Thursday, December 26, 2019

URSP Student Ume Tahir Investigates the Thermodynamics of Perfume-Myelin Basic Protein Interactions Using Equilibrium Headspace Gas Chromatography

I was initially interested in doing research after having taken CHEM 321 (Quantitative Chemical Analysis), possibly in the areas of physical/analytical chemistry. The project that I am currently working on has spanned the course of three semesters, and explores the thermodynamics of the noncovalent interactions between perfume components and various proteins, making use of equilibrium headspace gas chromatography. This is an incredible combination of my interests, ranging from understanding protein behavior to deriving thermodynamic quantities. My long-term goal is to pursue a PhD in biophysical chemistry, and this project has provided me with a variety of knowledge and skills that can be applied in that pursuit.

This work involves preparation of a protein sample of an ideal concentration that gives us sufficient data prior and subsequent to the critical aggregation concentration. The solution is stored in an auto syringe that is programmed to inject a particular volume of protein over certain time intervals. A sample cell contains an infinitely dilute perfume solution, into which the protein is injected. The vapor in this cell is sampled after an equilibration period. Changes in vapor composition are tracked with equilibrium headspace gas chromatography. The resulting data is used to calculate many thermodynamic parameters. This includes association constants for perfume components and monomeric protein, activity coefficients, and partition coefficients. These values allow judgement of the thermodynamic favorability of the noncovalent interactions involved.

Although I have started with the experimental phase of my work this semester, I am working on data analysis, so am unable to say anything conclusive about results. Based on our outcomes in previous semester, I am anticipating highly thermodynamically favorable noncovalent interactions.