A Chemoproteomic Approach toward Probing the Interactomes of Perfluoroalkyl Substances

ABSTRACT: Poly- and perfluoroalkyl substances (PFASs) are widely used in industrial products and consumer goods. Due to their extreme-ly recalcitrant nature and potential bioaccumulation and toxicity, exposure to PFASs may result in adverse health outcomes in humans and wildlife. In this study, we developed a chemoproteomic strategy, based on the use of isotope-coded desthiobiotin-perfluorooctanephosphonic acid (PFOPA) probe and LC-MS/MS analysis, to profile PFAS-binding proteins. Targeted proteins were labeled with the desthiobiotin-PFOPA probe, digested with trypsin, and the ensuing desthiobiotin-conjugated peptides were enriched with streptavidin beads for LC-MS/MS analysis. We were able to identify 469 putative PFOPA-binding proteins. By conducting competitive binding experiments using a low (10 M) and high (100 M) concentrations of stable isotope-labeled PFOPA probes, we further identified 128 non-redundant peptides derived from 75 unique proteins that exhibit selective binding toward PFOPA. Additionally, we demonstrated that one of these proteins, fatty acid-binding protein 5 (FABP5), could interact directly with PFASs. Furthermore, the desthiobiotin-labeled lysine residues are located close to the fatty acid-binding pocket of FABP5, and the binding affinity varies with the structures of PFASs. Taken together, we developed a novel chemo-proteomic method for interrogating the PFAS-interacting proteome. The identification of these proteins sets the stage for un-derstanding the mechanisms through which exposure to PFASs confers adverse human health effects.

INSTRUMENT(S): Q Exactive HF

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Quanqing Zhang  

LAB HEAD: Quanqing Zhang

PROVIDER: PXD025757 | Pride | 2022-08-12

REPOSITORIES: pride