Mapping locations of parkin oxidation in comparison to parkin mutations found in PD patients. Parkin (PARK2, UniProt 060260; NCBI AB009973) with 465-aa residues and its various domains indicated [Ubiquitin-like (Ubl), RING I and II, and in-between RING (IBR) domains]. (A) Sulfonated peptides of parkin were identified by either Q-TOF and/or Ion trap MS/MS, and labeled by "─" corresponding to the location of their sequence. Complementary MS analysis demonstrated that the identified cysteine residues in peptide fragments of parkin in the RING and IBR domains (16/22 = 73%) were highly reactive with ROS and formed sulfination/sulfonation derivatives of cysteine. (B), Parkin mutations identified in patients with familial Parkinson's disease (http://www.uniprot.org/uniprot/O60260), revealing high homology with modifications induced by oxidative stress.