Inactivation of cellular caspases by peptide-derived tryptophan and tyrosine peroxides
Research output: Contribution to journal › Journal article › Research › peer-review
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.
|Number of pages||4|
|Publication status||Published - 11 Sep 2002|
- Amino Acids, Caspase Inhibitors, Cysteine Proteinase Inhibitors, Dose-Response Relationship, Drug, Enzyme Activation, Humans, Hydrogen Peroxide, Jurkat Cells, Peroxides, Tryptophan, Tyrosine