Dipeptidic Phosphonates: Potent Inhibitors of Pseudomonas aeruginosa Elastase B Showing Efficacy in a Murine Keratitis Model.

The ubiquitous opportunistic pathogen Pseudomonas aeruginosa is responsible for severe infections and notoriously known for acquiring antimicrobial resistance. Inhibiting the bacterium's extracellular elastase, LasB - a zinc-dependent protease - presents a promising strategy to mitigate its virulence. Within this medicinal chemistry-driven hit-to-lead optimization campaign, a new series of highly potent dipeptidic phosphonates is designed and synthesized following a structure-based drug-discovery approach.

From Dyrk1A inhibitors to a novel class of antiviral agents: Targeting Enterovirus EV-A71 with 2-aryl-substituted thiophene scaffolds.

Enterovirus A71 (EV-A71) is a major causative agent of hand, foot, and mouth disease (HFMD) especially in children. The majority of EV-A71 cases are mild, however, severe cases have exhibited an array of neurological complications which often lead to death. In a screening campaign to discover hits against EV-A71, we identified six 2,4-diaryl-substituted thiophene compounds that were previously reported as Dyrk1A inhibitors.

YgiV promoter mutations cause resistance to cystobactamids and reduced virulence factor expression in Escherichia coli.

Antimicrobial resistance is one of the major health threats of the modern world. Thus, new structural classes of antimicrobial compounds are needed in order to overcome existing resistance. Cystobactamids represent one such new compound class that inhibit the well-established target bacterial type II topoisomerases while exhibiting superior antibacterial and resistance-breaking properties.

Apo structure of Mycobacterium tuberculosis 1-deoxy-d-xylulose 5-phosphate synthase DXPS: Dynamics and implications for inhibitor design.

The enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXPS) catalyses the first step of the MEP pathway, a key process for isoprenoid biosynthesis in bacteria that is absent in humans, making it a promising drug target. We present the structure of Mycobacterium tuberculosis DXPS in its apo form, obtained through a soaking method that removes thiamine diphosphate (ThDP) and metals from pre-formed crystals. The apo structure had three regions with absence of electron density near the active site that are unique to the apo form of the enzyme.

Targeting IspD for Anti-infective and Herbicide Development: Exploring Its Role, Mechanism, and Structural Insights.

Antimicrobial resistance (AMR) and herbicide resistance pose threats to society, necessitating novel anti-infectives and herbicides exploiting untapped modes of action like inhibition of IspD, the third enzyme in the MEP pathway. The MEP pathway is essential for a wide variety of human pathogens, including , , and as well as plants. Within the current perspective, we focused our attention on the third enzyme in this pathway, IspD, offering a comprehensive summary of the reported modes of inhibition and common trends, with the goal to inspire future research dedicated to this underexplored target.

Fragment Discovery by X-Ray Crystallographic Screening Targeting the CTP Binding Site of Pseudomonas Aeruginosa IspD.

With antimicrobial resistance (AMR) reaching alarming levels, new anti-infectives with unprecedented mechanisms of action are urgently needed. The 2-C-methylerythritol-D-erythritol-4-phosphate (MEP) pathway represents an attractive source of drug targets due to its essential role in numerous pathogenic Gram-negative bacteria and Mycobacterium tuberculosis (Mt), whilst being absent in human cells. Here, we solved the first crystal structure of Pseudomonas aeruginosa (Pa) IspD, the third enzyme in the MEP pathway and present the discovery of a fragment-based compound class identified through crystallographic screening of PaIspD.

Integral Solvent-Induced Protein Precipitation for Target-Engagement Studies in .

The limited understanding of the mechanism of action (MoA) of several antimalarials and the rise of drug resistance toward existing malaria therapies emphasizes the need for new strategies to uncover the molecular target of compounds in . Integral solvent-induced protein precipitation (iSPP) is a quantitative mass spectrometry-based (LC-MS/MS) proteomics technique. The iSPP leverages the change in solvent-induced denaturation of the drug-bound protein relative to its unbound state, allowing identification of the direct drug-protein target without the need to modify the drug.

