Protein biomarkers in biofluids are highly sensitive indicators of prodromal cognitive impairment yet remain limited for primary prevention. Lipids, essential to brain structure and function, offer untapped prognostic value. Here, we identify a lipidomic signature in serum from asymptomatic PSEN1-E280A mutation carriers aged 6-40 years, that differentiate carriers from non-carriers with an AUC 80-90%. Similarly, to symptomatic carriers (older 41 years; 93%) and sporadic AD cases (85%), using high-resolution mass spectrometry. Latent profile analysis revealed lipid-based signatures of dementia risk and resilience, shaped by genotype, sex, and APOE isoform, and supported by SIMOA protein biomarkers. Age-dependent dysregulation in sphingolipid and glycolipid metabolism was validated by enzymatic activity (TLC), glial phenotyping (flow cytometry), and gene expression (snRNAseq) in postmortem brain. Ganglioside clearance deficits emerged by age 6-12, followed by proinflammatory shifts from age 13 and p-tau217 elevation by age 20, with greater burden in females and APOE4 carriers. APOE3Ch individuals showed differential salvage pathways of ceramides and gangliosides. These findings position early lipid pathway dysregulation as a biological contributor to Alzheimers pathogenesis and a potential therapeutic target for primary prevention.

ABSTRACT A simple, sensitive and efficient ultra performance liquid chromatography–mass spectrometry (UPLC–MS/MS) method for simultaneous quantitative determination of olmesartan and hydrochlorothiazide in human plasma has been developed and validated. Using olmesartan-d4 and hydrochlorothiazide-13C-d2 as stable isotope-labeled internal standard (SIL-IS). Plasma samples were processed by protein precipitation. Separated on a ZORBAX Eclipse XDB-Phenyl column (150 mm × 4.6 mm, 5 μm) using a gradient elution with mobile phases methanol and 5 mM ammonium acetate. Detected by electrospray ionization (ESI) in negative ion mode of multiple reaction monitoring (MRM), mass transition ion pairs were m/z 445.1 → 149.0 for olmesartan, m/z 295.9 → 204.9 for hydrochlorothiazide, m/z 449.1 → 149.1 for olmesartan-d4, and m/z 301.0 → 272.0 for hydrochlorothiazide-13C-d2. Linear ranges were 10–2000 ng/mL for olmesartan and 1.5–300 ng/mL for hydrochlorothiazide. Mean recoveries of olmesartan, hydrochlorothiazide, olmesartan-d4, and hydrochlorothiazide-13C-d2 were 91.31%, 99.34%, 92.62%, and 98.61%, respectively. Our method was well validated in selectivity, carryover, lower limit of quantification (LLOQ), calibration curve, accuracy, precision, dilution effect, matrix effect (normal, hyperlipidemic, and hemolyzed matrices), stability, recovery, and IRS. It was successfully applied in a bioequivalence study of olmesartan medoxomil and hydrochlorothiazide tablets (20/12.5 mg) in healthy Chinese volunteers.

ABSTRACT Yi-Mai compound (YMHJ), a traditional Chinese medicine formulation, has demonstrated therapeutic efficacy against atherosclerosis (AS) in clinical observational studies. To elucidate its underlying pharmacological mechanisms, this investigation employed an integrated approach combining ultra-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC-ESI-MS/MS), network pharmacology analysis, and molecular docking validation. Through systematic chemical profiling, 2136 constituents were identified in YMHJ, with 33 prioritized as potential bioactive components using network pharmacology-based target prediction. Subsequent multiomics analysis revealed 67 disease-related targets and six hub genes (PPARG, PTGS2, STAT3, TLR4, TNF, and TP53) that exhibited critical regulatory roles in AS pathogenesis. Functional enrichment analysis further indicated that YMHJ modulates key atherogenic processes through regulation of lipid metabolism pathways, RAS signaling cascade, and inflammatory response networks. These findings were corroborated by molecular docking simulations, which confirmed direct binding interactions between the identified compounds and core therapeutic targets. This study provides a comprehensive mechanistic framework for the antiatherosclerotic effects of YMHJ, bridging traditional medicinal knowledge with systems pharmacology insights.

