Drug targeting of HIV-1 RNA.DNA hybrid structures: thermodynamics of recognition and impact on reverse transcriptase-mediated ribonuclease H activity and viral replication.
RNA degradation via the ribonuclease H (RNase H) activity of human immunodeficiency virus type I (HIV-1) reverse transcriptase (RT) is a critical component of the reverse transcription process. In this connection, mutations of RT that inactivate RNase H activity result in noninfectious virus particles. Thus, interfering with the RNase H activity of RT represents a potential vehicle for the inhibition of HIV-1 replication. Here, we demonstrate an approach for inhibiting the RNase H activity of HIV-1 RT by targeting its RNA.DNA hybrid substrates. Specifically, we show that the binding of the 4,5-disubstituted 2-deoxystreptamine aminoglycosides, neomycin, paromomycin, and ribostamycin, to two different chimeric RNA-DNA duplexes, which mimic two distinct intermediates in the reverse transcription process, inhibits specific RT-mediated RNase H cleavage, with this inhibition being competitive in nature. UV melting and isothermal titration calorimetry studies reveal a correlation between the relative binding affinities of the three drugs for each of the chimeric RNA-DNA host duplexes and the relative extents to which the drugs inhibit RT-mediated RNase H cleavage of the duplexes. Significantly, this correlation also extends to the relative efficacies with which the drugs inhibit HIV-1 replication. In the aggregate, our results highlight a potential strategy for AIDS chemotherapy that should not be compromised by the unusual genetic diversity of HIV-1.
Li
Tsai-Kun
TK
Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854-5635, USA.
Barbieri
Christopher M
CM
Lin
Hsin-Chin
HC
Rabson
Arnold B
AB
Yang
Gengcheng
G
Fan
Yupeng
Y
Gaffney
Barbara L
BL
Jones
Roger A
RA
Pilch
Daniel S
DS
D000617:Aminoglycosides / Q000494:pharmacology; D001667:Binding, Competitive; D002942:Circular Dichroism; D004279:DNA, Viral / Q000037:antagonists & inhibitors / Q000737:chemistry*; D016503:Drug Delivery Systems / Q000379:methods; D004789:Enzyme Activation / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D015497:HIV-1 / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D009355:Neomycin / Q000378:metabolism / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes / Q000037:antagonists & inhibitors / Q000737:chemistry; D010303:Paromomycin / Q000378:metabolism / Q000494:pharmacology; D012367:RNA, Viral / Q000037:antagonists & inhibitors / Q000737:chemistry*; D018894:Reverse Transcriptase Inhibitors / Q000378:metabolism / Q000494:pharmacology; D016914:Ribonuclease H / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012271:Ribostamycin / Q000378:metabolism / Q000494:pharmacology; D013816:Thermodynamics; D014779:Virus Replication / Q000235:genetics
D000617:Aminoglycosides; D004279:DNA, Viral; D009692:Nucleic Acid Heteroduplexes; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D012271:Ribostamycin; D010303:Paromomycin; D054303:HIV Reverse Transcriptase; D016914:Ribonuclease H; D009355:Neomycin