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 .
We have used 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 . 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 .
Recent work in the lab has focused on non-enzymatic reversible cysteine S-acetylation/S-acylation by acetyl-CoA and how this impacts on irreversible lysine N-acetylation/N-acylation. Surface cysteine residues readily react with acyl-CoAs and once the acyl moiety is localised on the surface of the protein it can be transferred to nearby lysine residues in a reaction that is enhanced by proximity .
- (2007) Detection of reactive oxygen species-sensitive thiol proteins by redox difference gel electrophoresis: implications for mitochondrial redox signaling. J Biol Chem 282, 22040-51
- (2010) Identification of S-nitrosated mitochondrial proteins by S-nitrosothiol difference in gel electrophoresis (SNO-DIGE): implications for the regulation of mitochondrial function by reversible S-nitrosation. Biochem J 430, 49-59
- (2015) Fasting, but Not Aging, Dramatically Alters the Redox Status of Cysteine Residues on Proteins in Drosophila melanogaster. Cell Rep
- (2017) Identification and Quantification of Protein S-nitrosation by Nitrite in the Mouse Heart during Ischemia. J Biol Chem
- (2017) Non-enzymatic N-acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S-acetylated Thiol Intermediate Sensitive to Glyoxalase II. Cell Rep 18, 2105-2112