A chemoproteomics approach to profile phospholipase D-derived phosphatidyl alcohol interactions

Alcohol consumption leads to formation of phosphatidylethanol (PEth) via the transphosphatidylation activity of phospholipase D (PLD) enzymes. Though this non-natural phospholipid routinely serves as a biomarker of chronic alcoholism, its pathophysiological roles remain unknown. We use a minimalist diazirene alkyne alcohol as an ethanol surrogate to generate clickable, photoaffinity lipid reporters of PEth localization and lipid–protein interactions via PLD-mediated transphosphatidylation. Using click chemistry tagging, enrichment, and proteomics analysis, we identified the single-pass transmembrane protein basigin/CD147 as a high-confidence interaction partner of this photoaffinity lipid reporter. Here we perform in-cell photocrosslinking, followed by anti-FLAG affinity enrichment of FLAG-tagged basigin, to map the crosslinking sites and determine that the PAL lipid crosslinks to a C-terminal peptide of basigin-FLAG. This study provides a view of the molecular interactions of phosphatidyl alcohols and points to future work to connect such interactions to potential pathophysiological roles of PEth.