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Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 157
Author(s):  
Ljubica Tasic ◽  
Nataša Avramović ◽  
Melissa Quintero ◽  
Danijela Stanisic ◽  
Lucas G. Martins ◽  
...  

Pediatric cancer NMR-metabonomics might be a powerful tool to discover modified biochemical pathways in tumor development, improve cancer diagnosis, and, consequently, treatment. Wilms tumor (WT) is the most common kidney tumor in young children whose genetic and epigenetic abnormalities lead to cell metabolism alterations, but, so far, investigation of metabolic pathways in WT is scarce. We aimed to explore the high-resolution magic-angle spinning nuclear magnetic resonance (HR-MAS NMR) metabonomics of WT and normal kidney (NK) samples. For this study, 14 WT and 7 NK tissue samples were obtained from the same patients and analyzed. One-dimensional and two-dimensional HR-MAS NMR spectra were processed, and the one-dimensional NMR data were analyzed using chemometrics. Chemometrics enabled us to elucidate the most significant differences between the tumor and normal tissues and to discover intrinsic metabolite alterations in WT. The metabolic differences in WT tissues were revealed by a validated PLS-DA applied on HR-MAS T2-edited 1H-NMR and were assigned to 16 metabolites, such as lipids, glucose, and branched-chain amino acids (BCAAs), among others. The WT compared to NK samples showed 13 metabolites with increased concentrations and 3 metabolites with decreased concentrations. The relative BCAA concentrations were decreased in the WT while lipids, lactate, and glutamine/glutamate showed increased levels. Sixteen tissue metabolites distinguish the analyzed WT samples and point to altered glycolysis, glutaminolysis, TCA cycle, and lipid and BCAA metabolism in WT. Significant variation in the concentrations of metabolites, such as glutamine/glutamate, lipids, lactate, and BCAAs, was observed in WT and opened up a perspective for their further study and clinical validation.


2022 ◽  
Author(s):  
Morgane Callon ◽  
Alexander A Malär ◽  
Lauriane Lecoq ◽  
Marie Dujardin ◽  
Marie-Laure Fogeron ◽  
...  

Experimentally determined protein structures often feature missing domains. One example is the C terminal domain (CTD) of the hepatitis B virus capsid protein, a functionally central part of this assembly, crucial in regulated nucleic-acid interactions, cellular trafficking, nuclear import, particle assembly and maturation. However, its structure remained elusive to all current techniques, including NMR. Here we show that the recently developed proton-detected fast magic-angle-spinning solid-state NMR at >100 kHz MAS is a game changer that allows to detect this domain and unveil its structural and dynamic behavior. We describe the experimental framework used and compare the domain’s behavior in different capsid states. The developed approaches extend solid-state NMR observations to residues characterized by large-amplitude motion on the microsecond timescale, and shall allow to shed light on other flexible protein domains still lacking their structural and dynamic characterization.


2022 ◽  
Vol 29 (1) ◽  
Author(s):  
Antonia S. Yorkshire ◽  
Martin C. Stennett ◽  
Brant Walkley ◽  
Sarah E. O'Sullivan ◽  
Lucy M. Mottram ◽  
...  

Portland cement based grouts used for radioactive waste immobilization contain high replacement levels of supplementary cementitious materials, including blast-furnace slag and fly ash. The minerals formed upon hydration of these cements may have capacity for binding actinide elements present in radioactive waste. In this work, the minerals ettringite (Ca6Al2(SO4)3(OH)12·26H2O) and hydrotalcite (Mg6Al2(OH)16CO3·4H2O) were selected to investigate the importance of minor cement hydrate phases in sequestering and immobilizing UVI from radioactive waste streams. U L III-edge X-ray absorption spectroscopy (XAS) was used to probe the UVI coordination environment in contact with these minerals. For the first time, solid-state 27Al magic angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopy was applied to probe the Al coordination environment in these UVI-contacted minerals and make inferences on the UVI coordination, in conjunction with the X-ray spectroscopy analyses. The U L III-edge XAS analysis of the UVI-contacted ettringite phases found them to be similar (>∼70%) to the uranyl oxyhydroxides present in a mixed becquerelite/metaschoepite mineral. Fitting of the EXAFS region, in combination with 27Al NMR analysis, indicated that a disordered Ca- or Al-bearing UVI secondary phase also formed. For the UVI-contacted hydrotalcite phases, the XAS and 27Al NMR data were interpreted as being similar to uranyl carbonate, that was likely Mg-containing.


2021 ◽  
Author(s):  
Zhengfeng Zhang ◽  
Yongchao Su ◽  
Jun Yang

Heteronuclear correlation (HETCOR) is critical to obtain structural information in solid-state nuclear magnetic resonance (NMR). We propose novel frequency-selective Heteronuclear correlation (FS-HETCOR) experiments to selectively enhance the inter-atomic correlations of interest. FS-HETCOR relies on heteronuclear selective phase-optimized recoupling (SPRx), which is frequency-selective in heteronuclear recouping without using selective pulses. Compared to regular HETCOR, FS-HETCOR selectively enhances the desired heteronuclear correlations by a factor of up to 5 and suppresses the unwanted ones to 10% as demonstrated in 1H-19F and 1H-13C experiments under fast magic-angle spinning (MAS). Moreover, FS-HETCOR can theoretically be applied at arbitrary MAS rates by utilizing various SPRx schemes. We believe that the method will enhance the ability of solid-state NMR to probe heteronuclear structural information.


2021 ◽  
Vol 8 ◽  
Author(s):  
Roman Zadorozhnyi ◽  
Sucharita Sarkar ◽  
Caitlin M. Quinn ◽  
Kaneil K. Zadrozny ◽  
Barbie K. Ganser-Pornillos ◽  
...  

Histidine residues play important structural and functional roles in proteins, such as serving as metal-binding ligands, mediating enzyme catalysis, and modulating proton channel activity. Many of these activities are modulated by the ionization state of the imidazole ring. Here we present a fast MAS NMR approach for the determination of protonation and tautomeric states of His at frequencies of 40–62 kHz. The experiments combine 1H detection with selective magnetization inversion techniques and transferred echo double resonance (TEDOR)–based filters, in 2D heteronuclear correlation experiments. We illustrate this approach using microcrystalline assemblies of HIV-1 CACTD-SP1 protein.


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