Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Master of Science

Program

Biochemistry

Supervisor

Shaw, Gary S.

Abstract

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.

Summary for Lay Audience

Proteins are essential machines inside our body that carry out a variety of roles to help keep us healthy, aiding in digestion, growth and our immune system. When these proteins are not functioning properly, it is possible to give rise to many illnesses and diseases. While there are many thousands of proteins that have been discovered, an essential part of protein discovery is to discover what the protein actually looks like. Knowing the structure of a protein can provide very valuable information to scientists, which can in turn lead to the discovery of medicine and therapies used to treat these diseases. In this thesis, we are interested in the shape and structure of a protein that is sometimes the root cause of Parkinson’s Disease. We use a variety of scientific techniques to figure out essential information of our protein of interest, which could provide an avenue for the development of therapies used to treat patients that are diagnosed with Parkinson’s Disease.

Available for download on Wednesday, September 30, 2020

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