scholarly journals An inhibitor-interaction intermediate of HIV-1 protease, revealed by Isothermal Titration Calorimetry and NMR spectroscopy

2018 ◽  
Author(s):  
Shahid N Khan ◽  
John D Persons ◽  
Michel Guerrero ◽  
Tatiana V. Ilina ◽  
Masayuki Oda ◽  
...  
Keyword(s):  
Heat Flow ◽  
Isothermal Titration Calorimetry ◽  
Titration Calorimetry ◽  
Drug Resistant ◽  
Wild Type ◽  
Binding Experiment ◽  
Direct Experiment ◽  
Resistant Mutants ◽  
Inhibitor Interaction ◽  
Hiv 1

AbstractSome of drug-resistant mutants of HIV-1 protease (PR), such as a clinically-relevant drug- resistant PR mutant (Flap+(I54V)) containing L10I, G48V, I54V and V82A mutations, produce significant changes in the balance between entropy and enthalpy of the drug-PR interactions, compared to the wild-type (WT) PR. Here, to gain a comprehensive understanding of the entropy-enthalpy compensation effects, we compared nuclear magnetic resonance (NMR), fluorescence spectroscopy and isothermal titration calorimetry (ITC) data of a WT PR with Flap+(I54V)and related mutants: (1) Flap+(I54V); (2) Flap+(I54A)which evolves from Flap+(I54V)in the continued presence of inhibitor yet does not exhibit entropy-enthalpy compensation; and (3) Flap+(I54), a control mutant that contains only L10I, G48V and V82A mutations. Our data indicate that WT and Flap+(I54A)show enthalpy-driven inhibitor-interaction, while Flap+(I54)and Flap+(I54V)exhibit entropy-driven inhibitor interaction. Interestingly, Flap+(I54A)exhibited significantly slower heat flow in the competitive ITC experiment with a strong binder, darunavir, and a weak binder, acetyl-pepstatin, but did not exhibit such slow heat flow in the direct inhibitor-titration experiments. NMR confirmed replacement of the weak binder by the strong binder in a competitive manner. This difference in the heat flow of the competitive binding experiment compared to the direct experiment can only be explained by assuming an inhibitor-bound intermediate pathway. A similar, but attenuated, tendency for slow heat flow was also detected in the competitive experiment with WT. Overall, our data suggests that an inhibitor-bound intermediate affects the entropy-enthalpy compensation of inhibitor-PR interaction.

scholarly journals Potent New Antiviral Compound Shows Similar Inhibition and Structural Interactions with Drug Resistant Mutants and Wild Type HIV-1 Protease†

2007 ◽  
Vol 50 (18) ◽  
pp. 4509-4515 ◽  
Author(s):  
Yuan-Fang Wang ◽  
Yunfeng Tie ◽  
Peter I. Boross ◽  
Jozsef Tozser ◽  
Arun K. Ghosh ◽  
...  
Keyword(s):  
Drug Resistant ◽  
Wild Type ◽  
Antiviral Compound ◽  
Structural Interactions ◽  
Resistant Mutants ◽  
Hiv 1

Enantioselective binding of second generation pyrrolobenzoxazepinones to the catalytic ternary complex of HIV-1 RT wild-type and L100I and K103N drug resistant mutants

2011 ◽  
Vol 21 (13) ◽  
pp. 3935-3938 ◽  
Author(s):  
Stefania Butini ◽  
Sandra Gemma ◽  
Margherita Brindisi ◽  
Giuseppe Borrelli ◽  
Isabella Fiorini ◽  
...  
Keyword(s):  
Ternary Complex ◽  
Second Generation ◽  
Drug Resistant ◽  
Wild Type ◽  
Resistant Mutants ◽  
Hiv 1

scholarly journals Competitive Fitness of Nevirapine-Resistant Human Immunodeficiency Virus Type 1 Mutants

2004 ◽  
Vol 78 (2) ◽  
pp. 603-611 ◽  
Author(s):  
Jennifer A. Collins ◽  
M. Gregory Thompson ◽  
Elijah Paintsil ◽  
Melisa Ricketts ◽  
Joanna Gedzior ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Drug Resistant ◽  
Wild Type ◽  
Competitive Fitness ◽  
Immunodeficiency Virus ◽  
Resistant Mutants ◽  
Nevirapine Resistance ◽  
Hiv 1

ABSTRACT Determining the fitness of drug-resistant human immunodeficiency virus type 1 (HIV-1) strains is necessary for the development of population-based studies of resistance patterns. For this purpose, we have developed a reproducible, systematic assay to determine the competitive fitness of HIV-1 drug-resistant mutants. To demonstrate the applicability of this assay, we tested the fitness of the five most common nevirapine-resistant mutants (103N, 106A, 181C, 188C, and 190A), with mutations in HIV-1 reverse transcriptase (RT), singly and in combination (for a total of 31 variants) in a defined HIV-1 background. For these experiments, the 27 RT variants that produced viable virus were cocultured with wild-type virus without nevirapine. The ratios of the viral species were determined over time by utilization of a quantitative real-time RT-PCR-based assay. These experiments revealed that all of the viable variants were less fit than the wild type and demonstrated that the order of relative fitness of the single mutants tested was as follows: 103N > 181C > 190A > 188C > 106A. This order correlated with the commonality of these mutants as a result of nevirapine monotherapy. These investigations also revealed that, on average, the double mutants were less fit than the single mutants and the triple mutants were less fit than the double mutants. However, the fitness of the single and double mutants was often not predictive of the fitness of the derivative triple mutants, suggesting the presence of complex interactions between the closely aligned residues that confer nevirapine resistance. This complexity was also evident from the observation that all three of the replication-competent quadruple mutants were fitter than most of the triple mutants, and in some cases, even the double mutants. Our data suggest that, in many cases, viral fitness is the determining factor in the evolution of nevirapine-resistant mutants in vivo, that interactions between the residues that confer nevirapine resistance are complex, and that these interactions substantially affect reverse transcriptase structure and/or function.

