title: Tailored hydrophobic cavities in oligonucleotide-steroid conjugates.
abstract: Hydrophobic pockets can be generated readily in aqueous solution by hybridization of oligonucleotide conjugates containing one or two androstane units inserted into each strand by short phosphoryl linkers. Both double- and triple-stranded complexes formed by the conjugates are stabilized by adding to the solution a water-soluble hydrophobic substrate, 3,17-diaminoandrostane dihydrochloride, that can bind in the pocket. This substrate has no effect on the dissociation of unmodified oligonucleotides, and 1,10-diaminodecane dihydrochloride has no effect on dissociation of complexes of these steroid conjugates under the same conditions. This system provides a new means for selectively modulating and triggering hybridization of oligonucleotide conjugates. Cetyltrimethylammonium bromide strongly enhances the stability of complexes of the steroid conjugates; however, it also leads to precipitation of complexes of unmodified oligonucleotides.
authors.affiliation: Department of Chemistry and Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA. r-letsinger@chem.nwu.edu
authors.forename: R L
authors.initials: RL
authors.lastname: Letsinger
authors.forename: S
authors.initials: S
authors.lastname: Chaturvedi
mesh_terms: D000731:Androstanes / Q000737:chemistry; D003959:Diamines / Q000737:chemistry; D007202:Indicators and Reagents; D008968:Molecular Conformation; D009841:Oligonucleotides / Q000737:chemistry*; D013256:Steroids / Q000737:chemistry*; D013696:Temperature
chemical_list: C065351:1,10-diaminodecane; D000731:Androstanes; D003959:Diamines; D007202:Indicators and Reagents; D009841:Oligonucleotides; D013256:Steroids