scholarly journals Stress-Based High-Throughput Screening Assays to Identify Inhibitors of Cell Envelope Biogenesis

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 808
Author(s):  
Maurice Steenhuis ◽  
Corinne M. ten Hagen-Jongman ◽  
Peter van Ulsen ◽  
Joen Luirink

The structural integrity of the Gram-negative cell envelope is guarded by several stress responses, such as the σE, Cpx and Rcs systems. Here, we report on assays that monitor these responses in E. coli upon addition of antibacterial compounds. Interestingly, compromised peptidoglycan synthesis, outer membrane biogenesis and LPS integrity predominantly activated the Rcs response, which we developed into a robust HTS (high-throughput screening) assay that is suited for phenotypic compound screening. Furthermore, by interrogating all three cell envelope stress reporters, and a reporter for the cytosolic heat-shock response as control, we found that inhibitors of specific envelope targets induce stress reporter profiles that are distinct in quality, amplitude and kinetics. Finally, we show that by using a host strain with a more permeable outer membrane, large-scaffold antibiotics can also be identified by the reporter assays. Together, the data suggest that stress profiling is a useful first filter for HTS aimed at inhibitors of cell envelope processes.

2015 ◽  
Vol 21 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Mathew Hanson ◽  
Lorne D. Jordan ◽  
Yan Shipelskiy ◽  
Salete M. Newton ◽  
Phillip E. Klebba

The TonB-dependent Gram-negative bacterial outer membrane protein FepA actively transports the siderophore ferric enterobactin (FeEnt) into the periplasm. We developed a high-throughput screening (HTS) assay that observes FeEnt uptake through FepA in living Escherichia coli, by monitoring fluorescence quenching that occurs upon binding of FeEnt, and then unquenching as the bacteria deplete it from solution by transport. We optimized the labeling and spectroscopic methods to screen for inhibitors of TonB-dependent iron uptake through the outer membrane. The assay works like a molecular switch that is on in the presence of TonB activity and off in its absence. It functions in 96-well microtiter plates, in a variety of conditions, with Z factors of 0.8–1.0. TonB-dependent iron transport is energy dependent, and the inhibitory effects of the metabolic inhibitors carbonyl cyanide m-chlorophenylhydrazone, 2,4-dinitrophenol, azide, cyanide, and arsenate on FeEnt uptake were readily detected by the assay. Because iron acquisition is a determinant of bacterial pathogenesis, HTS with this method may identify inhibitors that block TonB function and constitute novel therapeutics against infectious disease caused by Gram-negative bacteria.


2004 ◽  
Vol 9 (2) ◽  
pp. 112-121 ◽  
Author(s):  
Steven N. Anderson ◽  
Barbara L. Cool ◽  
Lemma Kifle ◽  
William Chiou ◽  
David A. Egan ◽  
...  

A novel and innovative high-throughput screening assay was developed to identify both activators and inhibitors of AMP-activated protein kinase (AMPK) using microarrayed compound screening (μARCS) technology. Test compounds were arrayed at a density of 8640 on a polystyrene sheet, and the enzyme and peptide substrate were introduced into the assay by incorporating them into an agarose gel followed by placement of the gels onto the compound sheet. Adenosine triphosphate (ATP) was delivered via a membrane, and the phosphorylated biotinylated substrate was captured onto a streptavidin affinity membrane (SAM™). For detection, the SAM™ was removed, washed, and imaged on a phosphor screen overnight. A library of more than 700,000 compounds was screened using this format to identify novel activators and inhibitors of AMPK. ( Journal of Biomolecular Screening 2004:112-121)


2018 ◽  
Vol 20 (9) ◽  
pp. 804-819 ◽  
Author(s):  
Mohamed Boudjelal ◽  
Ana Maria Ruiz-Avendano ◽  
Gonzalo Colmenarejo ◽  
Sergio A. Senar-Sancho ◽  
Ashley Barnes ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sadaf Kalsum ◽  
Blanka Andersson ◽  
Jyotirmoy Das ◽  
Thomas Schön ◽  
Maria Lerm

Abstract Background Efficient high-throughput drug screening assays are necessary to enable the discovery of new anti-mycobacterial drugs. The purpose of our work was to develop and validate an assay based on live-cell imaging which can monitor the growth of two distinct phenotypes of Mycobacterium tuberculosis and to test their susceptibility to commonly used TB drugs. Results Both planktonic and cording phenotypes were successfully monitored as fluorescent objects using the live-cell imaging system IncuCyte S3, allowing collection of data describing distinct characteristics of aggregate size and growth. The quantification of changes in total area of aggregates was used to define IC50 and MIC values of selected TB drugs which revealed that the cording phenotype grew more rapidly and displayed a higher susceptibility to rifampicin. In checkerboard approach, testing pair-wise combinations of sub-inhibitory concentrations of drugs, rifampicin, linezolid and pretomanid demonstrated superior growth inhibition of cording phenotype. Conclusions Our results emphasize the efficiency of using automated live-cell imaging and its potential in high-throughput whole-cell screening to evaluate existing and search for novel antimycobacterial drugs.


2021 ◽  
pp. 247255522110006
Author(s):  
Lesley-Anne Pearson ◽  
Charlotte J. Green ◽  
De Lin ◽  
Alain-Pierre Petit ◽  
David W. Gray ◽  
...  

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a significant threat to human health. Despite its similarity to related coronaviruses, there are currently no specific treatments for COVID-19 infection, and therefore there is an urgent need to develop therapies for this and future coronavirus outbreaks. Formation of the cap at the 5′ end of viral RNA has been shown to help coronaviruses evade host defenses. Nonstructural protein 14 (nsp14) is responsible for N7-methylation of the cap guanosine in coronaviruses. This enzyme is highly conserved among coronaviruses and is a bifunctional protein with both N7-methyltransferase and 3′-5′ exonuclease activities that distinguish nsp14 from its human equivalent. Mutational analysis of SARS-CoV nsp14 highlighted its role in viral replication and translation efficiency of the viral genome. In this paper, we describe the characterization and development of a high-throughput assay for nsp14 utilizing RapidFire technology. The assay has been used to screen a library of 1771 Food and Drug Administration (FDA)-approved drugs. From this, we have validated nitazoxanide as a selective inhibitor of the methyltransferase activity of nsp14. Although modestly active, this compound could serve as a starting point for further optimization.


PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0129234 ◽  
Author(s):  
Lauren Forbes ◽  
Katherine Ebsworth-Mojica ◽  
Louis DiDone ◽  
Shao-Gang Li ◽  
Joel S. Freundlich ◽  
...  

2012 ◽  
Vol 56 (6) ◽  
pp. 3399-3401 ◽  
Author(s):  
Kevin D. McCormick ◽  
Shufeng Liu ◽  
Jana L. Jacobs ◽  
Ernesto T. A. Marques ◽  
Nicolas Sluis-Cremer ◽  
...  

ABSTRACTWe have developed a robust cytopathic effect-based high-throughput screening assay to identify inhibitors of dengue virus (DENV) infection. Screening of a small natural product library yielded 11 hits. Four of these were found to be potent inhibitors of DENV, although serotype differences were noted. Taken together, these data suggest that screening of larger and more complex molecule libraries may result in the identification of more potent and specific DENV inhibitors.


PLoS ONE ◽  
2018 ◽  
Vol 13 (12) ◽  
pp. e0208641
Author(s):  
Wolfgang Klein ◽  
Claudia Rutz ◽  
Jamina Eckhard ◽  
Becky Provinciael ◽  
Edgar Specker ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document