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El Khoury L, El Hage K, Piquemal JP, Fermandjian S, Maroun RG, Gresh N, Hobaika Z. Spectrometric and computational studies of the binding of HIV-1 integrase inhibitors to viral DNA extremities. PEERJ PHYSICAL CHEMISTRY 2019. [DOI: 10.7717/peerj-pchem.6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Three integrase strand transfer inhibitors are in intensive clinical use, raltegravir (RAL), elvitegravir (EVG) and dolutegravir (DTG). The onset of integrase resistance mutations limits their therapeutic efficiency. As put forth earlier, the drug affinity for the intasome could be improved by targeting preferentially the retroviral nucleobases, which are little, if at all, mutation-prone. We report experimental results of anisotropy fluorescence titrations of viral DNA by these three drugs. These show the DTG > EVG > RAL ranking of their inhibitory activities of the intasome to correspond to that of their free energies of binding, ∆Gs, to retroviral DNA, and that such a ranking is only governed by the binding enthalpies, ∆H, the entropy undergoing marginal variations. We sought whether this ranking might be reproduced through quantum chemistry (QC) Density Functional Theory calculations of intermolecular interaction energies between simplified models consisting of sole halobenzene ring and the highly conserved retroviral nucleobases G4 and C16. These calculations showed that binding of EVG has a small preference over DTG, while RAL ranked third. This indicates that additional interactions of the diketoacid parts of the drugs with DNA could be necessary to further enable preferential binding of DTG. The corresponding ∆Etotvalues computed with a polarizable molecular mechanics/dynamics procedure, Sum of Interactions Between Fragments Ab initio computed (SIBFA), showed good correlations with this ∆E(QC) ranking. These validations are an important step toward the use of polarizable molecular dynamics simulations on DTG or EVG derivatives in their complexes with the complete intasome, an application now motivated and enabled by the advent of currently developed and improved massively parallel software.
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Affiliation(s)
- Léa El Khoury
- Laboratoire de Chimie Théorique, UMR7616 CNRS, Sorbonne Université, Paris, France
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Present address: Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, USA
| | - Krystel El Hage
- Chemistry and Biology Nucleo(s)tides and Immunology for Therapy (CBNIT), UMR 8601 CNRS, UFR Biomedicale, Paris, France
- Present address: Laboratoire Structure-Activité des Biomolécules Normales et Pathologiques, INSERM U829, Université Evry-Val d’Essonne, Evry, France
| | - Jean-Philip Piquemal
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
- Institut Universitaire de France, Paris, France
| | - Serge Fermandjian
- Chemistry and Biology Nucleo(s)tides and Immunology for Therapy (CBNIT), UMR 8601 CNRS, UFR Biomedicale, Paris, France
| | - Richard G. Maroun
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
| | - Nohad Gresh
- Laboratoire de Chimie Théorique, UMR7616 CNRS, Sorbonne Université, Paris, France
| | - Zeina Hobaika
- UR EGP, Centre d’Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
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Probing Resistance Mutations in Retroviral Integrases by Direct Measurement of Dolutegravir Fluorescence. Sci Rep 2017; 7:14067. [PMID: 29070877 PMCID: PMC5656594 DOI: 10.1038/s41598-017-14564-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/11/2017] [Indexed: 12/12/2022] Open
Abstract
FDA-approved integrase strand transfer inhibitors (raltegravir, elvitegravir and dolutegravir) efficiently inhibit HIV-1 replication. Here, we present fluorescence properties of these inhibitors. Dolutegravir displays an excitation mode particularly dependent on Mg2+ chelation, allowing to directly probe its Mg2+-dependent binding to the prototype foamy virus (PFV) integrase. Dolutegravir-binding studied by both its fluorescence anisotropy and subsequent emission enhancement, strictly requires a preformed integrase/DNA complex, the ten terminal base pairs from the 3′-end of the DNA reactive strand being crucial to optimize dolutegravir-binding in the context of the ternary complex. From the protein side, mutation of any catalytic residue fully abolishes dolutegravir-binding. We also compared dolutegravir-binding to PFV F190Y, G187R and S217K mutants, corresponding to HIV-1 F121Y, G118R and G140S/Q148K mutations that confer low-to-high resistance levels against raltegravir/dolutegravir. The dolutegravir-binding properties derived from fluorescence-based binding assays and drug susceptibilities in terms of catalytic activity, are well correlated. Indeed, dolutegravir-binding to wild-type and F190Y integrases are comparable while strongly compromised with G187R and S217K. Accordingly, the two latter mutants are highly resistant to dolutegravir while F190Y shows only moderate or no resistance. Intrinsic fluorescence properties of dolutegravir are thus particularly suitable for a thorough characterization of both DNA-binding properties of integrase and resistance mutations.
