Mechanism of action of a novel viral mutagenic covert nucleotide: molecular interactions with HIV-1 reverse transcriptase and host cell DNA polymerases.
A novel non-chain terminating nucleoside analog anti-HIV inhibitor, KP-1212 has been designed to form base pairs with multiple bases that may lead to mutagenesis in the HIV-1 viral genome. After multiple replication cycles, the accumulation of mutations surpasses a crucial threshold beyond which the virus can no longer replicate. HIV-1 reverse transcriptase (RT) incorporates the KP-1212 monophosphate into the genome during viral replication after metabolic activation of the KP-1212 nucleoside to the triphosphate. The propensity for forming alternate base pairs with the KP-1212 nucleotide leads to mismatched nucleotides and the subsequent misincorporation is the basis for the inhibitory activity. The results showed that HIV-1 RT and human mitochondrial DNA polymerase (Pol gamma) incorporated KP-1212-TP with a significant level of efficiency, whereas mouse DNA polymerase beta (Pol beta) did not. Misincorporation studies suggest that both HIV-1 RT and Pol gamma may cause mutations at significantly high rates. These in vitro data confirm the mechanistic basis of KP-1212 as a viral mutagen but suggest that there may be a potential for toxicity to the mitochondria.
Murakami
Eisuke
E
Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520-8066, USA.
Basavapathruni
Aravind
A
Bradley
William D
WD
Anderson
Karen S
KS
D019380:Anti-HIV Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D001667:Binding, Competitive; D004259:DNA-Directed DNA Polymerase / Q000187:drug effects / Q000378:metabolism*; D003845:Deoxycytosine Nucleotides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008928:Mitochondria / Q000201:enzymology; D009154:Mutation; D019384:Nucleic Acid Synthesis Inhibitors
D019380:Anti-HIV Agents; D003845:Deoxycytosine Nucleotides; D019384:Nucleic Acid Synthesis Inhibitors; C024107:2'-deoxycytidine 5'-triphosphate; D054303:HIV Reverse Transcriptase; D004259:DNA-Directed DNA Polymerase