Display Settings:


Send to:

Choose Destination
See comment in PubMed Commons below
Chem Res Toxicol. 2009 Jun;22(6):1050-9. doi: 10.1021/tx9000144.

Covalent cross-linking of glutathione and carnosine to proteins by 4-oxo-2-nonenal.

Author information

  • 1Departments of Chemistry, Pharmacology, and Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA.


The lipid oxidation product 4-oxo-2-nonenal (ONE) derived from peroxidation of polyunsaturated fatty acids is a highly reactive protein cross-linking reagent. The major family of cross-links reflects conjugate addition of side chain nucleophiles such as sulfhydryl or imidazole groups to the C triple bond C of ONE to give either a 2- or 3-substituted 4-ketoaldehyde, which then undergoes Paal-Knorr condensation with the primary amine of protein lysine side chains. If ONE is intercepted in biological fluids by antielectrophiles such as glutathione (GSH) or beta-alanylhistidine (carnosine), this would lead to circulating 4-ketoaldehydes that could then bind covalently to the protein Lys residues. This phenomenon was investigated by SDS-PAGE and mass spectrometry (matrix-assisted laser desorption/ionization time-of-flight and LC-ESI-MS/MS with both tryptic and chymotryptic digestion). Under the reaction conditions of 0.25-2 mM ONE, 1 mM GSH or carnosine, 0.25 mM bovine beta-lactoglobulin (beta-LG), and 100 mM phosphate buffer (pH 7.4, 10% ethanol) for 24 h at 37 degrees C, virtually every Lys of beta-LG was found to be fractionally cross-linked to GSH. Cross-linking of Lys to carnosine was less efficient. Using cytochrome c and RNase A, we showed that ONE becomes more protein-reactive in the presence of GSH, whereas protein modification by 4-hydroxy-2-nonenal is inhibited by GSH. Stable antielectrophile-ONE-protein cross-links may serve as biomarkers of oxidative stress and may represent a novel mechanism of irreversible protein glutathionylation.

[PubMed - indexed for MEDLINE]
Free PMC Article

Images from this publication.See all images (13)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Scheme 1
Scheme 2
Scheme 3
Scheme 4
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Icon for American Chemical Society Icon for PubMed Central
    Loading ...
    Write to the Help Desk