bims-mascan Biomed News
on Mass spectrometry in cancer research
Issue of 2026–09–27
23 papers selected by
Giovanny Rodríguez Blanco, Uniklinikum Graz



  1. Methods Mol Biol. 2027 ;3059 167-173
      Proteomics, the large-scale study of proteins, enables the identification, quantification, and functional characterization of proteins, revealing post-translational modifications and protein interactions that are not apparent from transcriptomic data. Human organoids, which recapitulate the structural and functional complexity of native epithelial tissues, provide powerful tools to study disease mechanisms and personalize therapies. However, their culture poses challenges for efficient protein extraction and reproducible analysis. Here, we present a proteomics workflow optimized to maximize protein recovery from Matrigel-encased organoids. Samples were processed using S-Trap microcolumns to minimize losses, followed by liquid chromatography-mass spectrometry (LC-MS) in data-independent acquisition (DIA/SWATH-MS) mode for comprehensive, untargeted quantification. Library-free computational analysis using DIA-NN, combined with differential expression analysis, enabled sensitive detection of key proteins in intestinal organoids.
    Keywords:  Amica; DIA-NN; Intestinal organoids; Liquid chromatography–mass spectrometry; Protein quantification; Proteomics
    DOI:  https://doi.org/10.1007/978-1-0716-5412-5_12
  2. mSystems. 2026 Sep 24. e0083926
      3-Hydroxy N-acyl amides are bioactive lipids with reported anti-obesity and glucose-regulating effects, yet they are rarely detected in untargeted metabolomics studies because they are largely absent from existing spectral reference libraries. To address this gap, we synthesized an MS/MS spectral resource comprising 436 structurally diverse 3-hydroxy N-acyl amides, spanning 3- to 18-carbon chains with a wide range of amine headgroups, such as ornithine, valine, and dopamine. Using a synthesis-driven reverse metabolomics approach, we found 161,626 spectral matches across 54,744 publicly available files in untargeted metabolomics data sets, revealing widespread occurrences in biological samples, including human-derived specimens. Of these molecules detected through MS/MS spectral matching, 334 represent newly reported biological entities. We further confirmed their presence in human saliva, stool, and skin using retention time and ion mobility measurements. Frequent detection in microbial data sets and validation in communities of human-derived gut bacteria support microbial production. Several metabolites also showed altered abundance in individuals with diabetes mellitus, showing that this lipid class is modulated in human metabolic disease. Together, these findings establish 3-hydroxy N-acyl amides as a distinct and biologically relevant lipid class, and the accompanying MS/MS spectral resource will enable their broader recognition and study in untargeted metabolomics data.
    IMPORTANCE: Microbe-host interactions lead to the production of metabolites that play an important role in human health and disease, though the annotation of such metabolites remains scarce. We created a re-usable MS/MS spectral library of an underrepresented class of compounds-3-hydroxy N-acyl amides. Our study characterized the presence of over 400 3-hydroxy N-acyl amides among thousands of public untargeted metabolomics datasets. We found over 100,000 instances of these metabolites within microbial, plant, and animal data, and used orthogonal validation methods to confirm nine previously unreported molecules within human feces, saliva, and skin samples. We cultured communities of human-derived gut bacteria and found evidence of bacterial production of four 3-hydroxy N-acyl amides. Our results suggest that these metabolites play important roles in human metabolism and disease, and sharing this curated resource enables the detection of these metabolites in future studies.
    Keywords:  diabetes; ion mobility; mass spectrometry; microbial metabolism; reverse metabolomics
    DOI:  https://doi.org/10.1128/msystems.00839-26
  3. J Proteomics. 2026 Sep 19. pii: S1874-3919(26)00138-7. [Epub ahead of print] 105735
      Plasma proteomics holds promise for biomarker discovery, yet its characterization remains limited by the complex dynamic range of protein concentrations. We benchmarked seven proteomics workflows including five MS-based strategies (NEAT, PCA-N, TOP14, ENRICH-iST, SEER) on the Orbitrap Astral and Exploris 480, and Olink Target Inflammation and Reveal on 80 lithium heparin plasma samples from two clinical cohorts. Workflows were evaluated for proteome depth, reproducibility, HPPP catalogue coverage and recovery of aging-associated biological signatures. The Astral outperformed the Exploris 480 three-fold in protein identifications at four-fold higher throughput. Proteome coverage ranged from 1159 (NEAT) to 6003 protein groups (SEER), the latter providing over 70% HPPP coverage. TOP14 and ENRICH-iST achieved intermediate depth with high reproducibility. ENRICH-iST further demonstrated applicability to lithium heparin plasma via a simple protocol adaptation. Both Olink assays quantified their complete target panels, capturing low-abundance markers partially inaccessible to MS. Despite limited numerical overlap between MS and Olink datasets, fold-change directionality was broadly concordant. SEER and Olink Reveal uniquely recovered aging-related pathway signatures, including telomere maintenance and immune modulation. No single workflow provides exhaustive plasma proteome coverage. Integration of MS and affinity-based assays should be considered in plasma biomarker research for comprehensive coverage of the plasma proteome. SIGNIFICANCE: Plasma proteomics is central to biomarker discovery and translational research, yet practical adoption of next-generation workflows is hampered by the absence of head-to-head data comparing both mass-spectrometry and affinity platforms on the same clinical samples. Plasma proteomics is