Parkin Structural Perturbations in Oxidative Stress

Parkin is an RBR E3 ubiquitin ligase that is implicated in the development of Parkinson’s Disease. Its ligase activity is specific for mitochondrial proteins, recognizing, tagging and signalling mitochondria to the autophagosome for degradation. Parkin contains eight Zn2+ binding sites and a total of 35 cysteines, which are especially susceptible to oxidative modification. Hallmarks of Parkinson’s Disease is oxidative stress and an increase of reactive oxygen species. In this work, I used biophysical methods such as mass spectrometry, CD spectroscopy and gel-based assays in addition to zinc and H2O2 detection methods to explore a potentially novel redox function for parkin. This thesis shows that parkin is capable of acting as a redox molecule, and oxidative modifications result in the liberation of two Zn2+ ions and extensive disulfide linkage formation. Parkin ubiquitination activity is also increased by mild oxidation but is eventually abolished. My research provides insight into novel functions of parkin