Peptide−Oligonucleotide Phosphorothioate Conjugates with Membrane Translocation and Nuclear Localization Properties

Abstract
Eighteen peptide−oligonucleotide phosphorothioate conjugates were prepared in good yield and thoroughly characterized with electrospray ionization mass spectra. When applied to the living cells, conjugates exhibiting membrane translocation and nuclear localization properties displayed efficient intracellular penetration but failed to show any serious antisense effect. Studies on the intracellular distribution of the fluorescein-labeled conjugates revealed their trapping in endosomes.