central to biomarker discovery and translational research, owing to the accessibility of plasma and its capacity to reflect physiological and pathological processes across tissues. Despite major technological advances in both mass spectrometry-based and affinity-based proteomics, the practical adoption of these innovations in clinical and population-scale studies remains constrained by methodological heterogeneity and the absence of comprehensive comparative frameworks. As a result, study design and platform selection are often driven by technical availability rather than by an informed assessment of analytical trade-offs and biological objectives. To address this gap, we benchmarked seven workflows including five MS-based strategies (NEAT, TOP14 depletion, ENRICH-iST, PCA-N, and Seer Proteograph XT) and two affinity assays (Olink Target Inflammation and the newly released Olink Reveal) on 80 individual lithium-heparin plasma samples from two clinical cohorts, for a total of 1525 injections. To our knowledge, this is the first study to include Olink Reveal in a systematic cross-platform comparison and to directly compare the Orbitrap Astral with the previous-generation Orbitrap Exploris 480 under identical conditions. In our hands, the Astral delivered ~2.5-fold more identifications than the Exploris, and Seer on the Astral reached 6003 proteins (~70% of the HPPP catalogue) at near-complete albumin removal. No single protein was detected by every MS and Olink platform simultaneously, and only the deepest workflows (Seer and Olink Reveal) recovered aging-relevant pathways in a centenarian vs. adult comparison, showing that analytical depth directly determines biological interpretability. We further demonstrate that Olink Reveal can be fully automated on the Firefly System (R2 = 0.958 vs. manual preparation), enabling the throughput required for large clinical cohorts. Together, these results provide a concrete, evidence-based framework for workflow selection and support the co-deployment of deep MS and high-plex affinity assays as a comprehensive plasma-proteome-profiling strategy for clinical and translational proteomics. In this context, the present work provides a systematic and integrated benchmarking of multiple contemporary plasma proteomics workflows evaluated on a clinically relevant cohort. By comparing advanced mass spectrometry strategies and high-plex affinity-based assays under harmonized analytical conditions, this study goes beyond isolated performance metrics to examine how depth of coverage, reproducibility, throughput, and platform-specific biases influence biological interpretation. Importantly, the results demonstrate that no single workflow achieves exhaustive characterization of the plasma proteome, and that methodological choices directly shape the spectrum of detectable biological signals. The demonstrated complementarity between deep, discovery-oriented mass spectrometry workflows and highly standardized affinity-based platforms has direct implications for clinical implementation. While deep MS approaches maximize proteome coverage and enable hypothesis-generating analyses, affinity-based assays provide robust, scalable, and reproducible quantification of targeted low-abundance proteins that are often of primary clinical interest. In this study, the successful automation of the Olink Reveal workflow further illustrates how affinity-based proteomics can be adapted to high-throughput, standardized pipelines, an essential requirement for large clinical cohorts and longitudinal studies. This automation step reinforces the suitability of such platforms for routine deployment, while maintaining analytical consistency and quantitative reliability. From a clinical and translational perspective, this benchmark offers a reference framework to guide the rational selection and combination of plasma proteomics workflows according to study scale, sample availability, and intended downstream applications. By clarifying the strengths and limitations of each approach, this work contributes to improving experimental design, facilitating cross-study comparability, and supporting the gradual standardization required for clinical adoption. In the longer term, these results lay the groundwork for integrative analytical pipelines and harmonized data generation strategies that may enhance the reliability and interpretability of plasma proteomics in biomarker validation, longitudinal monitoring, and future clinical research settings.
    Keywords:  Affinity-based proteomics; Clinical samples; Mass spectrometry; Plasma; Proteomics
    DOI:  https://doi.org/10.1016/j.jprot.2026.105735
  4. Metabolomics. 2026 Sep 25. pii: 160. [Epub ahead of print]22(5):
       INTRODUCTION: Targeted metabolic phenotyping by liquid chromatography-tandem mass spectrometry (LC-MS/MS) relies on a fragmented toolchain of proprietary vendor formats, manual integration steps, and ad hoc quality-control (QC) scripts, introducing user- and laboratory-level variation that undermines reproducibility and confounds cross-laboratory and retrospective comparison.
    OBJECTIVES: To provide an open-source, R-native workflow for targeted multiple reaction monitoring (MRM/SRM) mass spectrometry data that consolidates vendor file conversion, peak integration, and QC reporting into a single reproducible pipeline while preserving auditable, human-in-the-loop peak review.
    METHODS: MStargetR builds on msConvert and Skyline through three modules: msConvertR (vendor-to-mzML conversion), PeakForgeR (peak boundary optimisation and automated peak integration executed through Skyline), and qcCheckR (normalisation, concentration calculation, signal and batch correction, and reporting). Additionally, MStargetR has a standalone correction module and a Shiny graphical user interface. Third-party tools are pinned in version-controlled Docker images (with Apptainer support for high-performance computing), and each analytical plate emits a fully populated sky document for inspection and reimport.