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El Khoury L, Piquemal JP, Fermandjian S, Maroun RG, Gresh N, Hobaika Z. The inhibition process of HIV-1 integrase by diketoacids molecules: Understanding the factors governing the better efficiency of dolutegravir. Biochem Biophys Res Commun 2017; 488:433-438. [PMID: 28478035 DOI: 10.1016/j.bbrc.2017.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/01/2017] [Indexed: 01/03/2023]
Abstract
The Human Immunodeficiency Virus-1 integrase is responsible for the covalent insertion of a newly synthesized double-stranded viral DNA into the host cells, and is an emerging target for antivirus drug design. Raltegravir (RAL) and elvitegravir (EVG) are the first two integrase strand transfer inhibitors used in therapy. However, treated patients eventually develop detrimental resistance mutations. By contrast, a recently approved drug, dolutegravir (DTG), presents a high barrier to resistance. This study aims to understand the increased efficiency of DTG upon focusing on its interaction properties with viral DNA. The results showed DTG to be involved in more extended interactions with viral DNA than EVG. Such interactions involve the halobenzene and scaffold of DTG and EVG and bases 5'G-43', 3'A35'and 3'C45'.
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Affiliation(s)
- Léa El Khoury
- UR EGP, Centre d'Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon; Laboratoire de Chimie Théorique, UMR7616 CNRS, UPMC, Sorbonne Universités, Paris 75005, France.
| | - Jean-Philip Piquemal
- Laboratoire de Chimie Théorique, UMR7616 CNRS, UPMC, Sorbonne Universités, Paris 75005, France; Institut Universitaire de France, Paris Cedex 05, 75231, France; Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712, United States.
| | - Serge Fermandjian
- Chemistry and Biology Nucleo(S)Tides and Immunology for Therapy (CBNIT), UMR 8601 CNRS, UFR Biomédicale, Paris, France.
| | - Richard G Maroun
- UR EGP, Centre d'Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon.
| | - Nohad Gresh
- Laboratoire de Chimie Théorique, UMR7616 CNRS, UPMC, Sorbonne Universités, Paris 75005, France.
| | - Zeina Hobaika
- UR EGP, Centre d'Analyses et de Recherche, Faculté des Sciences, Université Saint-Joseph de Beyrouth, B.P. 11-514 Riad El Solh, Beirut 1107 2050, Lebanon.
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Ammar FF, Hobaika Z, Abdel-Azeim S, Zargarian L, Maroun RG, Fermandjian S. A targeted DNA substrate mechanism for the inhibition of HIV-1 integrase by inhibitors with antiretroviral activity. FEBS Open Bio 2016; 6:234-50. [PMID: 27239438 PMCID: PMC4821353 DOI: 10.1002/2211-5463.12025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/25/2015] [Accepted: 12/16/2015] [Indexed: 12/21/2022] Open
Abstract
We recently reported that viral DNA could be the primary target of raltegravir (RAL), an efficient anti‐HIV‐1 drug, which acts by inhibiting integrase. To elucidate this mechanism, we conducted a comparative analysis of RAL and TB11, a diketoacid abandoned as an anti‐HIV‐1 drug for its weak efficiency and marked toxicity, and tested the effects of the catalytic cofactor Mg2+ (5 mm) on drug‐binding properties. We used circular dichroism and fluorescence to determine drug affinities for viral DNA long terminal repeats (LTRs) and peptides derived from the integrase active site and DNA retardation assays to assess drug intercalation into DNA base pairs. We found that RAL bound more tightly to LTR ends than did TB11 (a diketo acid bearing an azido group) and that Mg2+ significantly increased the affinity of both RAL and TB11. We also observed a good relationship between drug binding with processed LTR and strand transfer inhibition. This unusual type of inhibition was caused by Mg2+‐assisted binding of drugs to DNA substrate, rather than to enzyme. Notably, while RAL bound exclusively to the cleavable/cleaved site, TB11 further intercalated into DNA base pairs and interacted with the integrase‐derived peptides. These unwanted binding sites explain the weaker bioavailability and higher toxicity of TB11 compared with the more effective RAL.
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Affiliation(s)
- Farah F Ammar
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon; LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Zeina Hobaika
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon
| | - Safwat Abdel-Azeim
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Loussinée Zargarian
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France
| | - Richard G Maroun
- Centre d'Analyses et de Recherche UR EGFEM Faculté des Sciences Université Saint-Joseph Beirut Lebanon
| | - Serge Fermandjian
- LBPA, UMR8113 du CNRS Ecole Normale Supérieure de Cachan Cedex Cachan France; Chemistry and Biology, Nucleo(s)tides and Immunology for Therapy UMR8601 CNRS Paris Cedex 06 France
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Abstract
HIV integrase (IN) catalyzes the insertion into the genome of the infected human cell of viral DNA produced by the retrotranscription process. The discovery of raltegravir validated the existence of the IN, which is a new target in the field of anti-HIV drug research. The mechanism of catalysis of IN is depicted, and the characteristics of the inhibitors of the catalytic site of this viral enzyme are reported. The role played by the resistance is elucidated, as well as the possibility of bypassing this problem. New approaches to block the integration process are depicted as future perspectives, such as development of allosteric IN inhibitors, dual inhibitors targeting both IN and other enzymes, inhibitors of enzymes that activate IN, activators of IN activity, as well as a gene therapy approach.
