We demonstrate the use of two-dimensional ((13)C,(13)C) double-quantum spectroscopy to detect molecular dynamics by solid-state NMR. Data collected on tyrosine-ethylester (TEE) are in line with previously determined ((1)H,(13)C) order parameters. Application of these experiments to microcrystalline ubiquitin reveals the presence of dynamics on millisecond or faster time scales and differences in local mobility depending on microcrystal preparation. In addition, solid-state NMR-based structure calculation indicates conformational variability of loop regions between different solid-phase ubiquitin preparations. Our data relate preparation-dependent changes observed in NMR spectral parameters such as chemical shifts and through-space correlations to differences in ubiquitin dynamics and conformation and suggest a prominent role of molecular mobility in microcrystalline ubiquitin.
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Dalton Trans
January 2025
Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, 48149 Münster, Germany.
The cadmium-rich intermetallic compounds RhCd ( = Ca, Sr, Y, La-Nd, Sm-Lu) were synthesized from the elements in sealed tantalum tubes. The elements were reacted in an induction furnace and the samples were post-annealed to increase phase purity and crystallinity. The RhCd phases crystallize with the cubic CeCrAl type structure, space group 3̄.
View Article and Find Full Text PDFJ Pharm Sci
January 2025
Drug Delivery and Disposition, KU Leuven, Department of Pharmaceutical and Pharmacological Sciences, Campus Gasthuisberg ON2, Herestraat 49 b921, 3000 Leuven, Belgium. Electronic address:
In order to evaluate the stability of an amorphous solid dispersion (ASD) it is crucial to be able to accurately determine whether the ASD components are homogeneously mixed or not. Several solid-state analysis techniques are at the disposal of the formulation scientist, such as for example modulated differential scanning calorimetry (mDSC) and solid-state nuclear magnetic resonance spectroscopy (ssNMR). ssNMR is a robust, versatile, and accurate analysis technique with a large number of application possibilities.
View Article and Find Full Text PDFInorg Chem
January 2025
Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany.
Heteroleptic An (An = U, Np) chlorido-ketoenaminate complexes of the type [AnCl(TFB-BuA)(THF)] ( type: , ; TFB-BuA = 4-(-butylamino)-1,1,1-trifluorobut-3-en-2-one) and the homoleptic Np heteroarylalkenolate complexes [Np(PyTFP)] (, PyTFP = 1-(pyridin-2-yl)-3,3,3-trifluoroprop-1-en-2-ol) and [Np(DMOTFP)] (, DMOTFP = 1-(4,5-dimethyloxazol-2-yl)-3,3,3-trifluoroprop-1-en-2-ol) were synthesized and characterized (SC-XRD, NMR, Vis-NIR, MS). While their solid-state structures compare well to those of their uranium analogues, the behavior in solution showed significant differences. The binding motif of the DMOTFP ligand in complex can change to form two different complex isomers, as seen by paramagnetic chemical shifts in NMR experiments.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Regensburg, Faculty of Chemistry and Pharmacy, Institute of Inorganic Chemistry, Universitätsstraße 31, D-93053, Regensburg, GERMANY.
Aminophosphates are the focus of research on prebiotic phosphorylation chemistry. Their bifunctional nature also makes them a powerful class of organocatalysts. However, the structural chemistry and dynamics of proton-binding in phosphorylation and organocatalytic mechanisms are still not fully understood.
View Article and Find Full Text PDFMisfolding and aggregation of proteins into amyloidogenic assemblies are key features of several metabolic and neurodegenerative diseases. Human insulin has long been known to form amyloid fibrils under various conditions, which affects its bioavailability and function. Clinically, insulin aggregation at recurrent injection sites poses a challenge for diabetic patients who rely on insulin therapy.
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