    RESULTS: Applied to a published targeted lipidomics dataset of 128 human plasma samples targeting 1,161 lipid species, MStargetR processed all samples end-to-end, recovering all 1,161 targeted lipid features, 949 of which (81.7%) were detected and returned RSD < 30% across replicated long-term reference QCs. Analysis scaled linearly to 4,200 samples, averaging 4.1 s per sample.
    CONCLUSION: MStargetR delivers automated batch processing, auditable peak review, and a documented QC layer in a single reproducible pipeline, supporting FAIR-aligned targeted metabolomics.
    Keywords:  Lipidomics; Mass spectrometry; Multiple reaction monitoring; Phenotype; Precision medicine; Reproducibility of results; Software
    DOI:  https://doi.org/10.1007/s11306-026-02541-2
  5. Anal Chim Acta. 2026 Nov 08. pii: S0003-2670(26)01037-8. [Epub ahead of print]1422 346087
      Recently, feces has gained increased attention in metabolomics and lipidomics research due to its ability to reflect complex diet-host-microbiome interactions. Traditionally, these analyses rely on separate workflows, resulting in longer analysis times and increased instrument load. To address these limitations, we present a dual ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (dual UHPLC-HRMS) approach. As a first step, two previously validated single UHPLC-HRMS methods for metabolomics and lipidomics, each demonstrating robust chromatographic separation of compounds, covering a broad physicochemical range (LogP -5.30 to 21.90), were selected. To integrate both workflows into the dual platform, thirteen critical LC-MS parameters were systematically optimized using a Design of Experiments (DoE). The parameters encompassed ion generation, transmission and detection, injection-related factors, unified column oven conditions, and source geometry. This approach enabled a robust dual workflow, achieving a 21% reduction in analysis time. Targeted evaluation demonstrated consistent detection of 287 metabolites (260 with CV<20%) and 162 lipids (144 with CV<20%), thereby outperforming the single methods, which detected 272 metabolites (232 with CV<20%) and 145 lipids (116 with CV<20%), respectively. Untargeted analysis further demonstrated increased coverage, with an additional 1652 metabolite and 3966 lipid features detected with the dual method without compromising repeatability of the feature signal intensities (79.4% vs. 81.2% for metabolomics and 87.4% vs. 82.7% for lipidomics, with CV<30%). Our novel dual UHPLC-HRMS workflow enhances analytical throughput, while also improving fecal metabolome and lipidome coverage and repeatability, offering a robust and cost-effective solution for large-scale studies.
    Keywords:  Analytical method development; Gut phenotyping; Integrated multi-omics; Small molecules; Statistical design; Stool
    DOI:  https://doi.org/10.1016/j.aca.2026.346087
  6. J Chromatogr B Analyt Technol Biomed Life Sci. 2026 Sep 19. pii: S1570-0232(26)00393-4. [Epub ahead of print]1284 125304
      Untargeted lipidomics enables comprehensive characterization of lipid profiles; however, analytical variability in sample preparation, chromatographic conditions, and data processing often limits reproducibility. Thus, this study aimed to optimize untargeted lipidomics analysis by evaluating chromatographic columns, mobile-phase additives, and lipid extraction methods to maximize feature detection, reproducibility, and overall data quality. Chromatographic performance was compared between ethylene-bridged hybrid (BEH) and charged-surface hybrid columns. For mobile-phase additives, 10 mM ammonium formate (AmFa) with or without 0.1% formic acid (Fa) was evaluated in positive ionization mode, whereas 10 mM ammonium acetate (AmAc) with or without 0.1% acetic acid was evaluated in negative ionization mode. Lipid extraction was assessed using chloroform-, methyl tert-butyl ether-, or butanol-based methods, with or without re-extraction. The final optimized workflow consisted of a BEH column, 10 mM AmFa with 0.1% Fa in positive mode, 10 mM AmAc in negative mode, and the Folch extraction method. The optimal analytics applied to plasma samples collected from women with primary dysmenorrhea, before and after Dangguijakyak-San (DJS) administration, identifying 321 lipid species across major classes, including glycerophospholipids, glycerolipids, and sphingolipids. Principal component analysis of quality control samples demonstrated tight clustering, and 14 internal standards exhibited relative standard deviations below 30%, confirming analytical robustness. Four lipid species were significantly altered: three phosphatidylcholines decreased, and one ceramide phosphoinositol increased after DJS administration. These alterations suggest modulation of oxidative stress-related lipid pathways and sphingolipid metabolism. This optimized analytical workflow provides reproducible plasma lipidomics and has potential applications in studies of traditional herbal medicines.
