Perfluoroalkyl acids (PFAAs) are a family of industrial chemicals used in everyday products ranging from non-stick coatings to fire-fighting foam. PFAAs are recognized as contaminants of emerging concern (CECs), and they are bioaccumulative, persistent and toxic. Unlike most other CECs, PFAAs preferentially bioaccumulate in protein rich parts of the body such as the blood, liver and kidneys; therefore, it is imperative to study PFAA-protein interactions. Human Serum Albumin (HSA) is used as a model protein when studying PFAA-protein binding to proteins since it is the most abundant protein in the blood and is involved in the reversible binding and transport of many ligands. In previous studies researchers have investigated PFAA-HSA binding, but most of these studies have focused on medium-chain length PFAAs; few studies have used one method to systematically quantify the binding of PFAAs of varying chain length and ionic head group to HSA. The goal of this study is to determine the binding affinities of short-, medium- and long-chain length perfluorocarboxylates and perfluorosulfonates (ranging from 4 to 12 carbons) in order to establish a relationship between PFAA chain length, as well as ionic head group, and HSA binding. Here, a systematic equilibrium dialysis method coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to selectively determine PFAA-HSA binding affinities. Our results show that all PFAAs studied bind to HSA using according to a two-class binding model, regardless of chain length or ionic head group, and the short-chain PFAAs bind only moderately weaker than the medium- and long-chain PFAAs. These results raise concern over whether or not the short-chain PFAA replacements are any safer than their predecessors.

Systematic investigation of the effects of perfluoroalkyl acid chain length and ionic head group on human serum albumin binding

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.