Redox Proteomics

Altering the redox state of cysteine residues on protein surfaces is an important response to environmental challenges. We have investigated modifications to protein thiols in enriched mitochondrial fractions using a modified form of 2D electrophoresis that we have called Redox-DIGE. We have observed a number of cysteine residues that are sensitive enough to respond to plausible in vivo concentrations (low µM) of reactive oxygen or nitrogen species [1][2].

Currently we use a redox proteomic technique called oxidative isotope-coded affinity tags (OxICAT) to assess cysteine-residue redox changes. We used this approach to simultaneously identify and quantify the redox state of several hundred cysteine residues in Drosophila melanogaster in vivo during ageing and fasting [3]. We have also used it to show that in mouse in vivo protein S-nitrosation occurs in response to the combination of ischemia and nitrite [4].