title: Study of phosphorothioate-modified oligonucleotide resistance to 3'-exonuclease using capillary electrophoresis.
abstract: The effect of phosphorothioate (PS) internucleotide linkages on the stability of phosphodiester oligodeoxyribonucleotides (ODNs) was investigated using 25-mer ODNs containing single or multiple PS backbone modifications. The in vitro stability of the oligomers was measured both in 3'-exonuclease solution and in plasma. For the separation of ODNs, capillary electrophoresis with a replaceable polymer separation matrix was used. As expected, DNA fragments with PS linkages at the 3'-end were found to be more resistant to 3'-exonuclease hydrolysis. Also increasing exonuclease resistance was the non-specific adsorption of phosphorothioate ODNs to enzyme.
authors.affiliation: Hybridon, Inc., Cambridge, MA 02139, USA.
authors.forename: M
authors.initials: M
authors.lastname: Gilar
authors.forename: A
authors.initials: A
authors.lastname: Belenky
authors.forename: Y
authors.initials: Y
authors.lastname: Budman
authors.forename: D L
authors.initials: DL
authors.lastname: Smisek
authors.forename: A S
authors.initials: AS
authors.lastname: Cohen
mesh_terms: D019075:Electrophoresis, Capillary; D005092:Exonucleases / Q000097:blood / Q000737:chemistry*; D015683:Gene Products, gag / Q000737:chemistry; D015497:HIV-1 / Q000737:chemistry; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000097:blood / Q000737:chemistry*; D016376:Oligonucleotides, Antisense / Q000097:blood / Q000737:chemistry*; D063086:Organothiophosphates / Q000097:blood / Q000737:chemistry*; D012367:RNA, Viral / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D015683:Gene Products, gag; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D063086:Organothiophosphates; D012367:RNA, Viral; D005092:Exonucleases; C022650:spleen exonuclease