Jet-Alert®’s effects on Glycogen Phosphorylase b’s Reaction Kinetics

Voiceover

Presenter(s)

Josh Winscott

Abstract or Description

The project's goal was to test the effect of Jet-Alert® tablets on the enzymatic kinetics of Glycogen Phosphorylase b (GPb). In times of low cellular energy and high AMP, this enzyme catalyzes the breakdown of glycogen stores into glucose-1-phosphate (G-1-P). In the cell, G-1-P removal shifts the equilibrium towards the forward reaction; in the lab, this was not possible to replicate, and the reverse reaction ensued. The reactions within all assays occurred in reverse to quantify inorganic phosphate (Pi) levels through absorbance measurements. Jet-Alert Double Strength 200 mg tablet’s active ingredient, caffeine, served as the experimental GPb effector. A positive-effector control assay was run with only increasing levels of AMP. The negative-control assay was run with a constant level of 4 mM of AMP and increasing concentration levels of Glucose-6-Phosphate (G-P-6), a known GPb feedback inhibitor. The experimental assay was run with a constant level of 4 mM of AMP and increasing concentration levels of Jet-Alert. The results of each enzymatic kinetic assay were combined with the Pi standard assay results to create a Michaelis-Menton plot. The final plots helped determine how Jet-Alert impacted GPb’s Vmax and Km. The negative-control assay depicted a decrease in Vmax from 1.924 mM/min to 1.355 mM/min; the Km also increased from 15.88 mM to 52.85 mM. The Jet-Alert assay depicted a decrease in Vmax from 1.924 mM/min to 1.804 mM/min; the Km also increased from 15.88 mM to 34.87 mM.

Mentor

Roberto De Guzman