scholarly journals 1,2,4-Triazolo[1,5-a]pyrimidines as a Novel Class of Inhibitors of the HIV-1 Reverse Transcriptase-Associated Ribonuclease H Activity

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1183 ◽  
Author(s):  
Jenny Desantis ◽  
Serena Massari ◽  
Angela Corona ◽  
Andrea Astolfi ◽  
Stefano Sabatini ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Rnase H ◽  
Ribonuclease H ◽  
Allosteric Site ◽  
Viral Reservoirs ◽  
Enzymatic Function ◽  
Immunodeficiency Virus ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Hiv 1

Despite great efforts have been made in the prevention and therapy of human immunodeficiency virus (HIV-1) infection, however the difficulty to eradicate latent viral reservoirs together with the emergence of multi-drug-resistant strains require the search for innovative agents, possibly exploiting novel mechanisms of action. In this context, the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H), which is one of the few HIV-1 encoded enzymatic function still not targeted by any current drug, can be considered as an appealing target. In this work, we repurposed in-house anti-influenza derivatives based on the 1,2,4-triazolo[1,5-a]-pyrimidine (TZP) scaffold for their ability to inhibit HIV-1 RNase H function. Based on the results, a successive multi-step structural exploration around the TZP core was performed leading to identify catechol derivatives that inhibited RNase H in the low micromolar range without showing RT-associated polymerase inhibitory activity. The antiviral evaluation of the compounds in the MT4 cells showed any activity against HIV-1 (IIIB strain). Molecular modelling and mutagenesis analysis suggested key interactions with an unexplored allosteric site providing insights for the future optimization of this class of RNase H inhibitors.

scholarly journals Effects of the W153L Substitution in HIV Reverse Transcriptase on Viral Replication and Drug Resistance to Multiple Categories of Reverse Transcriptase Inhibitors

2014 ◽  
Vol 58 (8) ◽  
pp. 4515-4526 ◽  
Author(s):  
Hong-Tao Xu ◽  
Susan P. Colby-Germinario ◽  
Maureen Oliveira ◽  
Daniel Rajotte ◽  
Richard Bethell ◽  
...  
Keyword(s):  
Viral Replication ◽  
Reverse Transcriptase ◽  
Rnase H ◽  
Hiv Reverse Transcriptase ◽  
Compound A ◽  
Enzymatic Function ◽  
Biochemical Assays ◽  
Rt Inhibitors ◽  
The Impact ◽  
Hiv 1

ABSTRACTA W153L substitution in HIV-1 reverse transcriptase (RT) was recently identified by selection with a novel nucleotide-competing RT inhibitor (NcRTI) termed compound A that is a member of the benzo[4,5]furo[3,2,d]pyrimidin-2-one NcRTI family of drugs. To investigate the impact of W153L, alone or in combination with the clinically relevant RT resistance substitutions K65R (change of Lys to Arg at position 65), M184I, K101E, K103N, E138K, and Y181C, on HIV-1 phenotypic susceptibility, viral replication, and RT enzymatic function, we generated recombinant RT enzymes and viruses containing each of these substitutions or various combinations of them. We found that W153L-containing viruses were impaired in viral replicative capacity and were hypersusceptible to tenofovir (TFV) while retaining susceptibility to most nonnucleoside RT inhibitors. The nucleoside 3TC retained potency against W153L-containing viruses but not when the M184I substitution was also present. W153L was also able to reverse the effects of the K65R substitution on resistance to TFV, and K65R conferred hypersusceptibility to compound A. Biochemical assays demonstrated that W153L alone or in combination with K65R, M184I, K101E, K103N, E138K, and Y181C impaired enzyme processivity and polymerization efficiency but did not diminish RNase H activity, providing mechanistic insights into the low replicative fitness associated with these substitutions. We show that the mechanism of the TFV hypersusceptibility conferred by W153L is mainly due to increased efficiency of TFV-diphosphate incorporation. These results demonstrate that compound A and/or derivatives thereof have the potential to be important antiretroviral agents that may be combined with tenofovir to achieve synergistic results.

Prediction of the binding mode and resistance profile for a dual-target pyrrolyl diketo acid scaffold against HIV-1 integrase and reverse-transcriptase-associated ribonuclease H

2018 ◽  
Vol 20 (37) ◽  
pp. 23873-23884 ◽  
Author(s):  
Fengyuan Yang ◽  
Guoxun Zheng ◽  
Tingting Fu ◽  
Xiaofeng Li ◽  
Gao Tu ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Binding Mode ◽  
Hiv Treatment ◽  
Rnase H ◽  
Ribonuclease H ◽  
Resistance Profile ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Dual Target

The recently developed pyrrolyl diketo acid scaffold targeting both HIV-1 IN and RNase H is beneficial to counteract the failure of anti-HIV treatment due to drug resistance.