    Keywords:  Analytics optimization; Human plasma; UHPLC–QTOF/MS; Untargeted lipidomics
    DOI:  https://doi.org/10.1016/j.jchromb.2026.125304
  7. Electrophoresis. 2026 Sep 23.
      Low-input mass spectrometry (MS)-based proteomics is vulnerable to peptide loss during final sample preparation. We evaluated whether ChocoTip desalting and decyl maltose neopentyl glycol (DMNG)-assisted reconstitution improve peptide recovery from HeLa digests corresponding to 10 ng of protein (∼50 cells). ChocoTip reduces irreversible peptide adsorption into mesopores of chromatographic particles during microscale desalting, whereas DMNG is expected to suppress hydrophobic-interaction-mediated nonspecific adsorption to plasticware during redissolution, transfer, and injection. After selecting DMNG as the nonionic detergent additive, we compared conventional StageTip desalting, ChocoTip desalting, DMNG-assisted reconstitution, and their combination. ChocoTip and DMNG method each improved peptide recovery but affected the peptide populations eluting in different regions of the nanoflow reversed-phase liquid chromatography (nanoRPLC) gradient. Their combination yielded the highest number of peptide identifications and increased peptide intensities across almost the entire nanoRPLC gradient, including commonly identified peptides. Peptides uniquely recovered by the combined workflow covered a broad hydrophobicity range and included longer sequences. These results indicate that suppressing peptide loss at both desalting and post-desalting stages provides a simple strategy to improve sensitivity and peptide coverage in low-input MS-based proteomics.
    Keywords:  StageTip; irreversible adsorption; low‐input proteomics; nonionic detergent; nonspecific adsorption; sample preparation
    DOI:  https://doi.org/10.1002/elps.70161
  8. Anal Sci Adv. 2026 Dec;7(2): e70111
      Quantitative multi-target analysis of biological samples using isotope-dilution liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is widely applied in laboratory diagnostics and life sciences now. These analyses generate a large amount of metadata (e.g. ion ratios, peak width, etc.) that must be reviewed before results can be released. Until now, these complex and time-consuming tasks are performed mainly by technicians without dedicated software support. To explore whether practical tools for supporting result validation and release can be developed using standard spreadsheet software. A script, named MS Excel-based evaluation macro (MSVal), was developed in Microsoft Excel. Data sets from the quantification software of an LC-MS/MS system are imported into this tool. Validation criteria as quality assurance rules for analytical series and individual samples are defined within MSVal. The tool's functionality was evaluated using datasets from cystic fibrosis transmembrane conductance regulator (CFTR)-modulator therapeutic drug monitoring (TDM) analytical series. After importing raw MS data, MSVal generates a list of results that meet predefined validation criteria. MSVal also produces a validation report for each analytical series. Results that do not meet validation criteria are highlighted and must be specifically addressed by the operator during the release process. MSVal was successfully tested with real-world datasets. The development of software applications to support validation and result release in quantitative isotope-dilution LC-MS/MS analysis is feasible using standard software. Further refinement and progression toward commercial solutions appear valuable to close a significant gap in the clinical application of mass spectrometry.
    Keywords:  LC‐MS/MS; data management; metadata; peak review; quality assurance; result release
    DOI:  https://doi.org/10.1002/ansa.70111
  9. Expert Rev Proteomics. 2026 Sep 23.
       INTRODUCTION: Proteomics has become a data-rich discipline, supported by high-throughput mass spectrometry (MS), public repositories, community standards, and increasingly scalable computational workflows. However, the public availability of proteomics datasets does not guarantee that they can be reanalyzed, compared with other studies, integrated with other omics layers, or used to support clinical interpretation.
    AREAS COVERED: This review addresses the standards, infrastructures, and analytical practices required to make proteomics reusable beyond the initial publication. We discuss the differences between data deposition, the FAIR (Findable, Accessible, Interoperable, and Reusable) principles, interoperability, and true reusability, and assess the roles of repositories, workflow-level reproducibility, multi-omics integration, and clinical phenotype harmonization. Common points of failure are highlighted: gaps in metadata, tool-specific outputs, misuse of missing values, batch-effect overcorrection, proteoform collapse, and premature claims of AI-readiness.
    EXPERT OPINION: From data sharing as a final reporting obligation to interoperability as a design principle. Reusable-by-design proteomics requires that biospecimen context, metadata, spectral evidence, protein inference, quality control, workflow provenance, molecular specificity, and clinical meaning are all planned in concert from the outset of a study. The future impact of proteomics will depend not only on generating more data, but also on making those data independently interpretable, computable, auditable, and clinically reusable. For candidate medical tests, reusable-by-design should additionally anticipate metrological traceability, fit-for-purpose measurement uncertainty, and intended-use-specific analytical and clinical evidence so that clinically interpreted results remain comparable across laboratories, platforms, and time.
    Keywords:  FAIR data; HUPO-PSI; ProForma; ProteomeXchange; Proteomics; SDRF-Proteomics; clinical biomarker development; clinical proteomics; data integration; multi-omics; mzML; mztab
    DOI:  https://doi.org/10.1080/14789450.2026.2738952
  10. Metabolites. 2026 Aug 29. pii: 630. [Epub ahead of print]16(9):
       BACKGROUND: Atrial fibrillation (AF) is the most prevalent clinical arrhythmia with severe cardiovascular complications, yet its metabolic molecular mechanisms remain poorly defined. Omics-based metabolic profiling provides a powerful strategy to systematically decode AF-associated metabolic disorders.
    METHODS: In this work, high-coverage targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics and lipidomics were applied to absolutely quantify 746 serum metabolites from AF patients and healthy controls.
