Chemical characterization of a protein-4-hydroxy-2-nonenal cross-link: immunochemical detection in mitochondria exposed to oxidative stress.

Published

Journal Article

We have previously shown that incubation of the model protein glucose-6-phosphate dehydrogenase (Glu-6-PDH) from the bacterium Leuconostoc mesenteroides with 4-hydroxy-2-nonenal (HNE), a major product of lipid peroxidation, results in the formation of cross-linked protein. HNE-modified protein is resistant to proteolytic degradation and acts as an inhibitor of the multicatalytic proteinase. It was therefore important to establish the chemistry of the cross-linking reaction. The formation of cross-linked Glu-6-PDH is associated with the nearly exclusive loss of lysine residues. For this reason the reaction of N-acetyllysine with HNE has been investigated. The epsilon-amino group of lysine reacts with the double bond (C3) and the carbonyl (C1) functions of HNE via Michael addition and Schiff base formation resulting in the production of a 2:1 amino acid-HNE cross-link. Chromatographic detection of this adduct in the acid hydrolysate of HNE-treated Glu-6-PDH reveals that this chemistry is responsible for the formation of cross-linked protein. Antibody to the reduced form of the 2:1 lysine-HNE adduct was prepared. The antibody was used to demonstrate that exposure of isolated liver mitochondria to oxidative stress led to the formation of intra- and intermolecular protein-HNE cross-links. The results of the present study indicate that modifications to protein by lipid peroxidation products may be physiologically relevant and could contribute to the disease- and age-related buildup of damaged protein.

Full Text

Duke Authors

Cited Authors

  • Cohn, JA; Tsai, L; Friguet, B; Szweda, LI

Published Date

  • April 1996

Published In

Volume / Issue

  • 328 / 1

Start / End Page

  • 158 - 164

PubMed ID

  • 8638925

Pubmed Central ID

  • 8638925

Electronic International Standard Serial Number (EISSN)

  • 1096-0384

International Standard Serial Number (ISSN)

  • 0003-9861

Digital Object Identifier (DOI)

  • 10.1006/abbi.1996.0156

Language

  • eng