Studying Target-Engagement of Anti-Infectives by Solvent-Induced Protein Precipitation and Quantitative Mass Spectrometry.

Antimicrobial resistance (AMR) poses a serious threat to global health. The rapid emergence of resistance contrasts with the slow pace of antimicrobial development, emphasizing the urgent need for innovative drug discovery approaches. This study addresses a critical bottleneck in early drug development by introducing integral solvent-induced protein precipitation (iSPP) to rapidly assess the target-engagement of lead compounds in extracts of pathogenic microorganisms under close-to-physiological conditions.

Targeting the IspE Enzyme.

The enzyme IspE in is considered an attractive drug target, as it is essential for parasite survival and is absent in the human proteome. Yet it still has not been addressed by a small-molecule inhibitor. In this study, we conducted a high-throughput screening campaign against the IspE enzyme.

IspE kinase as an anti-infective target: Role of a hydrophobic pocket in inhibitor binding.

Enzymes of the methylerythritol phosphate (MEP) pathway are potential targets for antimicrobial drug discovery. Here, we focus on 4-diphosphocytidyl-2-C-methyl-D-erythritol (IspE) kinase from the MEP pathway. We use biochemical and structural biology methods to investigate homologs from pathogenic microorganisms; Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii.

Expression and characterization of pantothenate energy-coupling factor transporters as an anti-infective drug target.

This study investigates the potential of energy-coupling factor (ECF) transporters as promising anti-infective targets to combat antimicrobial resistance (AMR). ECF transporters, a subclass of ATP-binding cassette (ABC) transporters, facilitate the uptake of B-vitamins across bacterial membranes by utilizing ATP as an energy source. Vitamins are essential cofactors for bacterial metabolism and growth, and they can either be synthesized de novo or absorbed from the environment.

Development of Fragment-Based Inhibitors of the Bacterial Deacetylase LpxC with Low Nanomolar Activity.

In a fragment-based approach using NMR spectroscopy, benzyloxyacetohydroxamic acid-derived inhibitors of the bacterial deacetylase LpxC bearing a substituent to target the uridine diphosphate-binding site of the enzyme were developed. By appending privileged fragments via a suitable linker, potent LpxC inhibitors with promising antibacterial activities could be obtained, like the one-digit nanomolar LpxC inhibitor ()- [ (LpxC C63A) = 9.5 nM; (LpxC): 5.

Targeting IspD in the Methyl-d-erythritol Phosphate Pathway: Urea-Based Compounds with Nanomolar Potency on Target and Low-Micromolar Whole-Cell Activity.

The methyl-d-erythritol phosphate (MEP) pathway has emerged as an interesting target in the fight against antimicrobial resistance. The pathway is essential in many human pathogens, including (), but is absent in human cells. In the present study, we report on the discovery of a new chemical class targeting IspD, the third enzyme in the pathway.

Target-Directed Dynamic Combinatorial Chemistry Affords Binders of IspE.

In the search for new antitubercular compounds, we leveraged target-directed dynamic combinatorial chemistry (tdDCC) as an efficient hit-identification method. In tdDCC, the target selects its own binders from a dynamic library generated , reducing the number of compounds that require synthesis and evaluation. We combined a total of 12 hydrazides and six aldehydes to generate 72 structurally diverse -acylhydrazones.

Dual inhibitors of virulence factors LecA and LasB.

Dual inhibitors of two key virulence factors of , the lectin LecA and the protease LasB, open up an opportunity in the current antimicrobial-resistance crisis. A molecular hybridization approach enabled the discovery of potent, selective, and non-toxic thiol-based inhibitors, which simultaneously inhibit these two major extracellular virulence factors and therefore synergistically interfere with virulence. We further demonstrated that the dimerization of these monovalent dual inhibitors under physiological conditions affords divalent inhibitors of LecA with a 200-fold increase in binding affinity.

Cryo-EM structure of 1-deoxy-D-xylulose 5-phosphate synthase DXPS from Plasmodium falciparum reveals a distinct N-terminal domain.