The proteasome is essential for protein degradation, but its complexity can be lost in vitro. Here, the authors use in-situ cross-linking mass spectrometry and structural modeling to reveal compartment-specific interactions and previously uncharted structural heterogeneity and dynamics.

This study shows how the NgBR subunit controls the activity of human cis-prenyltransferase, a key enzyme for protein glycosylation. Combined experimental and computational analyses expose the inter-subunit interface as an allosteric regulatory hub.

Symbiotic associations enable species to integrate complementary traits and adapt to novel environments. However, how the host and endosymbiont exchange nutrients remains poorly understood in most cases. Previously Paramecium bursaria cells were shown to reorganize lipid droplets to accommodate endosymbiotic Chlorella cells and interfering with lipid metabolism reduced the endosymbiont number. Here, we combined transcriptomics, lipidomics, imaging mass spectrometry, and stable-isotope tracing to investigate organic nutrient exchange in this symbiotic system. Our results reveal that endosymbiotic algae undergo extensive reprogramming of lipid metabolic pathways and accumulate markedly higher levels of triglycerides than free-living algae. Isotope-labeling experiments demonstrate that at least some of these lipids originate from the host, providing direct evidence for organic carbon transfer from Paramecium to its algal endosymbionts. Together, our results show that the establishment of symbiosis fundamentally reshapes algal lipid metabolism and uncover an unexpected host-to-symbiont lipid provisioning mechanism-opposite to the canonical direction of carbon flow observed in most photosynthetic symbioses. This work provides new insight into the metabolic principles that sustain and stabilize endosymbiotic partnerships.

Non-tailed phages remain an underexplored group in marine environments, as tailed phages have dominated sequence and culture collections. However, recent surveys indicate that non-tailed phages might be more abundant than tailed phages, and with different effects on microbial mortality and gene transfer. Here, we report the structural characterization of bacteriophage NO16, a non-tailed vibriophage, one of the simplest members of the Double Jelly Roll (DJR) lineage. Mass spectrometry analyses indicate that the virion is composed of at least nine different proteins. NO16 has a pseudoT = 21 capsid, similar to other phages in the lineage but differs in the organization of minor capsid proteins, mainly in terms of membrane-capsid contacts. The DJR major capsid protein GP19 is stabilized by a cation in the base as previously observed in corticovirus PM2, and by strong electrostatic interactions between monomers. Notably, localized reconstruction reveals a symmetry mismatch at the vertex, where two trimeric GP13 spikes are anchored to a pentamer of the penton base GP14. GP13 presents carbohydrate-binding modules and putative glycosylase activity, indicating implications for host entry. Finally, we use structural and functional predictions for NO16 non-structural proteins to propose a complete atlas of the NO16 infectious cycle.

Publication date: Available online 28 November 2025 Source: Analytica Chimica Acta Author(s): Ana Jano, Adrián Fuente-Ballesteros, M.Teresa Martín, Ana M. Ares, José Bernal

Publication date: Available online 28 November 2025 Source: Analytica Chimica Acta Author(s): Alleigh N. Couch, Christopher M. Zall, J.Tyler Davidson

We present the first application of a deuterated water metabolic labeling workflow coupled with data-independent acquisition (DIA) tandem mass spectrometry (MS/MS) for quantifying label enrichment in MS/MS to study protein turnover. The approach automates the turnover rate determination from combined precursor and fragment ions. The truncation of the observed isotope distributions of fragments is overcome by implementing an approach to determining the label enrichment from two mass isotopomers. The high redundancy of fragment ions provides a confident assessment for deuterium enrichment. The DIA approach provides increased proteome coverage and depth for quantifying protein turnover rates compared to the traditional data-dependent (DDA) approach. This novel approach is validated in a murine myotube model of muscle hypertrophy and atrophy through the treatment with insulin-like growth factor 1 (IGF-1) and dexamethasone (Dex), respectively.

