Disruption of HIV-1 integrase-DNA complexes by short 6-oxocytosine-containing oligonucleotides.
We recently found that oligonucleotides containing the 6-oxocytosine heterocyclic base are efficient inhibitors of the HIV-1 integrase in vitro [Brodin, P., et al. (2001) Nucleosides Nucleotides Nucleic Acids 20, 481-486]. In this report, we demonstrate that the inhibition arises from a noncompetitive mechanism in which the modified oligonucleotide attacks the integrase-DNA complex, leading to its active disruption. This conclusion is based on the following results. First, despite the fact that the respective affinities of a 6-oxocytosine-containing oligonucleotide and of its nonmodified counterpart for integrase were identical, only the modified compound inhibited the enzyme activities. Second, DNA binding and UV cross-linking assays indicated that the 6-oxocytosine-containing oligonucleotide prevented the formation of a stable integrase-DNA complex. Third, the kinetics of the dissociation of the integrase-DNA complex were dramatically accelerated in the presence of the modified ODN, whereas the nonmodified counterpart did not influence the dissociation. This mechanism was supported by the ability of the 6-oxocytosine-containing oligonucleotide to inhibit the strand transfer activity of HIV-1 preintegration complexes in vitro. Disruption of integrase-DNA complexes by 6-oxocytosine-containing oligonucleotides constitutes an original mechanism of integration inhibition, therefore suggesting a strategy for searching for inhibitors of the HIV-1 preintegration complexes.
Brodin
Priscille
P
Institut Gustave Roussy, UMR 8532, 39 rue Camille Desmoulins, 94805 Villejuif, France.
Pinskaya
Marina
M
Buckle
Malcolm
M
Parsch
Uwe
U
Romanova
Elena
E
Engels
Joachim
J
Gottikh
Marina
M
Mouscadet
Jean-François
JF
D001667:Binding, Competitive; D003562:Cytidine / Q000031:analogs & derivatives* / Q000737:chemistry*; D003596:Cytosine / Q000737:chemistry; D004279:DNA, Viral / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D019427:HIV Integrase / Q000737:chemistry / Q000378:metabolism*; D019428:HIV Integrase Inhibitors / Q000737:chemistry* / Q000378:metabolism; D016325:HIV Long Terminal Repeat; D009841:Oligonucleotides / Q000737:chemistry* / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012367:RNA, Viral / Q000037:antagonists & inhibitors; D013379:Substrate Specificity; D013941:Thymine / Q000737:chemistry; D016662:Virus Integration / Q000502:physiology
D004279:DNA, Viral; D019428:HIV Integrase Inhibitors; D009841:Oligonucleotides; D012367:RNA, Viral; C095942:6-oxocytidine; D003562:Cytidine; D003596:Cytosine; D019427:HIV Integrase; D013941:Thymine