Plasmodium falciparum is the main causative agent of malaria, a deadly disease that mainly affects children under five years old. Artemisinin-based combination therapies have been pivotal in controlling the disease, but resistance has arisen in various regions, increasing the risk of treatment failure. The non-mevalonate pathway is essential for the isoprenoid synthesis in Plasmodium and provides several under-explored targets to be used in the discovery of new antimalarials.

Isocyanides inhibit bacterial pathogens by covalent targeting of essential metabolic enzymes.

Isonitrile natural products, also known as isocyanides, demonstrate potent antimicrobial activities, yet our understanding of their molecular targets remains limited. Here, we focus on the so far neglected group of monoisonitriles to gain further insights into their antimicrobial mode of action (MoA). Screening a focused monoisonitrile library revealed a potent growth inhibitor with a different MoA compared to previously described isonitrile antibiotics.

Discovery and optimization of thiazole-based quorum sensing inhibitors as potent blockers of Pseudomonas aeruginosa pathogenicity.

Pseudomonas aeruginosa causes life-threatening infections especially in hospitalized patients and shows an increasing resistance to established antibiotics. A process known as quorum sensing (QS) enables the pathogen to collectively adapt to various environmental conditions. Disrupting this cell-to-cell communication machinery by small-molecular entities leads to a blockade of bacterial pathogenicity.

Target repurposing unravels avermectins and derivatives as novel antibiotics inhibiting energy-coupling factor transporters (ECFTs).

Energy-coupling factor transporters (ECFTs) are membrane-bound ATP-binding cassette (ABC) transporters in prokaryotes that are found in pathogens against which novel antibiotics are urgently needed. To date, just 54 inhibitors of three molecular-structural classes with mostly weak inhibitory activity are known. Target repurposing is a strategy that transfers knowledge gained from a well-studied protein family to under-studied targets of phylogenetic relation.

Thermotropic liquid crystals in drug delivery: A versatile carrier for controlled release.

Responsive and adaptive soft-matter systems represent an advanced category of materials with potential applications in drug delivery. Among these, liquid crystals (LCs) emerge as multifunctional anisotropic scaffolds capable of reacting to temperature, light, electric or magnetic fields. Specifically, the ordering and physical characteristics of thermotropic LCs are primarily contingent on temperature as an external stimulus.

Arg-biodynamers as antibiotic potentiators through interacting with Gram-negative outer membrane lipopolysaccharides.

Antimicrobial resistance is becoming more prominent day after day due to a number of mechanisms by microbes, especially the sophisticated biological barriers of bacteria, especially in Gram-negatives. There, the lipopolysaccharides (LPS) layer is a unique component of the outer leaflet of the outer membrane which is highly impermeable and prevents antibiotics from passing passively into the intracellular compartments. Biodynamers, a novel class of dynamically bio-responsive polymers, may open new perspectives to overcome this particular barrier by accommodating various secondary structures and form supramolecular structures in such bacterial microenvironments.

Biodynamer Nano-Complexes and -Emulsions for Peptide and Protein Drug Delivery.

Background: Therapeutic proteins and peptides offer great advantages compared to traditional synthetic molecular drugs. However, stable protein loading and precise control of protein release pose significant challenges due to the extensive range of physicochemical properties inherent to proteins. The development of a comprehensive protein delivery strategy becomes imperative accounting for the diverse nature of therapeutic proteins.

Evaluation of ketoclomazone and its analogues as inhibitors of 1-deoxy-d-xylulose 5-phosphate synthases and other thiamine diphosphate (ThDP)-dependent enzymes.

Most pathogenic bacteria, apicomplexan parasites and plants rely on the methylerythritol phosphate (MEP) pathway to obtain precursors of isoprenoids. 1-Deoxy-d-xylulose 5-phosphate synthase (DXPS), a thiamine diphosphate (ThDP)-dependent enzyme, catalyses the first and rate-limiting step of the MEP pathway. Due to its absence in humans, DXPS is considered as an attractive target for the development of anti-infectious agents and herbicides.