The Effects of Glucose 6-Phosphate and Splenda Artificial Sweetener on Glycogen Phosphorylase b

Voiceover

Presenter(s)

Hunter Woosley

Abstract or Description

Glycogen phosphorylase b (GPb) is a phosphorylase enzyme found in the final step of gluconeogenesis that catalyzes the dissociation of a phosphate group from glucose 1-phosphate. As such, GPb is vital enzyme in regulating muscle and liver glycogen levels. Due to GPb’s importance in maintaining homeostasis, we were interested in determining what compounds may affect GPb activity. In this experiment, we investigated the impacts of varying compounds on GPb activity, including D-glucose 6-phosphate disodium salt hydrate (G6P) and Splenda Artificial Sweetener. We completed this experiment by constructing a standard curve of inorganic phosphate, analyzing the allosteric effects of adenosine 5’-monophosphate (AMP) on GPb, and evaluating the kinetic effects of G6P and Splenda Artificial Sweetener on GPb. We found that increasing concentrations of AMP resulted in a decreasing Vmax, suggesting that AMP is an allosteric inhibitor of G6P. Similarly, we also determined that G6P is an allosteric inhibitor of G6P. Finally, we concluded that Splenda Artificial Sweetener was an activator of G6P, as decreasing concentrations of Splenda Artificial Sweetener resulted in a decreasing Vmax . In future studies, we hope to investigate the mechanism by which Splenda Artificial Sweetener activates GPb.

Mentor

Roberto de Guzman