Reprogramming the Lipid Peroxidation Product 4-ONE as a Chemoselective Cleavable Crosslinker

ABSTRACT: Nature builds and stabilizes proteins through covalent biological glues, yet the logic and traceability of metabolite-driven crosslinking remain obscure. Here we reprogram the lipid peroxidation product 4-oxo-nonenal (4-ONE) into a metabolite-derived Cys-Lys biological glue and mass-cleavable crosslinker. Through a chemoselective two-step pathway, Michael addition to cysteine activates a latent aldehyde that cyclizes with lysine to form a stable pyrrole linkage under physiological conditions. Late-stage oxidation converts this linkage into a mass-cleavable pyrrole sulfoxide, establishing COSMIc (Crosslink Oxidation to Sulfoxide for Mass-Cleavable Interactomics) for site-resolved identification of linked residues through diagnostic sulfenic acid and dehydroalanine fragments. Beyond peptide stapling, macrocyclization, late-stage functionalization, selective protein modification, and illuminating hyperreactive Lys and Cys residues that define 4-ONE reactivity, COSMIc enables detection of structurally informative crosslinks in proteins, proteomes and the human 26S proteasome, where peroxide-induced sulfoxide formation markedly improves fragment assignment and residue-pair confidence. Together, these findings transform 4-ONE from a toxic electrophile into a programmable covalent connector for structural proteomics, covalent mapping and interactome analysis.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Anthony Ciancone  

LAB HEAD: Francis J. O'Reilly

PROVIDER: PXD077887 | Pride | 2026-06-22

REPOSITORIES: Pride