    RESULTS: We systematically characterized global metabolic perturbations in AF serum, including impaired fatty acid metabolism, suppressed mitochondrial β-oxidation, myocardial lipotoxic lipid accumulation, and systemic depletion of glycerophospholipids. Global multiscale embedded correlation network analysis (MECNA) further identified 11 AF-specific dysregulated metabolic modules and core hub metabolites driving metabolic remodeling. Leveraging binary logistic regression, we constructed and independently validated a two-molecule diagnostic biomarker panel to distinguish AF patients from healthy subjects. The combined biomarkers Phe-Trp and FA 22:5 achieved outstanding diagnostic performance, with area under the curve (AUC) values of 0.964 in the discovery cohort and 0.993 in the validation cohort.
    CONCLUSIONS: Collectively, this study adopts high-depth targeted quantitative omics to comprehensively map AF metabolic signatures, dissect disease-relevant metabolic networks, and establish a robust serum biomarker panel with great translational potential for non-invasive AF clinical diagnosis.
    Keywords:  atrial fibrillation; lipidomics; metabolic network; metabolomics; serum biomarker
    DOI:  https://doi.org/10.3390/metabo16090630
  11. Nat Protoc. 2026 Sep 24.
      Super-resolution structured illumination microscopy (SIM) is a powerful and versatile technique for investigating fundamental cell biological processes underlying development and disease. With the growing availability of commercial SIM systems, the emergence of advanced SIM modalities and increased access through imaging facilities, adoption of SIM across research laboratories is accelerating. However, fully leveraging the capabilities of SIM remains challenging, even for experienced microscopists, due to its susceptibility to imaging artifacts and the limited availability of accessible analysis pipelines. Here, to address these challenges, we developed SIMworks, a broadly compatible, integrated software platform designed to streamline quality control, processing and quantitative analysis of large-scale SIM datasets. Building on our previously established tools-SIMcheck, Chromagnon, ChaiN and SIMinspector-SIMworks provides a unified framework compatible with both custom and commercial SIM systems and modalities. Its modular architecture includes tools for calibration, alignment and data processing, as well as robust artifact detection and correction. These are complemented by segmentation and quantification modules for a broad range of cellular and nuclear structures, enabling automated, intensity-based analysis. Each module includes detailed guidance on interpretation and troubleshooting to support usability and reproducibility, enabling both new learners and experienced users to apply best practices in SIM imaging. The complete workflow can be performed within approximately half a day, depending on dataset size and complexity. SIMworks represents the first comprehensive, modular solution for SIM data processing, augmentation and quantitative analysis, lowering technical barriers and enhancing data reliability. By facilitating rigorous workflows, SIMworks promotes the broader integration of quantitative SIM imaging into biomedical research.
    DOI:  https://doi.org/10.1038/s41596-026-01444-9
  12. bioRxiv. 2026 Sep 15. pii: 2026.09.09.750520. [Epub ahead of print]
      Characterizing proteome complexity in disease contexts is essential for understanding molecular mechanisms and advancing therapeutic development. Mass spectrometry (MS)-based top-down and middle-down proteomics (TDP/MDP) can resolve intact proteoforms - protein molecules carrying a unique combination of isoform sequence and post-translational modifications (PTMs); however, their technical complexity and modest throughput present challenges for experimental planning and limit their broader application. Here, we present ProteoformTracker, an online web tool that prospectively models MS signal and evaluates the feasibility of using TDP/MDP to distinguish a target proteoform from related isoforms and the background proteome. ProteoformTracker takes as input a gene's annotated isoforms, a novel long-read/assembled transcript, or an rMATS alternative-splicing event, with or without user-specified PTMs, and predicts each proteoform's MS1 charge-state envelope and exact isotope pattern, scores per-bond MS2 fragmentation propensity, and searches the full reference human proteome for confounding proteins that could share the target's intact mass or a charge-state m/z peak. ProteoformTracker also supports middle-down workflows via simulated partial protease digestion. Results are rendered as interactive, zoomable MS1 and MS2 visualizations with live resolvability and fragment-ion statistics, letting users incorporate outside evidence into which confounders they compare against. We envision ProteoformTracker as a useful tool for users to plan TDP/MDP experiments targeting specific proteoforms.
    DOI:  https://doi.org/10.64898/2026.09.09.750520
  13. RSC Chem Biol. 2026 Sep 10.
      Targeting E3 ubiquitin ligases with chemical probes remains a major challenge, despite their central roles in cellular regulation and disease. Constitutive photomorphogenic 1 (COP1) is an E3 ligase whose complex, adaptor-dependent biology has made its selective targeting difficult. Here, we develop a peptide-based affinity selection mass spectrometry (Pep-AS-MS) platform to discover new peptide based COP1 binders. Leveraging a mass spectrometry compatible library design, fluorescence-guided selection optimisation, and an open-source software driven target-decoy database strategy for peptide identification and quantification, we enable hit ranking from highly complex combinatorial libraries. Using this approach, we identify and validate six previously unreported COP1-binding peptides, including ligands with binding potencies comparable to the native TRIB1 motif. This work establishes a quantitative and accessible Pep-AS-MS framework for ligand discovery against challenging protein-protein interaction targets and provides new chemical tools to interrogate COP1 biology.
