Pulcherriminic acid biosynthesis and transport: insights from a heterologous system in Saccharomyces cerevisiae.

Pulcherriminic acid is an iron chelator produced by some Kluyveromyces and Metschnikowia yeasts. Its biosynthesis is encoded by the four-gene PUL cluster, where PUL1 and PUL2 are the biosynthetic enzymes, PUL3 mediates the uptake of iron-bound pulcherrimin, and PUL4 is a putative regulator. Pulcherriminic acid holds antifungal potential, as the growth of organisms unable to uptake pulcherrimin is inhibited by deficit of essential iron.

Phantom Tumor: A Diagnostic Challenge.

The vanishing or phantom tumor of the lung is an uncommon condition that is caused by an interlobar pleural collection of transudative fluid, resulting from pulmonary congestion. The diagnosis is typically made via chest X-ray, where it appears as a nodular opacity, often mistaken for a pulmonary tumor, hence the term "phantom tumor." This condition is most frequently associated with systemic diseases such as heart failure or chronic kidney disease.

Actinomycosis With Pulmonary and Hepatic Involvement: A Case Report and Clinical Insights.

Actinomycosis is a rare, chronic infectious disease caused by Actinomyces spp., characterized by an indolent and slowly progressive course. It represents a diagnostic challenge since its nonspecific clinical features often lead to misdiagnosis, mimicking pathologies such as solid neoplasms, active tuberculosis, nocardiosis, fungal infections, or other granulomatous diseases.

Correction: Oliveira et al. Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses. 2023, , 3531.

In the published publication [...

Impact of the Cationic Moiety of Ionic Liquids on Chemoselective Artificial Olfaction.

Ionogels and derived materials are assemblies of polymers and ionic liquids characterized by high stability and ionic conductivity, making them interesting choices as gas sensors. In this work, we assessed the effect of the ionic liquid moiety to generate ionogels and hybrid gels as electrical and optical gas sensors. Six ionic liquids consisting of a constant anion (chloride) and distinct cationic head groups were used to generate ionogels and hybrid gels and further tested as gas sensors in customized electronic nose devices.

An allosteric redox switch involved in oxygen protection in a CO reductase.

Metal-dependent formate dehydrogenases reduce CO with high efficiency and selectivity, but are usually very oxygen sensitive. An exception is Desulfovibrio vulgaris W/Sec-FdhAB, which can be handled aerobically, but the basis for this oxygen tolerance was unknown. Here we show that FdhAB activity is controlled by a redox switch based on an allosteric disulfide bond.

Carboxysome-Inspired Electrocatalysis using Enzymes for the Reduction of CO at Low Concentrations.

The electrolysis of dilute CO streams suffers from low concentrations of dissolved substrate and its rapid depletion at the electrolyte-electrocatalyst interface. These limitations require first energy-intensive CO capture and concentration, before electrolyzers can achieve acceptable performances. For direct electrocatalytic CO reduction from low-concentration sources, we introduce a strategy that mimics the carboxysome in cyanobacteria by utilizing microcompartments with nanoconfined enzymes in a porous electrode.

Effect of Polymer Hydrophobicity in the Performance of Hybrid Gel Gas Sensors for E-Noses.

Relative humidity (RH) is a common interferent in chemical gas sensors, influencing their baselines and sensitivity, which can limit the performance of e-nose systems. Tuning the composition of the sensing materials is a possible strategy to control the impact of RH in gas sensors. Hybrid gel materials used as gas sensors contain self-assembled droplets of ionic liquid and liquid crystal molecules encapsulated in a polymeric matrix.

The Biology of Lysosomes: From Order to Disorder.

Since its discovery in 1955, the understanding of the lysosome has continuously increased. Once considered a mere waste removal system, the lysosome is now recognised as a highly crucial cellular component for signalling and energy metabolism. This notable evolution raises the need for a summarized review of the lysosome's biology.

Tracking W-Formate Dehydrogenase Structural Changes During Catalysis and Enzyme Reoxidation.

Metal-dependent formate dehydrogenases (Fdh) catalyze the reversible conversion of CO to formate, with unrivalled efficiency and selectivity. However, the key catalytic aspects of these enzymes remain unknown, preventing us from fully benefiting from their capabilities in terms of biotechnological applications. Here, we report a time-resolved characterization by X-ray crystallography of the Hildenborough SeCys/W-Fdh during formate oxidation.

Spectroscopic and Structural Characterization of Reduced Hildenborough W-FdhAB Reveals Stable Metal Coordination during Catalysis.

Metal-dependent formate dehydrogenases are important enzymes due to their activity of CO reduction to formate. The tungsten-containing FdhAB formate dehydrogenase from Hildenborough is a good example displaying high activity, simple composition, and a notable structural and catalytic robustness. Here, we report the first spectroscopic redox characterization of FdhAB metal centers by EPR.

Elucidating Film Loss and the Role of Hydrogen Bonding of Adsorbed Redox Enzymes by Electrochemical Quartz Crystal Microbalance Analysis.

