Mid‐Membrane Photolabeling of the Transmembrane Domain of Glycophorin A in Phospholipid Vesicles

: The tandem use of the photosensitive bola-amphiphile 1 (X=3 H) and cholesterol enabled the determination of the center of the transmembrane domain of glycophorin A (131 amino acid residues) in a membrane by selective functionalization of the protein within a phospholipid bilayer.