Prednisone as an Activator of Glycogen Phosphorylase b

Voiceover

Presenter(s)

Josh Burton

Abstract or Description

Glycogen phosphorylase catalyzes the breakdown of glycogen to glucose 1-phosphate. Regulation of glycogen metabolism is integral to maintaining healthy glucose levels in the body, and it is therefore important to understand effectors that control the activity of phosphorylase. Prednisone is a corticosteroid that is often prescribed to supplement low cortisol levels. Corticosteroids are known to increase blood glucose by acting as a steroid that promotes glycogen breakdown in skeletal muscle. This study attempts to determine if prednisone acts as a direct effector to glycogen phosphorylase, outside of its usual steroidal function. The role of prednisone as an effector of phosphorylase b was studied along with the known effectors of AMP and nicotinamide. This was done by performing enzyme assays of the reverse reaction of phosphorylase, where glycogen and G-1-P react to release inorganic phosphate. The concentration of the phosphate product was monitored by absorbance spectrometry to determine the enzymatic efficiency. In these assays, phosphorylase showed increased activity in the presence of prednisone and AMP, along with decreased activity in the presence of nicotinamide. These results suggest that prednisone acts as a direct activator to phosphorylase, which implicates the possibility of using it in treatment of other disorders, such as diabetes.

Mentor

Roberto De Guzman