Abstract
Oxidative modification of glucose-6-phosphate dehydrogenase (Glu-6-PDH), as observed for other proteins, increases the susceptibility of the protein to degradation by the multicatalytic proteinase/proteasome (MCP). Oxidized Glu-6-PDH is, however, more prone to cross-linking reactions by the lipid peroxidation product 4-hydroxy-2-nonenal (HNE), processes which render the protein resistant to proteolysis. In addition, HNE cross-linked protein inhibits the degradation of oxidatively modified glutamine synthetase by the MCP. In contrast to oxidized Glu-6-PDH, which inhibits the proteolysis of GS in a competitive manner, HNE cross-linked protein acts as a noncompetitive inhibitor. As judged by binding of the hydrophobic fluorescent probe 8-anilino-1-naphthalenesulfonic acid, a common structural feature of both macromolecular substrates and inhibitors of the MCP is an increased accessibility of hydrophobic regions on the protein.
Original language | English (US) |
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Pages (from-to) | 21-25 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 405 |
Issue number | 1 |
DOIs | |
State | Published - Mar 17 1997 |
Keywords
- 4-Hydroxy-2-nonenal
- Free radicals
- Glucose-6-phosphate dehydrogenase
- Hydrophobicity
- Lipid peroxidation
- Multicatalytic proteinase (20S proteasome)
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology