Mechanism of HIV-1 integrase inhibition by styrylquinoline derivatives in vitro.
Styrylquinoline derivatives (SQ) efficiently inhibit the 3'-processing activity of integrase (IN) with IC50 values of between 0.5 and 5 microM. We studied the mechanism of action of these compounds in vitro. First, we used steady-state fluorescence anisotropy to assay the effects of the SQ derivatives on the formation of IN-viral DNA complexes independently of the catalytic process. The IC50 values obtained in activity and DNA-binding tests were similar, suggesting that the inhibition of 3'-processing can be fully explained by the prevention of IN-DNA recognition. SQ compounds act in a competitive manner, with Ki values of between 400 and 900 nM. In contrast, SQs did not inhibit 3'-processing when IN-DNA complexes were preassembled. Computational docking followed or not by molecular dynamics using the catalytic core of HIV-1 IN suggested a competitive inhibition mechanism, which is consistent with our previous data obtained with the corresponding Rous sarcoma virus domain. Second, we used preassembled IN-preprocessed DNA complexes to assay the potency of SQs against the strand transfer reaction, independently of 3'-processing. Inhibition occurred even if the efficiency was decreased by about 5- to 10-fold. Our results suggest that two inhibitor-binding modes exist: the first one prevents the binding of the viral DNA and then the two subsequent reactions (i.e., 3'-processing and strand transfer), whereas the second one prevents the binding of target DNA, thus inhibiting strand transfer. SQ derivatives have a higher affinity for the first site, in contrast to that observed for the diketo acids, which preferentially bind to the second one.
Deprez
Eric
E
Centre National de la Recherche Scientifique Unité Mixte Recherche 8113, Laboratoire de Biotechnologies et Pharmacologie Génétique Appliquée, Ecole Normale Supérieure de Cachan, Cachan Cedex, France.
Barbe
Sophie
S
Kolaski
Macieij
M
Leh
Hervé
H
Zouhiri
Fatima
F
Auclair
Christian
C
Brochon
Jean-Claude
JC
Le Bret
Marc
M
Mouscadet
Jean-François
JF
D019380:Anti-HIV Agents / Q000494:pharmacology; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D019427:HIV Integrase / Q000187:drug effects / Q000378:metabolism*; D019428:HIV Integrase Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D011804:Quinolines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
D019380:Anti-HIV Agents; D019428:HIV Integrase Inhibitors; D011804:Quinolines; C481600:styrylquinoline; D004247:DNA; D019427:HIV Integrase