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Affiliation(s)
- Roberto Di Santo
- Dipartimento
di Chimica e
Tecnologie del Farmaco, Istituto Pasteur, Fondazione Cenci Bolognetti, “Sapienza” Università di Roma, P.le Aldo Moro 5, I-00185 Rome, Italy
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Abstract
HIV integrase (IN) catalyzes the insertion into the genome of the infected human cell of viral DNA produced by the retrotranscription process. The discovery of raltegravir validated the existence of the IN, which is a new target in the field of anti-HIV drug research. The mechanism of catalysis of IN is depicted, and the characteristics of the inhibitors of the catalytic site of this viral enzyme are reported. The role played by the resistance is elucidated, as well as the possibility of bypassing this problem. New approaches to block the integration process are depicted as future perspectives, such as development of allosteric IN inhibitors, dual inhibitors targeting both IN and other enzymes, inhibitors of enzymes that activate IN, activators of IN activity, as well as a gene therapy approach.
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Affiliation(s)
- Roberto Di Santo
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur, Fondazione Cenci Bolognetti, "Sapienza" Università di Roma , P.le Aldo Moro 5, I-00185 Rome, Italy
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Chen Q, Buolamwini JK, Smith JC, Li A, Xu Q, Cheng X, Wei D. Impact of resistance mutations on inhibitor binding to HIV-1 integrase. J Chem Inf Model 2013; 53:3297-307. [PMID: 24205814 DOI: 10.1021/ci400537n] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
HIV-1 integrase (IN) is essential for HIV-1 replication, catalyzing two key reaction steps termed 3' processing and strand transfer. Therefore, IN has become an important target for antiviral drug discovery. However, mutants have emerged, such as E92Q/N155H and G140S/Q148H, which confer resistance to raltegravir (RAL), the first IN strand transfer inhibitor (INSTI) approved by the FDA, and to the recently approved elvitegravir (EVG). To gain insights into the molecular mechanisms of ligand binding and drug resistance, we performed molecular dynamics (MD) simulations of homology models of the HIV-1 IN and four relevant mutants complexed with viral DNA and RAL. The results show that the structure and dynamics of the 140s' loop, comprising residues 140 to 149, are strongly influenced by the IN mutations. In the simulation of the G140S/Q148H double mutant, we observe spontaneous dissociation of RAL from the active site, followed by an intrahelical swing-back of the 3'-OH group of nucleotide A17, consistent with the experimental observation that the G140S/Q148H mutant exhibits the highest resistance to RAL compared to other IN mutants. An important hydrogen bond between residues 145 and 148 is present in the wild-type IN but not in the G140S/Q148H mutant, accounting for the structural and dynamical differences of the 140s' loop and ultimately impairing RAL binding in the double mutant. End-point free energy calculations that broadly capture the experimentally known RAL binding profiles elucidate the contributions of the 140s' loop to RAL binding free energies and suggest possible approaches to overcoming drug resistance.
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Affiliation(s)
- Qi Chen
- State Key Laboratory of Microbial Metabolism and College of Life Science and Biotechnology, Shanghai Jiao Tong University , Shanghai 200240, China
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Arora R, de Beauchene IC, Polanski J, Laine E, Tchertanov L. Raltegravir flexibility and its impact on recognition by the HIV-1 IN targets. J Mol Recognit 2013; 26:383-401. [PMID: 23836466 DOI: 10.1002/jmr.2277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 04/04/2013] [Accepted: 04/07/2013] [Indexed: 01/10/2023]
Abstract
HIV-1 IN is a pertinent target for the development of AIDS chemotherapy. The first IN-specific inhibitor approved for the treatment of HIV/AIDS, RAL, was designed to block the ST reaction. We characterized the structural and conformational features of RAL and its recognition by putative HIV-1 targets - the unbound IN, the vDNA, and the IN•vDNA complex - mimicking the IN states over the integration process. RAL binding to the targets was studied by performing an extensive sampling of the inhibitor conformational landscape and by using four different docking algorithms: Glide, Autodock, VINA, and SurFlex. The obtained data evidenced that: (i) a large binding pocket delineated by the active site and an extended loop in the unbound IN accommodates RAL in distinct conformational states all lacking specific interactions with the target; (ii) a well-defined cavity formed by the active site, the vDNA, and the shortened loop in the IN•vDNA complex provide a more optimized inhibitor binding site in which RAL chelates Mg(2+) cations; (iii) a specific recognition between RAL and the unpaired cytosine of the processed DNA is governed by a pair of strong H-bonds similar to those observed in DNA base pair G-C. The identified RAL pose at the cleaved vDNA shed light on a putative step of RAL inhibition mechanism. This modeling study indicates that the inhibition process may include as a first step RAL recognition by the processed vDNA bound to a transient intermediate IN state, and thus provides a potentially promising route to the design of IN inhibitors with improved affinity and selectivity.
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Affiliation(s)
- Rohit Arora
- Bioinformatics, Molecular Dynamics & Modeling (BiMoDyM), Laboratoire de Biologie et Pharmacologie Appliquée (LBPA-CNRS), Ecole Normale Supérieure de Cachan, 61 avenue du Président Wilson, 94235, Cachan, France
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