bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.05.27.656459

A Cyclic Arginine Adduct Eclipses Carboxymethylation as the Primary Glyoxal-Derived Advanced Glycation End-Product

Brutus, M. E.·Girard, C. S.·Jacob-Dolan, J. W.·Scheck, R. A.
View original source ↗Export metadata ↓

Abstract

Glyoxal (GO) is a highly reactive 1,2 dialdehyde implicated in the formation of a set of disease-associated post-translational modifications (PTMs) known as advanced glycation end products (AGEs). While GO has been widely reported to modify lysine to form the highly studied AGE carboxymethyllysine (CML), here we demonstrate that GO alone leads to highly chemoselective arginine glycation, yielding a stable glyoxal-derived hydroimidazolidine (GH-DH) product. This near-exclusively formed AGE has the same mass change as carboxymethylarginine (CMA), which implies that it may have been overlooked or misattributed in prior studies. In contrast, lysine modification by GO is highly dependent on the presence of hydride-based reducing agents, suggesting that prior reports may have artifactually generated CML through pervasive use of reductive amination protocols during sample preparation. These findings challenge the standing assumptions about the landscape of GO-derived glycation, emphasizing the importance of carefully considering the impact of experimental conditions in glycation studies. By redefining the complement of GO-derived AGEs, this study provides essential new information that is greatly needed for uncovering their biology, creating new tools for their study, and discovering therapies that ameliorate or mitigate their glycation-related damage.

Explore related subjects

biochemistryPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Brutus, M. E., Girard, C. S., Jacob-Dolan, J. W., Scheck, R. A.. 2025-05-30. A Cyclic Arginine Adduct Eclipses Carboxymethylation as the Primary Glyoxal-Derived Advanced Glycation End-Product. https://doi.org/10.1101/2025.05.27.656459

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Aging Remodels the Female Skeletal Muscle Proteome Toward Matrix, Chromatin and Lysosomal Programs that Track Loss of Physical Function

Loss of skeletal muscle strength and mobility is among the most consequential features of human aging, yet the molecular programs that accompany this decline in women remain poorly understood. Here, we performed deep comprehensive data-independent acquisition (DIA) proteomic profiling of vastus lateralis biopsies from 10 younger (24-30 years) and 10 older (70-84 years) healthy women enrolled through the NIH Common Fund Cellular Senescence Network (SenNet), with matched measurements of grip strength and gait speed. Of 2,391 quantified protein groups, 163 were significantly altered with age, and partial least squares-discriminant analysis completely separated the age groups (cross-validated AUC = 1.00). Older muscle showed increased extracellular matrix and vascular remodeling proteins (TIMP3, COL8A1, ELN, FBN1), nuclear, chromatin and RNA-binding proteins (HMGB1, HMGB2, histone H1.0, MATR3, NCL), and lysosomal and senescence-associated secretory phenotype (SASP)-associated proteins (CTSZ, CTSD, PSAP), together with reduced glycolytic and energetic proteins (GAPDH, ENO3, PHKA1, CYCS). Age effects were robust to adjust for body mass index (BMI). Integrating differential abundance, multivariate importance and participant-level consistency, we defined a 24-protein skeletal muscle aging signature whose score separated all younger from all elderly women. Combining grip strength and gait speed into a combined function score, we found that 23 of the 24 signature proteins correlated with physical function (FDR < 0.05), and the signature score correlated strongly with function (r = -0.79). The senescence-associated alarmins HMGB1 and HMGB2 emerged as lead proteins: HMGB1 showed the strongest association with function (r = -0.86), and both remained associated after adjustment for age group. Together, these data define a senotype proteomic program in aging female skeletal muscle and a molecular signature of muscle function that, after validation, may serve as a readout for interventions that aim to preserve physical performance in elderly women.

biochemistry↗
bioRxiv2026

SUMOylation Regulates IRF2BP2 Nuclear Localization and Stability

Interferon Regulatory Factor-2 Binding Protein 2 (IRF2BP2) is a transcriptional cofactor implicated in diverse biological processes. Although it functions primarily as a repressor, it can also activate gene expression. However, the mechanisms governing IRF2BP2 regulation remain poorly understood. Here, we demonstrate that IRF2BP2 interacts with UBE2I, the SUMO E2 ligase, and undergoes multi-SUMOylation, which enhances its nuclear localization. We further show that IRF2BP2 nuclear import is importin-{beta}-dependent and requires the functional nuclear localization signal (NLS). IRF2BP2 preferentially accumulates in transcriptionally active euchromatin in both resting and S-phase cells, consistent with its role in transcriptional control. We further reveal that SUMOylation contributes to IRF2BP2 stability. Moreover, IRF2BP2 is also ubiquitinated, predominantly through K6-linked ubiquitin chains, a non-proteolytic modification that aligns with our observation that IRF2BP2 is not degraded by the proteasome. Together, these findings identify SUMOylation and non-proteolytic ubiquitination as key mechanisms regulating IRF2BP2, highlighting a novel SUMO1-NLS-importin-{beta}-dependent pathway that governs its localization.

biochemistry↗
bioRxiv2026

S-adenosylmethionine supply controls DNA methylation turnover in synovial sarcoma

Background: Methionine is the nutrient source of the metabolite S-adenosylmethionine (SAM) used to methylate chromatin for regulation of gene expression. Disruptions to this metabolic supply, including nutritional deficiency of certain B vitamins, alter chromatin methylation and have been implicated in tumor growth. Objective: To define how cellular SAM supply controls DNA methylation dynamics and the disruption of oncogenic gene expression in synovial sarcoma. Methods: Cell line models of synovial sarcoma were treated with the DNA methyltransferase inhibitor azacitidine or the small-molecule MAT2A inhibitor AG-270, which blocks SAM synthesis from methionine. Intracellular SAM concentrations were quantified by liquid chromatography-mass spectrometry. Global DNA methylation rates were measured by stable isotope tracing with [2H3-methyl]-methionine. Genomic sites of altered DNA methylation were identified by EM-seq and the associated transcriptional changes measured by RNA-seq. Results: Inhibition of SAM synthesis reduced intracellular SAM concentration from 94 uM to 5.6 uM (p value < 0.0001) at 24 hours. This was associated with a 19% decrease (p value < 0.0001) in the global 5-methyldeoxycytosine turnover rate, while total DNA methylation levels were maintained. In contrast to the global DNA hypomethylation induced by azacitidine, SAM depletion resulted in a redistribution of DNA methylation with loss at 252 and gain at 206 genomic sites, and the transcriptional response to SAM depletion was not associated with changes in promoter methylation at the altered genes. Both azacitidine and SAM depletion activated mesenchymal genes, while suppressing cell cycle progression. Conclusions: Metabolic supply of SAM is a major regulator of DNA methylation turnover providing a mechanism by which nutritional or genetic disruptions to SAM metabolism can alter chromatin methylation and gene expression.

biochemistry↗