    DOI:  https://doi.org/10.1039/d6cb00250a
  14. Anal Chim Acta. 2026 Nov 08. pii: S0003-2670(26)01062-7. [Epub ahead of print]1422 346112
      Stable isotope analysis of nitrogen (N) at natural abundance provides key insights into biochemical processes. However, position-specific isotope analysis (PSIA) of 15N remains technically challenging due to the low sensitivity of conventional approaches. The approach we present here relies on resolving the 1H-15N doublets embedded within dominant 1H-14N triplets and quantifying them via spectral deconvolution under rigorously optimized quantitative NMR conditions. Using ammonium chloride as a model, we established the experimental and processing parameters required for precision (≤2‰) and trueness (<3‰), validated against isotope ratio monitoring Mass Spectrometry (irm-MS). The method was successfully extended to structurally more complex compounds (aniline, indole, urea, and N-acetylated tryptophan methyl ester), achieving accurate position-specific δ15N determinations. Importantly, we demonstrate the feasibility of applying this strategy to a human urine sample, enabling direct δ15N measurement of endogenous urea in a complex biological matrix at natural abundance. This non-destructive method requires minimal sample amounts and offers a robust complement to irm-MS, expanding the analytical toolbox for nitrogen isotope research in environmental, biochemical, and biomedical contexts.
    Keywords:  (1)H NMR; Natural abundance; Nitrogen isotope; Position specific isotope analysis
    DOI:  https://doi.org/10.1016/j.aca.2026.346112
  15. bioRxiv. 2026 Sep 17. pii: 2026.09.15.751849. [Epub ahead of print]
      Adipocyte signaling adaptively responds to macronutrients, but how essential micronutrients impact lipid homeostasis remains poorly understood. Here, we demonstrate that folate polyglutamylation, the sequential conjugation of glutamate residues to folate, serves as a dynamic biochemical process regulating metabolic signaling. Using our folate metabolomics platform, we show that polyglutamylated folic acid accumulates in healthy adipose tissue, but is depleted in obesity across mice and humans, independent of circulating folate levels. Genetic ablation of the polyglutamylation enzyme folylpolyglutamate synthase (Fpgs) in adipocytes suppresses lipid catabolism to induce cell-autonomous lipid accumulation, operating independently of canonical adipogenesis or downstream one-carbon flux. Target-engagement proteomics identifies monoglutamylated folic acid as a Map2k5-interacting molecule that inhibits Map2k5 activity, whereas Fpgs-mediated folic acid polyglutamylation acts as a chemical switch that disrupts this interaction to promote lipolysis. In vivo , whole-body inhibition of Map2k5 or adipose-targeted genetic depletion of Fpgs increases body fat mass in the absence of dietary obesogenic triggers. Furthermore, single-cell and single-nuclear transcriptomic analyses establish the Fpgs-Map2k5 pathway as a core transcriptional signature of mouse and human adipose tissues. These findings uncover a non-canonical signaling role for folate that regulates adipocyte lipid homeostasis.
    DOI:  https://doi.org/10.64898/2026.09.15.751849
  16. Biochim Biophys Acta Proteins Proteom. 2026 Sep 22. pii: S1570-9639(26)00057-9. [Epub ahead of print] 141180
      Proteomics has evolved from a predominantly mass spectrometry (MS)-based discipline into a broader analytical field that includes complementary affinity-based technologies for large-scale protein characterization. MS remains the cornerstone of modern proteomics because it enables unbiased identification and quantification of proteins, post-translational modifications, and proteoforms. The need for high-throughput, low-input, and scalable protein profiling has nevertheless accelerated the adoption of SomaScan, Olink Proximity Extension Assay (PEA), and emerging single-molecule platforms such as Nautilus Voyager™. Although all use affinity recognition, they interrogate different molecular features aptamer-binding surfaces, paired antibody epitopes, or cumulative binding patterns used to infer intact-protein identity and should therefore be viewed as complementary rather than interchangeable. This review summarizes the evolution, principles, workflows, strengths, limitations, and representative applications of MS, SomaScan, Olink PEA, and Nautilus Voyager, and discusses their integration in biomarker discovery, population proteomics, and precision medicine. Emerging opportunities in artificial intelligence, single-cell and spatial proteomics, multi-omics integration, and next-generation affinity reagents are also considered.