The immobilization of redox enzymes on electrodes enables the efficient and selective electrocatalysis of useful reactions such as the reversible interconversion of dihydrogen (H) to protons (H) and formate to carbon dioxide (CO) with hydrogenase (Hase) and formate dehydrogenase (FDH), respectively. However, their immobilization on electrodes to produce electroactive protein films for direct electron transfer (DET) at the protein-electrode interface is not well understood, and the reasons for their activity loss remain vague, limiting their performance often to hour timescales. Here, we report the immobilization of [NiFeSe]-Hase and [W]-FDH from Hildenborough on a range of charged and neutral self-assembled monolayer (SAM)-modified gold electrodes with varying hydrogen bond (H-bond) donor capabilities.

Understanding the local chemical environment of bioelectrocatalysis.

Bioelectrochemistry employs an array of high-surface-area meso- and macroporous electrode architectures to increase protein loading and the electrochemical current response. While the local chemical environment has been studied in small-molecule and heterogenous electrocatalysis, conditions in enzyme electrochemistry are still commonly established based on bulk solution assays, without appropriate consideration of the nonequilibrium conditions of the confined electrode space. Here, we apply electrochemical and computational techniques to explore the local environment of fuel-producing oxidoreductases within porous electrode architectures.

A Semi-artificial Photoelectrochemical Tandem Leaf with a CO -to-Formate Efficiency Approaching 1 .

Semi-artificial photoelectrochemistry can combine state-of-the-art photovoltaic light-absorbers with enzymes evolved for selective fuel-forming reactions such as CO reduction, but the overall performance of such hybrid systems has been limited to date. Here, the electrolyte constituents were first tuned to establish an optimal local environment for a W-formate dehydrogenase to perform electrocatalysis. The CO reductase was then interfaced with a triple cation lead mixed-halide perovskite through a hierarchically structured porous TiO scaffold to produce an integrated photocathode achieving a photocurrent density of -5 mA cm at 0.

Heavy Metals Removal from Aqueous Solutions by Multiwall Carbon Nanotubes: Effect of MWCNTs Dispersion.

Carbon nanotubes (CNTs) are one of the most studied nanoparticles due to their physical, chemical and electronic properties. However, strong Van der Waals bonds, which promote CNTs aggregation are usually present, affecting their unique properties. Avoiding CNTs aggregation is one of the main difficulties when using these nanoparticles.

Generation and characterization of induced pluripotent stem cells heterozygous for the Portuguese BRCA2 founder mutation.

Women who inherit heterozygous mutations in the BRCA2 gene have an increased risk of developing cancer, mainly breast and ovarian tumors. A particular BRCA2 mutation (c.156_157insAlu) is exclusively found in families of Portuguese ancestry and is present in approximately 30% of all Portuguese families with hereditary breast and ovarian cancers.

Generation and characterization of induced pluripotent stem cells from a family carrying the BRCA1 mutation c.3612delA.

How BRCA1 germline mutations predispose to cancer remains poorly understood. Induced pluripotent stem cells (iPSCs) represent an emerging model to investigate the molecular mechanisms underlying malignant transformation in primary cells from individuals who are carriers of deleterious mutations in the BRCA1 gene. Here we report the generation and characterization of iPSC lines from a female donor harboring a germline c.

Formate Dehydrogenases Reduce CO Rather than HCO : An Electrochemical Demonstration.

Mo/W formate dehydrogenases catalyze the reversible reduction of CO species to formate. It is thought that the substrate is CO and not a hydrated species like HCO , but there is still no indisputable evidence for this, in spite of the extreme importance of the nature of the substrate for mechanistic studies. We devised a simple electrochemical method to definitively demonstrate that the substrate of formate dehydrogenases is indeed CO .

Fine Particulate Matter and Gaseous Compounds in Kitchens and Outdoor Air of Different Dwellings.

Passive diffusion tubes for volatile organic compounds (VOCs) and carbonyls and low volume particulate matter (PM) samplers were used simultaneously in kitchens and outdoor air of four dwellings. PM filters were analysed for their carbonaceous content (organic and elemental carbon, OC and EC) by a thermo-optical technique and for polycyclic aromatic hydrocarbon (PAHs) and plasticisers by GC-MS. The morphology and chemical composition of selected PM samples were characterised by SEM-EDS.

Spontaneous reports of hypersensitivity adverse drug reactions in Portugal: a retrospective analysis.

Background: Hypersensitivity adverse drug reactions (ADRs) are usually serious, unpredictable, and associated with high morbidity and mortality. This study describes cases of hypersensitivity ADRs spontaneously reported in Central Portugal.

Methods: Spontaneous reports (SRs) of ADRs received between 2010 and 2017 were reviewed to identify cases of hypersensitivity reactions, using a Standardized MedDRA Query (SMQ).

Interfacing Formate Dehydrogenase with Metal Oxides for the Reversible Electrocatalysis and Solar-Driven Reduction of Carbon Dioxide.

The integration of enzymes with synthetic materials allows efficient electrocatalysis and production of solar fuels. Here, we couple formate dehydrogenase (FDH) from Desulfovibrio vulgaris Hildenborough (DvH) to metal oxides for catalytic CO reduction and report an in-depth study of the resulting enzyme-material interface. Protein film voltammetry (PFV) demonstrates the stable binding of FDH on metal-oxide electrodes and reveals the reversible and selective reduction of CO to formate.