BreAsia Deal

Participant: PROMISE AGEP Research Symposium

BreAsia Deal

Department: Applied Mathematics and Statistics

Institution: University of Maryland, Baltimore County (UMBC)

 

2018 ABSTRACT

Modeling the Effect of Glucose Intake on a System with Simple Oscillatory Conditions

BreAsia Deal*, Adam Davison, Nicholas Eagles, Daniel Schneider

Glucose is perhaps the most basic source of fuel for animal cells, being the form of sugar that initiates glycolysis, which then leads to the TCA cycle, which feeds into oxidative phosphorylation. The human cell contains many enzymes that facilitate the generation of glucose from other sugars. Being such a key fuel to ATP generating processes, it is no surprise that the body needs some way to maintain a stable, necessary level of glucose, but without going above a dangerous threshold. This is primarily achieved through the storage of glucose in glycogen, a large branching polymer of glucose. The formation of glycogen from glucose and the degradation of glycogen to glucose are both regulated by various molecules. We pay particular interest to the effects of calcium concentrations on glycogen phosphorylase and the effects of glycose intake values and TCA demands on the system.

 

BIOGRAPHICAL SKETCH

My desire in graduate studies is to gain in-depth knowledge and mastery of applied mathematics in order to earn a PhD in Applied Mathematics, to become a professor and conduct new, innovative research. I aspire to specialize in mathematical modeling, partial differential equations, and computational biology in order to be prepared to research the applications of using computational techniques to study biological behavior. The research I have done in undergraduate studies fueled my desire to pursue my PhD. After my first semester at UMBC I was introduced to a Mathematical Physiology class, through taking the class has become my desire to pursue further studies and research in Mathematical Physiology. I have always been interested in the biological behaviors of different species and diseases, but mathematics is where I am the strongest and most knowledgeable in. It was not until that specific class that I realized they could work hand and hand to do research.

 

GENERAL SUMMARY OF GRADUATE RESEARCH

This research is based off of a Mathematical Physiology class project. It looks at the theoretical effects of simple and complex Ca2+ oscillations on the regulation of a phosphorylation-dephosphorization cycle process involved in glycogen degradation by glycogen phosphorylase. There are previous models found that allow Ca2+ to affect the function of glycogen phosphorylase. Ca2+ associated phosphorylation-dephosphorization cycle allows for glycogen phosphorylase to be converted from inactive b-form into the active a-form by phosphorylase kinase and the inactivated by a phosphatase. Phosphorylase kinase is Ca2+ sensitive. The model used allows for only the dynamics of Ca+ associated phosphorylation-dephosphorization cycle to control the activation of glycogen phosphorylase. The effects simple Ca2+ oscillations have on the fraction of active phosphorylase depends on the maximum rate of IP3, this value is called Vm5. This allows for the fraction of active phosphorylase to be independent from the increase of Ca2+ oscillations. However the fraction of active phosphorylase decreases during long periods of bursting Ca2+ oscillations. Most models have shown that both simple and complex Ca2+ oscillations decrease the effective Ca2+ threshold for the activation of glycogen phosphorylase. As a result Ca2+ could increase cellular signaling. We sought out to study the effects of calcium concentrations on glycogen phosphorylase and the effects of glycose intake values and TCA demands on the system during the phosphorylation-dephosphorization cycle process.