Publication date: Available online 27 November 2025 Source: Journal of Proteomics Author(s): Michele Martins, Fábio César Sousa Nogueira, Magno Junqueira, Guillaume Nugue

Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00168

ABSTRACT Tannins are widespread specialized plant metabolites that contribute significantly to the polyphenol content of plant-based diets. Their effects on human and animal health vary depending on their structure, with potential benefits including antioxidative, antimicrobial, anthelmintic, and anticarcinogenic properties. Understanding tannin composition and quantity in plant products is essential, as their bioactivities are influenced by their functional groups. Mass spectrometry-based techniques excel in tannin analysis, offering both qualitative and quantitative insights. Combining ultrahigh-performance liquid chromatography with electrospray ionization and high-resolution and triple quadrupole mass analyzers is optimal for comprehensive tannin profiling. Such an approach enables precise analysis and helps predict tannin bioactivities. This review highlights the mass spectrometric analysis of proanthocyanidins and hydrolysable tannins, addressing ionization techniques, interpretation of multiply charged ions, characteristic fragmentations, and reaction monitoring. Applications related to tannin bioactivities are also briefly discussed, demonstrating the utility of mass spectrometry in tannin analysis in complex sample matrices.

Analytical ChemistryDOI: 10.1021/acs.analchem.5c05933

Analytical ChemistryDOI: 10.1021/acs.analchem.5c05032

Publication date: Available online 26 November 2025 Source: Journal of Chromatography A Author(s): Long Yuan

Intracellular bacterial pathogens deploy effector proteins to hijack host membranes by targeting specific lipids. Phosphoinositides are key eukaryotic signaling molecules that govern membrane identity and dynamics, making them powerful levers for microbial interference. However, the bacterial repertoire of phosphoinositide-binding effectors remains largely undefined. In this study, we systematically identified such proteins using an expression library of 241 Legionella pneumophila effectors. We applied a combination of lipid bead pulldowns, mass spectrometry, colocalization with phosphoinositide biosensors, and protein-lipid overlay assays, leading to the validation of 18 new phosphoinositide-binding effectors. Structural predictions revealed that these proteins share compact alpha-helical folds distinct from canonical eukaryotic lipid-binding domains. Guided by this structural signature, we performed a computational screen across L. pneumophila, Coxiella burnetii, and Burkholderia pseudomallei. This analysis identified 15 additional effectors, which were experimentally validated as phosphoinositide binders. Altogether, we report 33 previously unrecognized bacterial phosphoinositide-binding effectors. While their lipid-binding profiles were diverse, many effectors showed a preference for compartments enriched in phosphatidylinositol 3-phosphate. These findings expand the known diversity of lipid-binding effectors produced by intracellular pathogens, identify new structural modules bacteria use for phosphoinositide recognition, and broaden our understanding of how pathogens exploit phosphoinositide signaling to manipulate host membranes.

Publication date: Available online 27 November 2025 Source: Analytica Chimica Acta Author(s): Yaping Li, Emir Nazdrajić, Wei Zhou, Janusz Pawliszyn

Publication date: Available online 26 November 2025 Source: Journal of Mass Spectrometry and Advances in the Clinical Lab Author(s): Per Bengtson, Magnus Förnvik Jonsson

Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00167

Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00155

Journal of the American Society for Mass SpectrometryDOI: 10.1021/jasms.5c00260

Analytical ChemistryDOI: 10.1021/acs.analchem.5c04847

Current mass spectrometry techniques for reading information stored in polymers require one sequencing experiment per sub-sequence, making the process slow. Here, the authors accelerate the reading process by combining tandem mass spectrometry with ion mobility spectrometry.