Abstract
Peroxides generated on peptides and proteins within cells, as a result of radical attack or reaction with singlet oxygen, are longer-lived than H(2)O(2) due to their poor removal by protective enzymes. These peroxides readily oxidize cysteine residues and can inactivate thiol-dependent enzymes. We show here that Trp- and Tyr-derived peptide peroxides, generated by singlet oxygen, inhibit caspase activity in the lysates of apoptotic Jurkat cells. N-Ac-Trp-OMe peroxide was the most effective inhibitor, and was 30-fold more effective than H(2)O(2) under identical conditions. As such, protein peroxides could modulate the progression of apoptosis in cells in which they are generated.
| Original language | English |
|---|---|
| Journal | FEBS Letters |
| Volume | 527 |
| Issue number | 1-3 |
| Pages (from-to) | 289-92 |
| Number of pages | 4 |
| ISSN | 0014-5793 |
| Publication status | Published - 11 Sept 2002 |
Keywords
- Amino Acids
- Caspase Inhibitors
- Cysteine Proteinase Inhibitors
- Dose-Response Relationship, Drug
- Enzyme Activation
- Humans
- Hydrogen Peroxide
- Jurkat Cells
- Peroxides
- Tryptophan
- Tyrosine