Global Mapping of Protein–Lipid Interactions by Using Modified Choline-Containing Phospholipids Metabolically Synthesized in Live Cells

The protein–lipid interaction is an essential metabolic process that mediates cellular signaling and functions. Existing strategies for large-scale mapping studies of the protein–lipid interaction fall short in their incompatibility with metabolic incorporation or inability to remove unwanted interferences from lipidated proteins. By incorporating an alkyne-containing choline head group and a diazirine-modified fatty acid simultaneously into choline-containing phospholipids synthesized from live mammalian cells, protein–phospholipid interactions have been successfully imaged in live cells. Subsequent in situ profiling of the modified Cho phospholipid-crosslinked proteins followed by quantitative proteomics allowed identification of several hundred putative phospholipid-interacting proteins, some of which were further validated.