The hydration and hydrogen-bond topology of small water solvated molecules such as the naturally occurring organic osmolytes trimethylamine N-oxide (TMAO) and urea are under intense investigation. We aim at furthering the understanding of this complex hydration by combining experimental oxygen K-edge excitation spectra with results from spectra calculated via the Bethe-Salpeter equation based on structures obtained from ab initio molecular dynamics simulations. Comparison of experimental and calculated spectra allows us to extract detailed information about the immediate surrounding of the solute molecules in the solvated state. We quantify and localize the influence of the solute on the hydrogen bond network of the water solvent and find spectroscopic fingerprints of a clear directional asymmetry around TMAO with strong and local kosmotropic influence around TMAO's NO head group and slight chaotropic influence around the hydrophobic methyl groups. The influence of urea on the local water network is qualitatively similar to that of TMAO but weaker in magnitude. The strongest influence of both molecules on the shape of the oxygen K-edge spectra is found in the first hydration shells.
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http://dx.doi.org/10.1039/c9cp06785j | DOI Listing |
J Phys Chem B
December 2024
Chemical Institute, Kazan Federal University, Kremlevskaya 18, Kazan 420008, Russia.
Physiol Res
November 2024
Department of Physiology, Hebei Medical University, Shijiazhuang, China. Hebei Provincial Hospital of Chinese Medicine, Hebei University of Chinese Medicine, Shijiazhuang, China.
Trimethylamine N-oxide (TMAO), a bioactive metabolite of gut microbes, plays a pivotal role in the pathogenesis of kidney diseases by activating programmed cell death (PCD) pathways. However, whether trimethylamine (TMA) contributes to chronic kidney injury and which kind of PCD is involved in TMA-induced chronic kidney injury has not been previously evaluated. To observe the effect of TMA, male C57BL/6J mice were randomly divided into two groups: the Control group and the TMA group.
View Article and Find Full Text PDFJ Phys Chem B
November 2024
Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.
Interactions of the peptide substance P (SP) (RPKPQQFFGLM-NH) with trimethylamine -oxide (TMAO) were investigated by using cryo-ion mobility-mass spectrometry (cryo-IM-MS), variable-temperature (278-358 K) electrospray ionization (vT-ESI) MS, and molecular dynamics (MD) simulations. Cryo-IM-MS provides evidence that cold solutions containing SP and TMAO yield abundant hydrated SP dimer ions, but dimer formation is inhibited in solutions that also contain urea. In addition, we show that SP dimer formation at cold solution temperatures (<298 K) is favored when TMAO interacts with the hydrophobic C-terminus of SP and is subject to reduced entropic penalty when compared to warmer solution conditions (>298 K).
View Article and Find Full Text PDFPhys Chem Chem Phys
August 2024
Faculty of Food Technology and Biotechnology, University of Zagreb, Croatia.
In biomedical and biotechnological domains, liquid protein formulations are vital tools, offering versatility across various fields. However, maintaining protein stability in a liquid form presents challenges due to environmental factors, driving research to refine formulations for broader applications. In our recent study, we investigated the relationship between deep eutectic solvents (DESs) and the natural presence of osmolytes in specific combinations, showcasing the effectiveness of a bioinspired osmolyte-based DES in stabilizing a model protein.
View Article and Find Full Text PDFJ Phys Chem Lett
August 2024
Graduate School of Pharmacy, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
We examined the effects of trimethylamine -oxide (TMAO) and urea (known osmolytes) on the liquid-liquid phase separation (LLPS) of fused in sarcoma (FUS) and three FUS-LLPS states: LLPS states at atmospheric pressure with low- and high-salt concentrations and a re-entrant LLPS state above 2 kbar. Temperature- and pressure-scan turbidity measurements revealed that TMAO and urea contributed to stabilizing and destabilizing LLPS, respectively. These results can be attributed to the excluded volume effect of TMAO (preferential hydration) and preferential interaction of urea with proteins.
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