    Keywords:  Affinity-based proteomics; Artificial intelligence; Biomarker discovery; Mass spectrometry; Multi-omics integration; Nautilus voyager; Olink proximity extension assay; Precision medicine; Proteomics; Single-cell proteomics; SomaScan; Spatial proteomics
    DOI:  https://doi.org/10.1016/j.bbapap.2026.141180
  17. Metabolites. 2026 Sep 07. pii: 654. [Epub ahead of print]16(9):
      Small biomolecules provide important information on cellular metabolism, signaling and disease-associated molecular changes. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) enables rapid, high-throughput and spatially resolved molecular analysis, but its application to small biomolecules is often limited by poor ionization, low-mass background interference, ion suppression and insufficient structural information. To address these analytical challenges, this review summarizes chemical derivatization strategies that improve MALDI-MS analysis of small biomolecules. The representative strategies are discussed according to reaction mode and target functional group, including solution-phase, on-target, on-tissue, reactive-matrix-assisted and photo-/in-source approaches, with emphasis on amine-, carbonyl-, carboxyl- and double-bond-containing biomolecules. Chemical derivatization improves MALDI-MS performance by selectively modifying target functional groups, introducing charged or ionizable tags, enhancing molecular discrimination and providing additional structural information. These strategies have expanded the detection and annotation of neuroactive amines, carbonyl compounds, glycans, carboxylic acid metabolites and lipid double-bond isomers, while also extending MALDI-MS analysis to other specific functional groups, natural products and drug-related molecules. Overall, chemical derivatization is an important approach for improving the sensitivity, selectivity, structural annotation and analytical coverage of MALDI-MS-based small biomolecule analysis. Future developments should further address reaction selectivity, spatial fidelity, quantitative reliability and confident identification of derivatization products.
    Keywords:  MALDI-MS; biomolecules; chemical derivatization; spatial metabolomics
    DOI:  https://doi.org/10.3390/metabo16090654
  18. bioRxiv. 2026 Sep 14. pii: 2026.09.13.750663. [Epub ahead of print]
      Proliferating cells must acquire nucleotides to support DNA replication, yet how cells meet these nucleotide demands for proliferation under physiological conditions remains understudied. Here, we investigated how physiological nutrient availability shapes nucleotide acquisition strategies in a mouse model of B-cell acute lymphoblastic leukemia (B-ALL). To assess how environmental nutrients impact nucleotide metabolism, we formulated a mouse plasma-like medium (MPM) that reproduces the circulating metabolite composition of plasma from mice with B-ALL and assessed how this influenced nucleotide metabolism relative to standard culture conditions, where nucleotide acquisition has historically been studied. We find that leukemia cells cultured in MPM acquire nucleotides through salvage pathways, and that select nucleotide salvage pathways are required for proliferation under physiological conditions. Of note, this dependency on nucleotide salvage in plasma-like conditions was not caused by precursor metabolite limitation for de novo synthesis. Instead, we found that physiological folate levels are insufficient to support deoxynucleotide triphosphate (dNTP) synthesis for genome replication, leading to DNA replication stress and impaired proliferation when nucleotide salvage is disrupted. Consistently, dietary folate restriction exacerbates the impaired leukemia progression phenotype of nucleotide salvage-deficient B-ALL cells. Together, these findings demonstrate that access to folates is an endogenous limitation for nucleotide synthesis in plasma-like nutrient conditions, increasing the relevance of nucleotide salvage pathways for leukemia progression. More broadly, this work highlights how micronutrient abundance can influence metabolic dependencies and reveals that folate levels shape nucleotide metabolism under physiological conditions.
    DOI:  https://doi.org/10.64898/2026.09.13.750663
  19. STAR Protoc. 2026 Sep 23. pii: S2666-1667(26)00506-X. [Epub ahead of print]7(4): 104853
      Quantitative assessment of intestinal epithelial cells is essential for studies of metabolism and disease. Here, we present a protocol to quantify fatty acid uptake and lipid accumulation in intestinal epithelial cell lines and primary intestinal organoids using a flow cytometry-based approach with BODIPY FL C16. We describe steps for assessing fatty acid uptake and accumulation in intestinal epithelial cell lines and intestinal organoids. This rapid and reproducible technique can also be adapted to investigate fatty acid metabolism in other cell types. For complete details on the use and execution of this protocol, please refer to Wu et al.1.
    Keywords:  Cell Biology; Cell culture; Cell isolation; Cell-based Assays; Flow Cytometry; Metabolism; Organoids
    DOI:  https://doi.org/10.1016/j.xpro.2026.104853
  20. Bioinformatics. 2026 Sep 22. pii: btag700. [Epub ahead of print]
       MOTIVATION: The identification and analysis of glycans using MALDI-TOF mass spectrometry is a critical task in glycomics research, yet it often requires complex data interpretation and manual processing. Existing software tools frequently lack automated solutions for efficient glycan annotation, data structuring and grouping, and semi-quantitative evaluation, making large-scale glycan analysis challenging. To address these limitations, we developed massMatchR, an open-source software tool designed to streamline the identification and quantification of glycans in MALDI-TOF spectra.
    RESULTS: massMatchR automates glycan identification by mapping experimentally detected m/z values from preprocessed MALDI-TOF-MS datasets to glycans from a user-defined database. The software provides both visual and tabular outputs, enabling rapid and accurate glycan interpretation. Additionally, massMatchR facilitates the export of structured data tables (e.g., Microsoft Excel) with predefined fields for m/z and intensity, supporting further analysis. A key feature of the software is its ability to perform semi-quantitative evaluation based on relative intensity calculations, allowing for comparisons across multiple samples. Freely available at http://www.imb.savba.sk/soft/massMatchR/ and on GitHub implemented in R, massMatchR offers a fast, reproducible, and customizable computational framework for glycomics and MALDI-TOF -based glycan analysis.
    AVAILABILITY: An implementation code is available on Github at https://github.com/bekegbor/massMatchR  and on Zenodo at  https://doi.org/10.5281/zenodo.20697072.
    SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
    DOI:  https://doi.org/10.1093/bioinformatics/btag700
  21. Cureus. 2026 Aug;18(8): e115101
      Proteomic analysis of hair follicles aids in the basic understanding of human scalp hair biology and can serve as a foundation for biomarker identification and targeted therapy in precision medicine. Proteomics of scalp hair follicles in the Indian population has not been reported previously. We performed Orbitrap mass spectrometry analysis of proteins extracted from plucked scalp hair follicles of five healthy, nonbalding donors. Proteins from hair follicles were resolved by SDS-PAGE, extracted, trypsin-digested, cleaned up using ZipTips, and purified on C18 reversed-phase Easy-columns for Orbitrap analysis. The Orbitrap mass spectrometry data were processed using Proteome Discoverer (Thermo Fisher Scientific, Waltham, MA, USA). The mass spectrometry proteomics data have been deposited in the ProteomeXchange Consortium via PRIDE, with the dataset identifier PXD034166. In this study, we identified 2,961 unique (nonredundant) proteins across all five samples and 190 proteins common to these samples. Ontology and pathway analyses were performed on the identified proteins. This study provides a well-annotated hair follicle proteomics repository of Indian scalp hair follicles.
    Keywords:  gene network; gene ontology; interactome analysis; orbitrap; pathways; plucked hair follicles; protein identification; protein purification; proteomics; scalp
    DOI:  https://doi.org/10.7759/cureus.115101
  22. Curr Issues Mol Biol. 2026 Aug 27. pii: 871. [Epub ahead of print]48(9):
      Forskolin (FSK) is a well-characterized small-molecule activator of adenylyl cyclase that drives direct neuronal transdifferentiation in human fibroblasts; however, the temporal sequence and coordinated relationships among proteomic and metabolic adaptations during the initiation phase of lineage conversion remain poorly understood. In this study, we applied data-independent acquisition (DIA)-based quantitative proteomics and untargeted metabolomics on BJ human dermal fibroblasts at three biological timepoints: pre-induction (day 0), commitment onset (day 2), and neuronal maturation (day 5). Under the established FSK-based induction protocol, BJ fibroblasts rapidly acquired neuronal-like features, with more than 90% of cells becoming TUJ1-positive by day 5. Proteomic profiling revealed a profound, dichotomous regulatory shift: time-dependent activation of core metabolic and energy pathways (glycolysis, the TCA cycle, and oxidative phosphorylation) coupled with persistent suppression of cell-cycle progression and DNA replication. Concordantly, global metabolomic profiling revealed a statistically unidirectional transition in metabolic states characterized by the progressive accumulation of phosphoenolpyruvate (PEP). Collectively, our findings identify coordinated remodeling of central carbon metabolism as a prominent early molecular feature associated with neuronal transdifferentiation under the FSK-based induction protocol. This study provides an integrated proteomic and metabolomic framework for understanding early molecular remodeling during chemically induced cell fate conversion and provides a basis for future functional studies of metabolic regulation during reprogramming.
    Keywords:  cell transdifferentiation; forskolin; metabolic remodeling; proteomics
    DOI:  https://doi.org/10.3390/cimb48090871
  23. J Chromatogr B Analyt Technol Biomed Life Sci. 2026 Sep 22. pii: S1570-0232(26)00399-5. [Epub ahead of print]1284 125310
      Serum neurotransmitter profiling is analytically challenging because the target panel includes highly polar compounds with markedly different ionization behaviors, while several catecholamine-related analytes are also susceptible to oxidation during thawing and handling. Here, we developed and validated a derivatization-free hydrophilic interaction liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of 15 serum neurotransmitters and related metabolites within a 12-min run. To improve the quantitative reliability of oxidation-prone analytes, serum samples were stabilized immediately after thawing with ascorbic acid before protein precipitation. The final workflow combined hydrophilic interaction liquid chromatography separation, stable isotope dilution, and single-step protein precipitation. The method showed good linearity across the validated concentration ranges for all analytes, with coefficients of determination above 0.99, limits of detection of 0.01-0.30 ng/mL, recoveries of 85.19% to 107.41%, and acceptable intra- and inter-day precision. Stability experiments further demonstrated marked signal loss for labile catecholamine-related analytes in the absence of antioxidant protection, whereas immediate post-thaw ascorbic acid stabilization substantially improved preservation of dopamine, norepinephrine, epinephrine, serotonin, and L-dopa during sample handling. Application of the method to serum samples from 188 pregnant women identified higher gamma-aminobutyric acid together with lower acetylcholine, choline, norepinephrine, L-dopa, serotonin, and 3-methoxytyramine in the antenatal depression group than in non-depressed controls. These findings support the use of this stability-aware hydrophilic interaction liquid chromatography-tandem mass spectrometry platform for cohort-scale serum neurotransmitter profiling and biomarker-oriented studies in pregnancy.
    Keywords:  Antenatal depression; Hydrophilic interaction liquid chromatography; Mass spectrometry; Neurotransmitters; Serum
    DOI:  https://doi.org/10.1016/j.jchromb.2026.125310