Date Thesis Awarded
5-2017
Access Type
Honors Thesis -- Access Restricted On-Campus Only
Degree Name
Bachelors of Science (BS)
Department
Chemistry
Advisor
Dr. Lisa Landino
Committee Members
Dr. Christopher Abelt
Dr. Douglas Young
Abstract
Reactive oxygen species (ROS) play a critical role in intracellular signaling mechanisms. These small molecules initiate reversible, post-translational modifications of redox-sensitive proteins. Pyruvate kinase (PK) is a key glycolytic enzyme whose activity is modulated by ROS; oxidation inhibits its catalytic function through a reaction at a critical cysteine near the active site. PK’s central role in moderating glycolytic flux makes it highly regulated through both structural and allosteric effectors. This research explores the extent of cysteine modification of PK under various models of intracellular conditions. PK was treated with oxidants and allosteric regulators, and changes in the enzyme’s activity and cysteine reactivity were monitored through spectrophotometric and SDS-PAGE assays. Addition of oxidants decreased both PK activity and cysteine accessibility. Addition of ATP and fructose-1,6-bisphosphate (FBP) protected cysteines from tagging and oxidation. Other allosteric effectors like PEP had no effect on cysteine accessibility at low concentrations. Quantifying the reactivity of PK’s cysteines allows researchers to further understand the nuanced relationship that exists between intracellular redox conditions and protein activity. This research has been completed in tandem with Julia Zuercher.
Recommended Citation
Duff, Mary Cate, "Metabolism and Oxidative Stress: Understanding the Role of Reactive Cysteines in Pyruvate Kinase" (2017). Undergraduate Honors Theses. William & Mary. Paper 1262.
https://scholarworks.wm.edu/honorstheses/1262