scholarly journals Novel Single-Cell-Level Phenotypic Assay for Residual Drug Susceptibility and Reduced Replication Capacity of Drug-Resistant Human Immunodeficiency Virus Type 1

2004 ◽  
Vol 78 (4) ◽  
pp. 1718-1729 ◽  
Author(s):  
Haili Zhang ◽  
Yan Zhou ◽  
Cecily Alcock ◽  
Tara Kiefer ◽  
Daphne Monie ◽  
...  
Keyword(s):  
Drug Combination ◽  
Wild Type Virus ◽  
Replication Capacity ◽  
Drug Resistant ◽  
Type Virus ◽  
Wild Type ◽  
Cell Level ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-infected individuals who develop drug-resistant virus during antiretroviral therapy may derive benefit from continued treatment for two reasons. First, drug-resistant viruses can retain partial susceptibility to the drug combination. Second, therapy selects for drug-resistant viruses that may have reduced replication capacities relative to archived, drug-sensitive viruses. We developed a novel single-cell-level phenotypic assay that allows these two effects to be distinguished and compared quantitatively. Patient-derived gag-pol sequences were cloned into an HIV-1 reporter virus that expresses an endoplasmic reticulum-retained Env-green fluorescent protein fusion. Flow cytometric analysis of single-round infections allowed a quantitative analysis of viral replication over a 4-log dynamic range. The assay faithfully reproduced known in vivo drug interactions occurring at the level of target cells. Simultaneous analysis of single-round infections by wild-type and resistant viruses in the presence and absence of the relevant drug combination divided the benefit of continued nonsuppressive treatment into two additive components, residual virus susceptibility to the drug combination and selection for drug-resistant variants with diminished replication capacities. In some patients with drug resistance, the dominant circulating viruses retained significant susceptibility to the combination. However, in other cases, the dominant drug-resistant viruses showed no residual susceptibility to the combination but had a reduced replication capacity relative to the wild-type virus. In this case, simplification of the regimen might still allow adequate suppression of the wild-type virus. In a third pattern, the resistant viruses had no residual susceptibility to the relevant drug regimen but nevertheless had a replication capacity equivalent to that of wild-type virus. In such cases, there is no benefit to continued treatment. Thus, the ability to simultaneously analyze residual susceptibility and reduced replication capacity of drug-resistant viruses may provide a basis for rational therapeutic decisions in the setting of treatment failure.

Prevalence of drug resistant mutants and virological response to combination therapy in patients with primary HIV-1 infection

2000 ◽  
Vol 61 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Catherine Tamalet ◽  
Christophe Pasquier ◽  
Nouara Yahi ◽  
Philippe Colson ◽  
Isabelle Poizot-Martin ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Virological Response ◽  
Drug Resistant ◽  
Resistant Mutants ◽  
Hiv 1

Clade B HIV-1 superinfection with wild-type virus after primary infection with drug-resistant clade B virus

AIDS ◽  
2003 ◽  
Vol 17 (7) ◽  
pp. F11-F16 ◽  
Author(s):  
Kersten K Koelsch ◽  
Davey M Smith ◽  
Susan J Little ◽  
Caroline C Ignacio ◽  
Theresa R Macaranas ◽  
...  
Keyword(s):  
Primary Infection ◽  
Wild Type Virus ◽  
Drug Resistant ◽  
Type Virus ◽  
Wild Type ◽  
Clade B ◽  
B Virus ◽  
Hiv 1

scholarly journals High Potency of Indolyl Aryl Sulfone Nonnucleoside Inhibitors towards Drug-Resistant Human Immunodeficiency Virus Type 1 Reverse Transcriptase Mutants Is Due to Selective Targeting of Different Mechanistic Forms of the Enzyme

2005 ◽  
Vol 49 (11) ◽  
pp. 4546-4554 ◽  
Author(s):  
Reynel Cancio ◽  
Romano Silvestri ◽  
Rino Ragno ◽  
Marino Artico ◽  
Gabriella De Martino ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Mechanism Of Action ◽  
Drug Resistant ◽  
Wild Type ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Indolyl aryl sulfone (IAS) nonnucleoside inhibitors have been shown to potently inhibit the growth of wild-type and drug-resistant human immunodeficiency virus type 1 (HIV-1), but their exact mechanism of action has not been elucidated yet. Here, we describe the mechanism of inhibition of HIV-1 reverse transcriptase (RT) by selected IAS derivatives. Our results showed that, depending on the substitutions introduced in the IAS common pharmacophore, these compounds can be made selective for different enzyme-substrate complexes. Moreover, we showed that the molecular basis for this selectivity was a different association rate of the drug to a particular enzymatic form along the reaction pathway. By comparing the activities of the different compounds against wild-type RT and the nonnucleoside reverse transcriptase inhibitor-resistant mutant Lys103Asn, it was possible to hypothesize, on the basis of their mechanism of action, a rationale for the design of drugs which could overcome the steric barrier imposed by the Lys103Asn mutation.

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