Prog Nucl Magn Reson Spectrosc
December 2024
In recent years, there has been remarkable progress in the field of dissolution dynamic nuclear polarization (D-DNP). This method has shown significant potential for enhancing nuclear polarization by over 10,000 times, resulting in a substantial increase in sensitivity. The unprecedented signal enhancements achieved with D-DNP have opened new possibilities for in vitro analysis.
View Article and Find Full Text PDFThe hyperpolarization of biological samples using dissolution dynamic nuclear polarization (dDNP) has become an attractive method for the monitoring of fast chemical and enzymatic reactions using NMR by taking advantage of a large signal increase. This approach is actively developing but still needs key methodological breakthroughs to be used as an analytical method for the monitoring of complex networks of simultaneous metabolic pathways. In this article, we use the deceptively simple example of glucose-6-phosphate (G6P) oxidation reaction by the enzyme G6P dehydrogenase (G6PDH) to discuss some important methodological aspects of dDNP kinetic experiments, such as its robustness and its ability to provide repeatable results as well as the capacity of this time-resolved methodology to test kinetic models and hypotheses and to provide reliable parameter estimates.
View Article and Find Full Text PDFBlast disease caused by the fungus Magnaporthe oryzae is one of the most devastating rice diseases. Disease resistance genes such as Pi-ta or Pi-ta2 are critical in protecting rice production from blast. Published work reports that Pi-ta codes for a nucleotide-binding and leucine-rich repeat domain protein (NLR) that recognizes the fungal protease-like effector AVR-Pita by direct binding.
View Article and Find Full Text PDFThe highly conserved angiosperm immune receptor HOPZ-ACTIVATED RESISTANCE 1 (ZAR1) is a bacterial pathogen recognition hub that mediates resistance by guarding host kinases for modification by pathogen effectors. The pseudokinase HOPZ-ETI DEFICIENT 1 (ZED1) is the only known ZAR1-guarded protein that interacts directly with a pathogen effector, HopZ1a, from the bacterial pathogen Pseudomonas syringae, making it a promising system for rational design of effector recognition for plant immunity. Here, we conducted an in-depth molecular analysis of ZED1.
View Article and Find Full Text PDFLanifibranor, a pan-PPAR agonist, improves liver histology in patients with metabolic dysfunction-associated steatohepatitis (MASH), who have poor cardiometabolic health (CMH) and cardiovascular events as major mortality cause. NATIVE trial secondary and exploratory outcomes (ClinicalTrials.gov NCT03008070) were analyzed for the effect of lanifibranor on IR, lipid and glucose metabolism, systemic inflammation, blood pressure (BP), hepatic steatosis (imaging and histological grading) for all patients of the original analysis.
View Article and Find Full Text PDFThe supramolecular interaction between lanthanide complexes and proteins is at the heart of numerous chemical and biological studies. Some of these complexes have demonstrated remarkable interaction properties with proteins or peptides in solution and in the crystalline state. Here we have used the paramagnetism of lanthanide ions to characterize the affinity of two lanthanide complexes for ubiquitin.
View Article and Find Full Text PDFDynamical nuclear polarization (DNP) is a powerful method that allows one to polarize virtually any spin-bearing nucleus by transferring electron polarization by microwave irradiation of the electron Zeeman transitions. Under certain conditions, the DNP process can be described in thermodynamical terms using the thermal mixing (TM) model. Different nuclear species can exchange energy indirectly through their interactions with the electron spins and reach a common spin temperature.
View Article and Find Full Text PDFThe highly conserved angiosperm immune receptor HOPZ-ACTIVATED RESISTANCE1 (ZAR1) recognises the activity of diverse pathogen effector proteins by monitoring the ZED1-related kinase (ZRK) family. Understanding how ZAR1 achieves interaction specificity for ZRKs may allow for the expansion of the ZAR1-kinase recognition repertoire to achieve novel pathogen recognition outside of model species. We took advantage of the natural diversity of Arabidopsis thaliana kinases to probe the ZAR1-kinase interaction interface and found that A.
View Article and Find Full Text PDFGlutamine is under scrutiny regarding its metabolic deregulation linked to energetic reprogramming in cancer cells. Many analytical techniques have been used to better understand the impact of the metabolism of amino acids on biological processes, however only a few are suited to work with complex samples. Here, we report the use of a general dissolution dynamic nuclear polarization (D-DNP) formulation using an unexpensive radical as a multipurpose tool to study glutamine, with insights from enzymatic modelling to complex metabolic networks and fast imaging.
View Article and Find Full Text PDFBackground: Renal oligohydramnios (ROH) is caused by bilateral congenital abnormalities, either of renal parenchymal or obstructive origin. ROH is a poor prognostic factor of neonatal survival; lung hypoplasia is reported to be the main cause of mortality. We aimed to describe the fetal morbidity and pre- and postnatal mortality in case of ROH due to renal congenital pathologies and to find predictive risk factors for morbidity and mortality.
View Article and Find Full Text PDFOil is extracted from walnut leaves behind large quantities of defatted press cake that is still rich in valuable nutrients. and , two molds traditionally used in Asia, have the necessary enzymes to use the nutrients in the walnut press cake. Walnuts and the press cake contain ellagitannins, known as precursors for ellagic acid and urolithins.
