Investigation of the Mechanism of Binding of Perfluoroalkyl Acids with Human Serum Albumin Using an Improved Approach to Equilibrium Dialysis
Date of Award
Bachelor of Science
Laura A. MacManus-Spencer
acids, toxicity, chemicals, dialysis, kidneys
Perfluoroalkyl acids (PFAAs) are used to produce many consumer products, but their bioaccumulative and toxic properties and their global persistence in the environment are major concerns. In particular, PFAAs have been shown to accumulate in the blood, liver, and kidneys of organisms. As such, it is important to elucidate the toxicokinetics of PFAAs by quantitatively and qualitatively characterizing the binding mechanism of PFAAs to human serum albumin (HSA). In this study, the binding of PFAAs to HSA are studied via a high-throughput equilibrium dialysis method that utilizes the 96-well Equilibrium Dialyzer coupled with sample quantitation using liquid chromatography tandem-mass spectrometry (LC-MS/MS). This equilibrium dialysis method provides an efficient and direct way to measure protein-ligand binding constants. Using the described methods, it was determined that HSA has approximately two binding sites associated with a high affinity (105 M–1) as well as approximately fifteen binding sites associated with a lower affinity (103 M-1) for perfluorooctanoic acid (PFOA). These binding constants indicate that PFOA binds to HSA with the same affinity as some endogenous ligands, which illuminates the toxicity concerns of these chemicals. Future applications of this method could include measuring the binding constants of other PFAAs to HSA, characterizing the binding mechanism of PFAAs to HSA by examining the effect of various pH and ionic strength values with respect to binding strength, and measuring binding constants of PFAAs to myoglobin and hemoglobin.
Morris, Michael, "Investigation of the Mechanism of Binding of Perfluoroalkyl Acids with Human Serum Albumin Using an Improved Approach to Equilibrium Dialysis" (2014). Honors Theses. 562.