Date of Graduation


Document Type


Degree Name

Bachelor of Science

Degree Level



Biological Sciences


Millett, Francis

Committee Member/Reader

Douglas, Michael

Committee Member/Second Reader

Forbes, Kristian

Committee Member/Third Reader

Wheeler, Jill


Cytochrome c (Cc) is a multifunction protein that has important life and death functions in the cell. In the electron transport chain (ETC), Cc transfers electrons from cytochrome bc1 to cytochrome c oxidase (CcO), which helps build the electrochemical gradient that drives ATP synthase. The reaction of Cc with CcO is very important in ETC regulatory processes. Previous research shows phosphorylation sites in Cc that affect the binding with CcO, with measurable effects on kd, kf, and KD. These effects result in changes in mitochondrial membrane potentials, respiration, and reactive oxygen species (ROS) scavenging. This research involved a new phosphorylation site on Cc, Tyr 46. Using site-directed mutagenesis, we mutated tyrosine to a glutamate residue. Steady-state kinetic and analytical ultracentrifuge experiments were performed to examine the binding strength of the Cc:CcO complex. Results showed slight differences between Y46E and WT Human Cc, possibly indicating that Y46E changes the binding complex. However, the differences were small enough to say that Y46E had no significant effects on the Cc:CcO binding complex.


cytochrome c, cytochrome c oxidase, reaction, phosphorylation