Antibody-Free Profiling of Lysine Dimethylation via Chemoselective OxidationCoupled Reversible Enrichment

ABSTRACT: Lysine dimethylation (Kme2) is a critical post-translational modification (PTM), while its comprehensive analysis remains challenging due to low stoichiometry and lack of pan-specific antibodies. Here, we developed an antibody-free proteomics strategy combining selective fluorine-mediated oxidation with reversible hydrazide enrichment. In this approach, Kme2 residues were oxidized to aldehyde, covalently captured by hydrazine-functionalized beads, and reversibly released for MS analysis. This approach achieved high specificity and reproducibility, identifying 293 and 284 site-specific Kme2 events in HeLa and A549 cells, respectively. Based on the excellent reproducibility, quantitative analysis enabled precise characterization of Kme2 sites sensitive to the pan-methylation inhibitor Adox. Applied to breast cancer models, the approach revealed cell-type-specific Kme2 signatures: metastatic MDA-MB-231 cells exhibited cytoskeletal and metabolic adaptation Kme2 events, while proliferative MCF-7 cells prioritized translational machinery components. Our antibody-free platform provides a robust tool for Kme2 mapping and methylation-targeted drug discovery, offering insights into epigenetic regulation in cancer progression.

ORGANISM(S): Homo Sapiens

SUBMITTER: Hongqiang Qin  

PROVIDER: PXD078472 | iProX | Mon May 18 00:00:00 GMT+01:00 2026

REPOSITORIES: iProX