View Article and Find Full Text PDFFlaxseeds are typically consumed either as whole flaxseed, ground flaxseed, flaxseed oil, partially defatted flaxseed meal, or as a milk alternative. They are considered a rich source of vitamins, minerals, proteins and peptides, lipids, carbohydrates, lignans, and dietary fiber, which have shown hypolipidemic, antiatherogenic, anticholesterolemic, and anti-inflammatory property activity. Here, an in vitro batch culture model was used to investigate the influence of whole milled flaxseed and partially defatted milled flaxseed press cake on the gut microbiota and the liberation of flaxseed bioactives.
View Article and Find Full Text PDFPlant diseases are an important threat to food production. While major pathogenicity determinants required for disease have been extensively studied, less is known on how pathogens thrive during host colonization, especially at early infection stages. Here, we used randomly barcoded-transposon insertion site sequencing (RB-TnSeq) to perform a genome-wide screen and identify key bacterial fitness determinants of the vascular pathogen Xanthomonas campestris pv campestris (Xcc) during infection of the cauliflower host plant (Brassica oleracea).
View Article and Find Full Text PDFUltrahigh-resolution NMR has recently attracted considerable attention in the field of complex samples analysis. Indeed, the implementation of broadband homonuclear decoupling techniques has allowed us to greatly simplify crowded H spectra, yielding singlets for almost every proton site from the analyzed molecules. Pure shift methods have notably shown to be particularly suitable for deciphering mixtures of metabolites in biological samples.
View Article and Find Full Text PDFDipolar or quadrupolar echoes allow one to observe undistorted powder patterns, in contrast to simple Fourier transformations of free induction decays (FIDs). In this work, the buildup of proton polarization due to dynamic nuclear polarization (DNP) is monitored by observing echoes rather than FIDs. When the microwave irradiation is interrupted during the buildup of DNP, the electrons relax back to their Boltzmann distribution at high fields ( = 6.
View Article and Find Full Text PDFBackground: Management of nonalcoholic steatohepatitis (NASH) is an unmet clinical need. Lanifibranor is a pan-PPAR (peroxisome proliferator-activated receptor) agonist that modulates key metabolic, inflammatory, and fibrogenic pathways in the pathogenesis of NASH.
Methods: In this phase 2b, double-blind, randomized, placebo-controlled trial, patients with noncirrhotic, highly active NASH were randomly assigned in a 1:1:1 ratio to receive 1200 mg or 800 mg of lanifibranor or placebo once daily for 24 weeks.
The 17O resonances of zirconium-oxo clusters that can be found in porous Zr carboxylate metal-organic frameworks (MOFs) have been investigated by magic-angle spinning (MAS) NMR spectroscopy enhanced by dynamic nuclear polarization (DNP). High-resolution 17O spectra at 0.037% natural abundance could be obtained in 48 hours, thanks to DNP enhancement of the 1H polarization by factors ε(1H) = Swith/Swithout = 28, followed by 1H → 17O cross-polarization, allowing a saving in experimental time by a factor of ca.
View Article and Find Full Text PDFPathogen pressure on hosts can lead to the evolution of genes regulating the innate immune response. By characterizing naturally occurring polymorphisms in immune receptors, we can better understand the molecular determinants of pathogen recognition. ZAR1 is an ancient Arabidopsis thaliana NLR (Nucleotide-binding [NB] Leucine-rich-repeat [LRR] Receptor) that recognizes multiple secreted effector proteins from the pathogenic bacteria Pseudomonas syringae and Xanthomonas campestris through its interaction with receptor-like cytoplasmic kinases (RLCKs).
View Article and Find Full Text PDFDynamic nuclear polarization of samples at low temperatures, typically between 1.2 and 4.2 K, allows one to achieve spin temperatures of as low as 2 mK so that for many nuclear isotopes the high-temperature approximation is violated for the nuclear Zeeman interaction.
View Article and Find Full Text PDFNLR (nucleotide-binding [NB] leucine-rich repeat [LRR] receptor) proteins are critical for inducing immune responses in response to pathogen proteins, and must be tightly modulated to prevent spurious activation in the absence of a pathogen. The ZAR1 NLR recognizes diverse effector proteins from Pseudomonas syringae, including HopZ1a, and Xanthomonas species. Receptor-like cytoplasmic kinases (RLCKs) such as ZED1, interact with ZAR1 and provide specificity for different effector proteins, such as HopZ1a.
View Article and Find Full Text PDFLong-lived imbalances of spin state populations can circumvent fast quadrupolar relaxation by reducing effective longitudinal relaxation rates by about an order of magnitude. This opens new avenues for the study of dynamic processes in deuterated molecules. Here we present an analysis of the relaxation properties of deuterated methyl groups CD.
View Article and Find Full Text PDFA novel system for dissolution dynamic nuclear polarization based on a cost-effective "cryogen-free" magnet that can generate fields up to 9.4 T with a sample space that can reach temperatures below 1.4 K in a continuous and stable manner.
View Article and Find Full Text PDFTailoring the physical features and the porous network architecture of silica-based hyperpolarizing solids containing TEMPO radicals, known as HYPSO (hybrid polarizing solids), enabled unprecedented performance of dissolution dynamic nuclear polarization (d-DNP). High polarization values up to P( H)=99 % were reached for samples impregnated with a mixture of H O/D O and loaded in a 6.7 T polarizer at temperatures around 1.
View Article and Find Full Text PDFThe advent of immune checkpoint blockers and targeted therapies has changed the outcome of melanoma. However, many patients experience relapses, emphasizing the need for predictive and prognostic biomarkers. We developed a strategy based on plasmacytoid dendritic cells (pDCs) loaded with melanoma tumor antigens that allows eliciting highly efficient antitumor T-cell responses.
View Article and Find Full Text PDF