scholarly journals Discovery of Novel Chemical Series of OXA-48 β-Lactamase Inhibitors by High-Throughput Screening

2021 ◽  
Vol 14 (7) ◽  
pp. 612
Author(s):  
Barbara Garofalo ◽  
Federica Prati ◽  
Rosa Buonfiglio ◽  
Isabella Coletta ◽  
Noemi D’Atanasio ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Throughput Screening ◽  
Bacterial Resistance ◽  
X Ray ◽  
Good Solubility ◽  
Competitive Mechanism ◽  
Starting Point ◽  
Compound Collection ◽  
Potential Inhibitors ◽  
Main Strategy

The major cause of bacterial resistance to β-lactams is the production of hydrolytic β-lactamase enzymes. Nowadays, the combination of β-lactam antibiotics with β-lactamase inhibitors (BLIs) is the main strategy for overcoming such issues. Nevertheless, particularly challenging β-lactamases, such as OXA-48, pose the need for novel and effective treatments. Herein, we describe the screening of a proprietary compound collection against Klebsiella pneumoniae OXA-48, leading to the identification of several chemotypes, like the 4-ideneamino-4H-1,2,4-triazole (SC_2) and pyrazolo[3,4-b]pyridine (SC_7) cores as potential inhibitors. Importantly, the most potent representative of the latter series (ID2, AC50 = 0.99 μM) inhibited OXA-48 via a reversible and competitive mechanism of action, as demonstrated by biochemical and X-ray studies; furthermore, it slightly improved imipenem’s activity in Escherichia coli ATCC BAA-2523 β-lactam resistant strain. Also, ID2 showed good solubility and no sign of toxicity up to the highest tested concentration, resulting in a promising starting point for further optimization programs toward novel and effective non-β-lactam BLIs.

The Development of Antibiotics Based on Nanostructured Manganese Oxide; Understanding Mechanism from Fundamental Aspects to Application

2020 ◽  
Vol 20 (12) ◽  
pp. 7618-7628
Author(s):  
Ayesha Taj ◽  
Rabisa Zia ◽  
Sadaf Hameed ◽  
Adnan Mujahid ◽  
Asma Rehman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Manganese Oxide ◽  
Bacterial Resistance ◽  
Bacterial Species ◽  
Spherical Particles ◽  
X Ray ◽  
Atomic Force ◽  
Uv Visible ◽  
Scanning Electron

The emergence of bacterial resistance to currently available antibiotics emphasized the urgent need for new antibacterial agents. Nanotechnology-based approaches are substantially contributing to the development of effective and better-formulated antibiotics. Here, we report the synthesis of stable manganese oxide nanostructures (MnO NS) by a facile, one-step, microwave-assisted method. Asprepared MnO NS were thoroughly characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), UV-Visible spectroscopy and X-ray powder diffraction (XRD). UV-Visible spectra give a sharp absorption peak at a maximum wavelength of 430 nm showed surface plasmon resonance (SPR). X-ray diffraction (XRD) profile demonstrated pure phase and crystalline nature of nanostructures. Morphological investigations by a scanning electron microscope showed good dispersity with spherical particles possessing a size range between 10–100 nm. Atomic force microscope data exhibited that the average size of MnO NS can be controlled between 25 nm to 150 nm by a three-fold increment in the amount of stabilizer (o-phenylenediamine). Antimicrobial activity of MnO NS on both gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) bacterial strains showed that prepared nanostructures were effective against microorganisms. Further, this antibacterial activity was found to be dependent on nanoparticles (NPs) size and bacterial species. These were more effective against Bacillus subtilis (B. subtilis) as compared to Escherichia coli (E. coli). Considering the results together, this study paves the way for the formulation of similar nanostructures as effective antibiotics to kill other pathogens by a more biocompatible platform. This is the first report to synthesize the MnO NS by green approach and its antibacterial application.

Bacterial Transferase MraY, a Source of Inspiration towards New Antibiotics

2019 ◽  
Vol 25 (42) ◽  
pp. 6013-6029 ◽  
Author(s):  
Mickaël J. Fer ◽  
Laurent Le Corre ◽  
Nicolas Pietrancosta ◽  
Nathalie Evrard-Todeschi ◽  
Samir Olatunji ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Bacterial Resistance ◽  
Public Health Problem ◽  
Research Groups ◽  
X Ray ◽  
Peptidoglycan Biosynthesis ◽  
Structure Activity ◽  
New Antibiotics ◽  
Bacterial Peptidoglycan ◽  
Further Development

The bacterial resistance to antibiotics constitutes more than ever a severe public health problem. The enzymes involved in bacterial peptidoglycan biosynthesis are pertinent targets for developing new antibiotics, notably the MraY transferase that is not targeted by any marketed drug. Many research groups are currently working on the study or the inhibition of this enzyme. After a concise overview of the role, mechanism and inhibition of MraY, the structure–activity relationships of 5’-triazole-containing aminoribosyluridine inhibitors, we previously synthetized, will be presented. The recently published MraY X-ray structures allowed us to achieve a molecular virtual high-throughput screening of commercial databases and our in-house library resulting in the identification of promising compounds for the further development of new antibiotics.

Crystallization and preliminary X-ray diffraction analysis of the homodimeric form α2 of the HU protein from Escherichia coli

1999 ◽  
Vol 55 (11) ◽  
pp. 1952-1954 ◽  
Author(s):  
Franck Coste ◽  
Nadège Hervouet ◽  
Jacques Oberto ◽  
Charles Zelwer ◽  
Bertrand Castaing
Keyword(s):  
Escherichia Coli ◽  
Bacillus Stearothermophilus ◽  
Diffusion Method ◽  
Data Set ◽  
X Ray ◽  
Cell Parameters ◽  
Replacement Method ◽  
Starting Point ◽  
Molecular Replacement Method ◽  
Reliable Solution

The homodimeric form α2 of the Escherichia coli DNA-binding protein HU was crystallized by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The crystals belong to space group I222, with unit-cell parameters a = 31.09, b = 55.34, c = 117.63 Å, and contain one monomer per asymmetric unit. A full diffraction data set was collected to 2.3 Å resolution on a conventional X-ray source. The molecular-replacement method, using the HU crystallographic model from Bacillus stearothermophilus as a starting point, gave a reliable solution for the rotation and translation functions.

scholarly journals Development of a High-Throughput Screening Assay to Identify Inhibitors of the SARS-CoV-2 Guanine-N7-Methyltransferase Using RapidFire Mass Spectrometry

2021 ◽  
pp. 247255522110006
Author(s):  
Lesley-Anne Pearson ◽  
Charlotte J. Green ◽  
De Lin ◽  
Alain-Pierre Petit ◽  
David W. Gray ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Mutational Analysis ◽  
Nonstructural Protein ◽  
Translation Efficiency ◽  
Screening Assay ◽  
High Throughput Screening Assay ◽  
Starting Point ◽  
Approved Drugs ◽  
High Throughput Assay

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.

scholarly journals Crystallization and Preliminary X-ray Characterization of Thioredoxin Reductase from Escherichia coli

1989 ◽  
Vol 264 (22) ◽  
pp. 12752-12753
Author(s):  
J Kuriyan ◽  
L Wong ◽  
M Russel ◽  
P Model
Keyword(s):  
Escherichia Coli ◽  
Thioredoxin Reductase ◽  
X Ray
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