scholarly journals Human Immunodeficiency Virus Type 1 Recombinant Reverse Transcriptase Enzymes Containing the G190A and Y181C Resistance Mutations Remain Sensitive to Etravirine

2009 ◽  
Vol 53 (11) ◽  
pp. 4667-4672 ◽  
Author(s):  
Hongtao Xu ◽  
Yudong Quan ◽  
Bluma G. Brenner ◽  
Tamara Bar-Magen ◽  
Maureen Oliveira ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Resistance Mutations ◽  
Biochemical Assays ◽  
Immunodeficiency Virus ◽  
Drug Resistant Strains ◽  
Hiv 1

ABSTRACT Etravirine (ETR) is a second-generation nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) active against common human immunodeficiency virus type 1 (HIV-1) drug-resistant strains. This study was designed to determine the extent to which each of the Y181C or G190A mutations in RT might confer resistance to ETR and other members of the NNRTI family of drugs. Recombinant HIV-1 RT enzymes containing either the Y181C or the G190A mutation, or both mutations in tandem, were purified. Both RNA- and DNA-dependent DNA polymerase assays were performed in order to determine the extent to which each of these mutations might confer resistance in cell-free biochemical assays against each of ETR, efavirenz, and nevirapine. Both the biochemical and the cell-based phenotypic assays confirmed the susceptibility of G190A-containing enzymes and viruses to ETR. The results of this study indicate that the G190A mutation is not associated with resistance to ETR.

Evaluation of 4-thiazolidinone derivatives as potential reverse transcriptase inhibitors against HIV-1 drug resistant strains

2017 ◽  
Vol 71 ◽  
pp. 211-218 ◽  
Author(s):  
Rahul Suryawanshi ◽  
Sushama Jadhav ◽  
Nandini Makwana ◽  
Dipen Desai ◽  
Devidas Chaturbhuj ◽  
...  
Keyword(s):  
Reverse Transcriptase ◽  
Drug Resistant ◽  
Reverse Transcriptase Inhibitors ◽  
Resistant Strains ◽  
Drug Resistant Strains ◽  
Hiv 1

scholarly journals Selection of Mutations in the Connection and RNase H Domains of Human Immunodeficiency Virus Type 1 Reverse Transcriptase That Increase Resistance to 3′-Azido-3′-Dideoxythymidine

2007 ◽  
Vol 81 (15) ◽  
pp. 7852-7859 ◽  
Author(s):  
Jessica H. Brehm ◽  
Dianna Koontz ◽  
Jeffrey D. Meteer ◽  
Vinay Pathak ◽  
Nicolas Sluis-Cremer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Rnase H ◽  
Cross Resistance ◽  
Polymerase Domain ◽  
Immunodeficiency Virus ◽  
Azt Resistance ◽  
Hiv 1

ABSTRACT Recent work indicates that mutations in the C-terminal domains of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) increase 3′-azido-3′-dideoxythymidine (AZT) resistance. Because it is not known whether AZT selects for mutations outside of the polymerase domain of RT, we carried out in vitro experiments in which HIV-1LAI or AZT-resistant HIV-1LAI (M41L/L210W/T215Y) was passaged in MT-2 cells in increasing concentrations of AZT. The first resistance mutations to appear in HIV-1LAI were two polymerase domain thymidine analog mutations (TAMs), D67N and K70R, and two novel mutations, A371V in the connection domain and Q509L in the RNase H domain, that together conferred up to 90-fold AZT resistance. Thereafter, the T215I mutation appeared but was later replaced by T215F, resulting in a large increase in AZT resistance (∼16,000-fold). Mutations in the connection and RNase H domains were not selected starting with AZT-resistant virus (M41L/L210W/T215Y). The roles of A371V and Q509L in AZT resistance were confirmed by site-directed mutagenesis: A371V and Q509L together increased AZT resistance ∼10- to 50-fold in combination with TAMs (M41L/L210W/T215Y or D67N/K70R/T215F) but had a minimal effect without TAMs (1.7-fold). A371V and Q509L also increased cross-resistance with TAMs to lamivudine and abacavir, but not stavudine or didanosine. These results provide the first evidence that mutations in the connection and RNase H domains of RT can be selected in vitro by AZT and confer greater AZT resistance and cross-resistance to nucleoside RT inhibitors in combination with TAMs in the polymerase domain.

Inhibition of Human Immunodeficiency Virus Type 1 Reverse Transcriptase by Degradation Products of Ceftazidime

1997 ◽  
Vol 8 (4) ◽  
pp. 353-362 ◽  
Author(s):  
SW Baertschi ◽  
AS Cantrell ◽  
MT Kuhfeld ◽  
U Lorenz ◽  
DB Boyd ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Degradation Products ◽  
Rnase H ◽  
Immunodeficiency Virus ◽  
Hiv 1

Previous work by Hafkemeyer et al. (1991) [ Nucleic Acids Research19: 4059–4065] indicated that a degradation product of ceftazidime, termed HP 0.35, was active against the RNase H activity of human immunodeficiency virus type 1 (HIV-1) and feline immunodeficiency virus (FIV) reverse transcriptase (RT) in vitro. Attempting to repeat these results, we isolated HP 0.35 from an aqueous degradation of ceftazidime and, after careful purification, we found HP 0.35 to be essentially inactive against both the polymerase and RNase H domains of HIV-1 RT (IC50 of >100 μg mL−1). During the investigation we discovered that polymeric degradation products of ceftazidime inhibited both the polymerase and, to a greater extent, the RNase H activities of HIV-1 RT in vitro (IC50 approximately 0.1 and 0.01 μg mL−1, respectively). Subjecting HP 0.35 to conditions under which it could polymerize induced inhibitory activity similar to that of the polymeric ceftazidime degradation products. It is proposed that the previously reported activity of HP 0.35 may have resulted from the presence of low levels of polymeric material either from incomplete purification or from polymerization of HP 0.35 during storage or in vitro testing.

scholarly journals Mutations in the U5 Region Adjacent to the Primer Binding Site Affect tRNA Cleavage by Human Immunodeficiency Virus Type 1 Reverse Transcriptase In Vivo

2007 ◽  
Vol 82 (2) ◽  
pp. 719-727 ◽  
Author(s):  
Jangsuk Oh ◽  
Mary Jane McWilliams ◽  
John G. Julias ◽  
Stephen H. Hughes
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Binding Site ◽  
Rnase H ◽  
Primer Binding Site ◽  
Cleavage Specificity ◽  
Immunodeficiency Virus ◽  
Trna Primer ◽  
Hiv 1

ABSTRACT In retroviruses, the first nucleotide added to the tRNA primer defines the end of the U5 region in the right long terminal repeat, and the subsequent removal of this tRNA primer by RNase H exactly defines the U5 end of the linear double-stranded DNA. In most retroviruses, the entire tRNA is removed by RNase H cleavage at the RNA/DNA junction. However, the RNase H domain of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase cleaves the tRNA 1 nucleotide from the RNA/DNA junction at the U5/primer binding site (PBS) junction, which leaves an rA residue at the U5 terminus. We made sequence changes at the end of the U5 region adjacent to the PBS in HIV-1 to determine whether such changes affect the specificity of tRNA primer cleavage by RNase H. In some of the mutants, RNase H usually removed the entire tRNA, showing that the cleavage specificity was shifted by 1 nucleotide. This result suggests that the tRNA cleavage specificity of the HIV-1 RNase domain H depends on sequences in U5.

Transient kinetic analyses of the ribonuclease H cleavage activity of HIV-1 reverse transcriptase in complex with efavirenz and/or a β-thujaplicinol analogue

2013 ◽  
Vol 455 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Brian D. Herman ◽  
Nicolas Sluis-Cremer
Keyword(s):  
Steady State ◽  
Reverse Transcriptase ◽  
Rnase H ◽  
Ribonuclease H ◽  
Cleavage Activity ◽  
Steady State Kinetics ◽  
Hiv 1

Pre-steady-state kinetics were used to define the mechanisms by which efavirenz and a β-thujaplicinol analogue modulate the RNase H activity of HIV-1 reverse transcriptase. Both inhibitors do not affect polymerase-dependent cleavages, but significantly affect the rates of polymerase-independent cleavages.

Synthesis and evaluation of potent human immunodeficiency virus 1 protease inhibitors with epimeric isopropanol as novel P1′ ligands

2020 ◽  
Vol 12 (9) ◽  
pp. 775-794 ◽  
Author(s):  
Mei Zhu ◽  
Ling Ma ◽  
Biao Dong ◽  
Guoning Zhang ◽  
Juxian Wang ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Design Strategy ◽  
Drug Resistant ◽  
Inhibition Activity ◽  
Protease Enzyme ◽  
Immunodeficiency Virus ◽  
Resistant Strains ◽  
Backbone Atoms ◽  
Drug Resistant Strains ◽  
Hiv 1

Aim: HIV-1 protease inhibitors regimens suffered from a number of drawbacks, among which, the most egregious issue was the growing emergence of drug-resistant strains. Materials & methods: The design strategy of maximizing the protease active site interactions with the inhibitor, especially promoting extensive hydrogen bonding with the protein backbone atoms, might be in favor of combating drug resistance. A series of HIV-1 protease inhibitors that incorporated enantiomeric isopropanols as the P1′ ligands in combination with phenols as the P2 ligands were reported herein. Results: A number of inhibitors displayed potent protease enzyme inhibition activity. In particular, inhibitor 14c showed comparable potency as darunavir with IC50 value of 1.91 nM and activity against darunavir-resistant HIV-1 variants. Conclusion: The new kind of HIV-1 protease inhibitors deserves further study.

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