Although previous studies from this group have indicated the absolute requirement for reverse transcriptase (RT)-associated ribonuclease H (RNase H) activity for virus replication, this enzymatic function has received little attention as an antiviral target. However, the finding that HIV-1 RNase H and integrase (IN) are derived from the same superfamily of nucleotidyl transferases has allowed the implementation of screening strategies based on IN inhibitors previously identified at the NCI. Several natural products have initially been identified that act on both RNase H and IN, while a limited number show selectivity for the individual proteins. Subsequently, two fluorescence-based assays have been implemented in collaboration with the NCI Molecular Targets Development Program for high throughput screening of several NCI libraries (n = 250,000) for inhibitors of HIV-1 RNase H function (Parniak et al., 2003, Chan et al., 2004). Several classes of inhibitors, active at sub-micromolar concentrations, have been identified with enhanced specificity for HIV-1 RNase H. Presently, the binding site for inhibitors on the HIV-1 E.coli and human RNases H is being determined by both X-ray crystallography and high resolution mass spectrometry. A patent on a selected group of compounds with antiviral activity has also been submitted.

Agency
National Institute of Health (NIH)
Institute
Division of Basic Sciences - NCI (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC010494-02
Application #
7058964
Study Section
(RML)
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2004
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Wendeler, Michaela; Lee, Hsiu-Fang; Bermingham, Alun et al. (2008) Vinylogous ureas as a novel class of inhibitors of reverse transcriptase-associated ribonuclease H activity. ACS Chem Biol 3:635-44
Bokesch, Heidi R; Wamiru, Antony; Le Grice, Stuart F J et al. (2008) HIV-1 ribonuclease H inhibitory phenolic glycosides from Eugenia hyemalis. J Nat Prod 71:1634-6
Budihas, Scott R; Gorshkova, Inna; Gaidamakov, Sergei et al. (2005) Selective inhibition of HIV-1 reverse transcriptase-associated ribonuclease H activity by hydroxylated tropolones. Nucleic Acids Res 33:1249-56
Chan, King C; Budihas, Scott R; Le Grice, Stuart F J et al. (2004) A capillary electrophoretic assay for ribonuclease H activity. Anal Biochem 331:296-302
Parniak, Michael A; Min, Kyung-Lyum; Budihas, Scott R et al. (2003) A fluorescence-based high-throughput screening assay for inhibitors of human immunodeficiency virus-1 reverse transcriptase-associated ribonuclease H activity. Anal Biochem 322:33-9