibitors against Streptococcus pneumoniae

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tahl Zimmerman ◽  
Valerie Chasten ◽  
Juan Carlos Lacal ◽  
Salam A. Ibrahim
Keyword(s):  
Streptococcus Pneumoniae ◽  
Drug Target ◽  
Kinase Inhibitors ◽  
Teichoic Acid ◽  
Cellular Level ◽  
Choline Kinase ◽  
Potential Therapeutic Target ◽  
Enzymatic Assays ◽  
Induced Autolysis ◽  
Promising Avenue

Abstract Streptococcus pneumoniae choline kinase (sChoK) has previously been proposed as a drug target, yet the effectiveness of the first and only known inhibitor of sChoK, HC-3, is in the millimolar range. The aim of this study was thus to further validate sChoK as a potential therapeutic target by discovering more powerful sChoK inhibitors. LDH/PK and colorimetric enzymatic assays revealed two promising sChoK inhibitor leads RSM-932A and MN58b that were discovered with IC50 of 0.5 and 150 μM, respectively, and were shown to be 2–4 magnitudes more potent than the previously discovered inhibitor HC-3. Culture assays showed that the minimum inhibitory concentration (MIC) of RSM-932A and MN58b for S. pneumoniae was 0.4 μM and 10 μM, respectively, and the minimum lethal concentration (MLC) was 1.6 μM and 20 μM, respectively. Western blot monitoring of teichoic acid production revealed differential patterns in response to each inhibitor. In addition, both inhibitors possessed a bacteriostatic mechanism of action, and neither interfered with the autolytic effects of vancomycin. Cells treated with MN58b but not RSM-932A were more sensitive to a phosphate induced autolysis with respect to the untreated cells. SEM studies revealed that MN58b distorted the cell wall, a result consistent with the apparent teichoic acid changes. Two novel and more highly potent putative inhibitors of sChoK, MN58b and RSM-932A, were characterized in this study. However, the effects of sChoK inhibitors can vary at the cellular level. sChoK inhibition is a promising avenue to follow in the development of therapeutics for treatment of S. pneumoniae.

scholarly journals Combining kinase inhibitors for optimally co‐targeting cancer and drug escape by exploitation of drug target promiscuities

2020 ◽  
Vol 82 (1) ◽  
pp. 133-142
Author(s):  
Shangying Chen ◽  
Sheng Yong Yang ◽  
Xian Zeng ◽  
Feng Zhu ◽  
Ying Tan ◽  
...  
Keyword(s):  
Drug Target ◽  
Kinase Inhibitors

scholarly journals Structural and Enzymatic Characterization of the Choline Kinase LicA from Streptococcus pneumoniae

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0120467 ◽  
Author(s):  
Lei Wang ◽  
Yong-Liang Jiang ◽  
Jing-Ren Zhang ◽  
Cong-Zhao Zhou ◽  
Yuxing Chen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Choline Kinase ◽  
Enzymatic Characterization

Monitoring Drug-Target Interactions through Target Engagement-Mediated Amplification on Arrays and in situ

2021 ◽  
Author(s):  
Rasel Al-Amin ◽  
Lars Johansson ◽  
Eldar Abdurakhmanov ◽  
Nils Landegren ◽  
Liza Löf ◽  
...  
Keyword(s):  
Drug Target ◽  
Kinase Inhibitors ◽  
Expression Profiles ◽  
Clinical Samples ◽  
Target Engagement ◽  
Rolling Circle Replication ◽  
Target Proteins ◽  
Dna Conjugates

Abstract Drugs are designed to bind their target proteins in physiologically relevant tissues and organs to modulate biological functions and elicit desirable clinical outcomes. Information about target engagement at cellular and subcellular resolution is therefore critical for guiding compound optimization in drug discovery, and for probing resistance mechanisms to targeted therapies in clinical samples. We describe a target engagement-mediated amplification (TEMA) technology, where oligonucleotide-conjugated drugs are used to visualize and measure target engagement in situ, amplified via rolling-circle replication of circularized oligonucleotide probes. We illustrate the TEMA technique using dasatinib and gefitinib, two kinase inhibitors with distinct selectivity profiles. In vitro binding by dasatinib probe to arrays of displayed proteins accurately reproduced known selectivity profiles, while their differential binding to a panel of fixed adherent cells agreed with expectations from expression profiles of the cells. These findings were corroborated by competition experiments using kinase inhibitors with overlapping and non-overlapping target specificities, and translated to pathology tissue sections. We also introduce a proximity ligation variant of TEMA in which these drug-DNA conjugates are combined with antibody-DNA conjugates to selectively investigate binding to specific target proteins of interest. This form of the assay serves to improve resolution of binding to on- and off-target proteins. In conclusion, TEMA has the potential to aid in drug development and clinical routine by conferring valuable insights in drug-target interactions at spatial resolution in protein arrays, cells and tissues.

scholarly journals An Application of Fit Quality to Screen MDM2/p53 Protein-Protein Interaction Inhibitors

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3174 ◽  
Author(s):  
Xin Xue ◽  
Gang Bao ◽  
Hai-Qing Zhang ◽  
Ning-Yi Zhao ◽  
Yuan Sun ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Drug Target ◽  
P53 Protein ◽  
Pharmacophore Model ◽  
Cellular Level ◽  
Complex Structures ◽  
Ligand Complex ◽  
Null Cell ◽  
Protein Protein Interaction ◽  
First Time

: The judicious application of ligand or binding efficiency (LE) metrics, which quantify the molecular properties required to obtain binding affinity for a drug target, is gaining traction in the selection and optimization of fragments, hits and leads. Here we report for the first time the use of LE based metric, fit quality (FQ), in virtual screening (VS) of MDM2/p53 protein-protein interaction inhibitors (PPIIs). Firstly, a Receptor-Ligand pharmacophore model was constructed on multiple MDM2/ligand complex structures to screen the library. The enrichment factor (EF) for screening was calculated based on a decoy set to define the screening threshold. Finally, 1% of the library, 335 compounds, were screened and re-filtered with the FQ metric. According to the statistical results of FQ vs activity of 156 MDM2/p53 PPIIs extracted from literatures, the cut-off was defined as FQ = 0.8. After the second round of VS, six compounds with the FQ > 0.8 were picked out for assessing their antitumor activity. At the cellular level, the six hits exhibited a good selectivity (larger than 3) against HepG2 (wt-p53) vs Hep3B (p53 null) cell lines. On the further study, the six hits exhibited an acceptable affinity (range of Ki from 102 to 103 nM) to MDM2 when comparing to Nutlin-3a. Based on our work, FQ based VS strategy could be applied to discover other PPIIs.

Rapid discovery of drug target engagement by isothermal shift assay

2019 ◽  
Author(s):  
Kristofor J. Webb ◽  
Kerri A. Ball ◽  
Stephen J. Coleman ◽  
Jeremy Jacobsen ◽  
Michael H.B. Stowell ◽  
...  
Keyword(s):  
Drug Target ◽  
Drug Targets ◽  
Kinase Inhibitors ◽  
Rapid Identification ◽  
Living Cells ◽  
Experimental Designs ◽  
Living Systems ◽  
Target Engagement ◽  
Protein Targets ◽  
Drug Molecules

Identifying protein targets directly bound by drug molecules within living systems remains challenging. Here we present the isothermal shift assay, iTSA, for rapid identification of drug targets. Compared with thermal proteome profiling, a prevailing method for target engagement, iTSA offers a simplified workflow, 4-fold higher throughput, and multiplexed experimental designs with higher replication. We demonstrate application of iTSA to identify targets for several kinase inhibitors in lysates and living cells.

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