Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.26.4 (
RNase H
)
2,751
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Despite the key role played by the
RNase H
of human immunodeficiency virus-1 reverse transcriptase (HIV-1 RT) in viral proliferation, only a few inhibitors of
RNase H
have been reported. Using in vitro combinatorial selection methods and the
RNase H
domain of the HIV RT, we have selected double-stranded DNA thioaptamers (aptamers with selected thiophosphate backbone substitutions) that inhibit
RNase H
activity and viral replication. The selected thioaptamer sequences had a very high proportion of G residues. The consensus sequence for the selected thioaptamers showed G clusters separated by single residues at the 5'-end of the sequence. Gel electrophoresis mobility shift assays and nuclear magnetic resonance spectroscopy showed that the selected thioaptamer binds to the isolated
RNase H
domain, but did not bind to a structurally similar
RNase H
from Escherichia coli. The lead thioaptamer,
R12
-2, showed specific binding to HIV-1 RT with a binding constant (K(d)) of 70 nM. The thioaptamer inhibited the
RNase H
activity of intact HIV-1 RT. In cell culture, transfection of thioaptamer
R12
-2 (0.5 microg/mL) markedly inhibited viral production and exhibited a dose response of inhibition with
R12
-2 concentrations ranging from 0.03 to 2.0 microg/mL (IC(50) < 100 nM). Inhibition was also seen across a wide range of virus inoculum, ranging from a multiplicity of infection (moi) of 0.0005 to 0.05, with a reduction of the level of virus production by more than 50% at high moi. Suppression of virus was comparable to that seen with AZT when moi <or= 0.005.
...
PMID:Combinatorial selection, inhibition, and antiviral activity of DNA thioaptamers targeting the RNase H domain of HIV-1 reverse transcriptase. 1604 16
Oligonucleotide agents (ODN) are emerging as attractive alternatives to chemical drugs. However, the clinical use of ODNs as therapeutics has been hindered by their susceptibility to degradation by cellular enzymes and their limited ability to penetrate intact cells. We have used various liposome-mediated transfection agents, for the in vitro delivery of DNA thioaptamers into U373-MAGI-CCR5 cells. Our lead thioaptamer,
R12
-2, targets the
RNase H
domain of the HIV-1 reverse transcriptase (RT) and inhibits viral infection in U373-MAGI-CCR5 cells.
R12
-2, a 62-base-pair, double-stranded DNA molecule with a monothio-phosphate modified backbone, was selected through a novel combinatorial selection method. We studied the use of oligofectamine (OF), TFX-20, Transmessenger (TM), and Gene Jammer (GJ) for transfection of the thio-modified DNA aptamers. OF-transfected U373-MAGI-CCR5 cells resulted in 68% inhibition of HIV infection in the treated cells compared to the untreated control. Inhibition was observed in a dose-dependent manner with maximal inhibition of 83%. In this report, we demonstrate that monothioate-modified DNA duplex oligonucleotides can be efficiently delivered into cells by liposome-based transfection agents to inhibit HIV replication.
...
PMID:Delivery of double-stranded DNA thioaptamers into HIV-1 infected cells for antiviral activity. 1663 Nov 18
