a synthetic ligand termed "Streptaphage" that enables efficient cellular uptake of the bacterial protein streptavidin by promoting noncovalent interactions with cholesterol and sphingolipid-rich lipid raft subdomains of cellular plasma membranes; the Streptaphage ligand comprises an N-alkyl derivative of 3 beta-cholesterylamine linked to the carboxylate of biotin through an 11-atom tether; structure in first source
