Thermodynamic Modeling Of Phase Equilibria In Ternary Psm/Popc/Cholesterol Mixtures

Selen Berkman

School Name

Governor's School for Science and Math

Grade Level

12th Grade

Presentation Topic

Biochemistry

Presentation Type

Mentored

Mentor

Mentor: Dr. Uline; Department of Chemical Engineering, University of South Carolina

Abstract

In order to increase understanding of lipid rafts, we created a computational model of a ternary PSM/POPC/cholesterol system. We based the model off of the laws of thermodynamics and used coefficients from the Putzel and Schick model to describe interactions between saturated and unsaturated lipids and cholesterol. Using this model, we created a theoretical phase diagram that was aimed to mimic a phase diagram created from experimental data. We found that both the theoretical phase diagram and the experimental phase diagram formed closed loops, which indicated that phase separation into three phases only occurred when all three components of the system were present and not when there was only a binary system. Our model and the experimental model were similar in terms of size, shape, and tie-lines. This overall similarity may suggest that the formation of lipid rafts is due to thermodynamic phase separation. In future work, the thermodynamic consistence of this model should be examined.

Location

Owens 203

Start Date

4-16-2016 9:00 AM

COinS
 
Apr 16th, 9:00 AM

Thermodynamic Modeling Of Phase Equilibria In Ternary Psm/Popc/Cholesterol Mixtures

Owens 203

In order to increase understanding of lipid rafts, we created a computational model of a ternary PSM/POPC/cholesterol system. We based the model off of the laws of thermodynamics and used coefficients from the Putzel and Schick model to describe interactions between saturated and unsaturated lipids and cholesterol. Using this model, we created a theoretical phase diagram that was aimed to mimic a phase diagram created from experimental data. We found that both the theoretical phase diagram and the experimental phase diagram formed closed loops, which indicated that phase separation into three phases only occurred when all three components of the system were present and not when there was only a binary system. Our model and the experimental model were similar in terms of size, shape, and tie-lines. This overall similarity may suggest that the formation of lipid rafts is due to thermodynamic phase separation. In future work, the thermodynamic consistence of this model should be examined.