title: Kinetics of phosphorothioate oligonucleotide metabolism in biological fluids.
abstract: The in vitro stability and metabolism of GEM[91, a 25mer phosphorothioate antisense oligonucleotide complementary to the gag mRNA region of HIV-1, was investigated using capillary electrophoresis (CE). The in vitro degradation of the parent compound at 37 degrees C was followed over the course of 120 h in human plasma. A CE method using laser-induced fluorescence detection was able to detect 5'-end intact metabolites including the parent compound extracted from biological fluids. Because the primary metabolic pathway is believed to be via 3'-exonuclease activity, the results of this study were compared with the stability of the compound in a solution containing 3'-exonuclease. The numerical solution of sequential first-order reactions was used to obtain kinetic parameters. Exonuclease digestion of the parent compound, as measured using an automated CE-UV instrument, yielded striking similarities between the two in vitro systems as well as between in vitro and in vivo systems.
authors.affiliation: Hybridon, Inc., 620 Memorial Drive, Cambridge, MA 02139, USA.
authors.forename: M
authors.initials: M
authors.lastname: Gilar
authors.forename: A
authors.initials: A
authors.lastname: Belenky
authors.forename: D L
authors.initials: DL
authors.lastname: Smisek
authors.forename: A
authors.initials: A
authors.lastname: Bourque
authors.forename: A S
authors.initials: AS
authors.lastname: Cohen
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000378:metabolism; D015683:Gene Products, gag / Q000235:genetics; D006801:Humans; D007700:Kinetics; D009841:Oligonucleotides / Q000097:blood* / Q000235:genetics
chemical_list: D015683:Gene Products, gag; D009841:Oligonucleotides