Multiple sclerosis (MS) is a T cell-mediated autoimmune disease modeled by experimental autoimmune encephalomyelitis (EAE); given that SPTLC2 is a key enzyme in sphingolipid biosynthesis linked to MS pathology, this NMR-based metabolomics study aimed to characterize the metabolic signature resulting from T cell-specific SPTLC2 conditional knock-out (KO) in EAE mice. Serum samples from unrecombined control EAE mice and T cell-specific SPTLC2 KO EAE mice were analyzed using OPLS-DA and the Mann-Whitney test (FDR < 0.05). Multivariate analysis revealed a complete and statistically robust separation between the two groups (OPLS-DA: R2Y = 0.902, Q2 = 0.899, p < 0.001), indicating a massive metabolic alteration induced by the T cell-specific SPTLC2 deletion. Univariate analysis and the S-Plot confirmed that core metabolites, including Lactate, Alanine, Glutamine, Pyruvate, Citrate, and Trimethylamine, were significantly upregulated in the T cell-specific SPTLC2 KO group, while Glucose and Phenylalanine were downregulated (FDR << 0.05). These findings collectively demonstrate that T cell-specific SPTLC2 deletion fundamentally disrupts central energy and amino acid metabolism in the EAE model, positioning this sphingolipid biosynthesis enzyme as a critical metabolic regulator of T cell function and autoimmune disease pathology.

A calix[4]pyrrole derivative (2) bearing two amidoinodole substituents at the diagonal meso positions was synthesized and its anion-binding properties were investigated by ¹H NMR spectroscopic analysis in CD₂Cl₂. In comparison to the parent calix[4]pyrrole (1), receptor 2, incorporating additional hydrogen-bond donor and acceptor sites, exhibited markedly enhanced binding affinities toward a series of anions (F^-, Cl^-, Br^-, I^-, HSO₄^-, and H₂PO₄^-). The introduction of amidoinodole groups significantly strengthened the anion-receptor interactions, as evidenced by substantial downfield shifts of the pyrrolic and indolic NH resonances upon anion addition. Notably, receptor 2 was found to bind H₂PO₄^- via a distinct binding mode compared to those observed for the parent calix[4]pyrrole (1) and for the other anions examined, suggesting a unique cooperative hydrogen-bonding network involving both the core pyrrolic NH units and the appended indole-amide moieties.

The CRISPR-Cas system employs RNA-guided endonucleases that recognize and cleave invading foreign nucleic acids. Phages produce anti-CRISPR proteins that inhibit target Cas proteins and facilitate subsequent infection. AcrIIC4 was identified from prophages of Haemophilus parainfluenza and potently inhibits type II-C Cas9. Previous crystal structures reported two distinct helical conformations of AcrIIC4. Here, we measured residual dipolar coupling constants of amide resonances to determine the conformational state of AcrIIC4 in solution. Our results unambiguously illustrate that AcrIIC4 forms a three-helical bundle in solution at neutral pH, which is maintained in the AcrIIC4-Cas9 complex. We also report the backbone resonance assignments of AcrIIC4.

Hsp90 is a dynamic chaperone protein whose ATP-driven conformational cycle plays critical roles in the maturation and regulation of client proteins. Due to its large size and multi-domain architecture, however, conventional structural methods provide only limited insight into its dynamic features and related functionalities. Recent advances in ¹⁹F NMR spectroscopy have enabled residue-specific and background-free monitoring of Hsp90 dynamics across multiple structural scales. This mini-review highlights three representative studies that employed ¹⁹F NMR to dissect Hsp90's mechanistic cycle. These studies demonstrate the unique power of 19F NMR to probe conformational populations, exchange kinetics, and allosteric regulation in large protein systems.

²⁹Si and ²⁷Al solid-state nuclear magnetic resonance (NMR) spectroscopy has been established as a powerful technique for investigating the network connectivity and coordination environments for diverse crystalline and amorphous silicate materials. Recently, zeolite-geopolymer composites, emerging as sustainable and functional construction materials, have garnered significant interest for their mechanical properties and adsorption capabilities. However, the coexistence of crystalline and amorphous phases, as well as complex Si-Al coordination environments, makes detailed structural characterization challenging. In this mini-review, recent applications of ²⁹Si and ²⁷Al solid-state NMR to zeolite-geopolymer composites are summarized, highlighting the isotopic chemical shift ranges of geopolymer gels in comparison with coexisting crystalline phases. Perspectives on future studies are also discussed.

Eleutherococcus sessiliflorus (Ogapi) is a medicinal plant widely used as a functional food material in East Asia. In this study, a ¹H nuclear magnetic resonance (NMR) based metabolomics was applied to characterize primary metabolite profiles of bark and fruit tissues. A total of 34 and 33 metabolites were identified in bark and fruit, respectively. Fruit exhibited a monosaccharide dominated profile with high levels of fructose and glucose, whereas bark was sucrose-rich and contained characteristic amino and phenolic metabolites such as arginine, proline, and chlorogenate. These profiles indicate functional differentiation, with fruits specialized for sugar-based carbon storage supporting growth and reproduction, while bark metabolism is oriented toward cellular signaling and stress-related defense. In addition, solvent-dependent analysis of fruit reflux extracts revealed that water extracts were enriched in organic acids (e.g., lactate and succinate), whereas ethanol extracts contained higher levels of sugars. Collectively, this study provides the first comprehensive primary metabolite profiles for E. sessiliflorus, offering a foundation for its functional evaluation and targeted utilization as a bioresource.

Solid-state nuclear magnetic resonance (NMR) spectroscopy is widely used to investigate the structure and dynamics of a broad range of materials. In the case of paramagnetic materials, interactions with unpaired electrons lead to markedly broadened NMR frequency ranges, increased linewidths, and shortened longitudinal relaxation times (T₁). These features necessitate experimental approaches and spectral interpretation strategies that differ from those used for diamagnetic systems. In this paper, we summarize key spectroscopic characteristics of paramagnetic materials in solid-state NMR and present several representative examples illustrating these phenomena.