Inactivation of cellular caspases by peptide-derived tryptophan and tyrosine peroxides

Research output: Contribution to journalJournal articleResearchpeer-review

Mark B Hampton, Philip E Morgan, Michael Jonathan Davies

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 languageEnglish
JournalFEBS letters
Volume527
Issue number1-3
Pages (from-to)289-92
Number of pages4
ISSN0014-5793
Publication statusPublished - 11 Sep 2002

    Research areas

  • Amino Acids, Caspase Inhibitors, Cysteine Proteinase Inhibitors, Dose-Response Relationship, Drug, Enzyme Activation, Humans, Hydrogen Peroxide, Jurkat Cells, Peroxides, Tryptophan, Tyrosine

ID: 138276610