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Hybrid Molecules as Potential Drugs for the Treatment of HIV: Design and Applications. Pharmaceuticals (Basel) 2022; 15:ph15091092. [PMID: 36145313 PMCID: PMC9502546 DOI: 10.3390/ph15091092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 08/23/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022] Open
Abstract
Human immunodeficiency virus (HIV) infection is a major problem for humanity because HIV is constantly changing and developing resistance to current drugs. This necessitates the development of new anti-HIV drugs that take new approaches to combat an ever-evolving virus. One of the promising alternatives to combination antiretroviral therapy (cART) is the molecular hybrid strategy, in which two or more pharmacophore units of bioactive scaffolds are combined into a single molecular structure. These hybrid structures have the potential to have higher efficacy and lower toxicity than their parent molecules. Given the potential advantages of the hybrid molecular approach, the development and synthesis of these compounds are of great importance in anti-HIV drug discovery. This review focuses on the recent development of hybrid compounds targeting integrase (IN), reverse transcriptase (RT), and protease (PR) proteins and provides a brief description of their chemical structures, structure–activity relationship, and binding mode.
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Abstract
The introduction of antiretroviral therapy (ART) and highly active antiretroviral therapy (HAART) has transformed human immunodeficiency virus (HIV)-1 into a chronic, well-managed disease. However, these therapies do not eliminate all infected cells from the body despite suppressing viral load. Viral rebound is largely due to the presence of cellular reservoirs which support long-term persistence of HIV-1. A thorough understanding of the HIV-1 reservoir will facilitate the development of new strategies leading to its detection, reduction, and elimination, ultimately leading to curative therapies for HIV-1. Although immune cells derived from lymphoid and myeloid progenitors have been thoroughly studied as HIV-1 reservoirs, few studies have examined whether mesenchymal stromal/stem cells (MSCs) can assume this function. In this review, we evaluate published studies which have assessed whether MSCs contribute to the HIV-1 reservoir. MSCs have been found to express the receptors and co-receptors required for HIV-1 entry, albeit at levels of expression and receptor localisation that vary considerably between studies. Exposure to HIV-1 and HIV-1 proteins alters MSC properties in vitro, including their proliferation capacity and differentiation potential. However, in vitro and in vivo experiments investigating whether MSCs can become infected with and harbour latent integrated proviral DNA are lacking. In conclusion, MSCs appear to have the potential to contribute to the HIV-1 reservoir. However, further studies are needed using techniques such as those used to prove that cluster of differentiation (CD)4+ T cells constitute an HIV-1 reservoir before a reservoir function can definitively be ascribed to MSCs.
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Sherry D, Worth R, Sayed Y. Elasticity-Associated Functionality and Inhibition of the HIV Protease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1371:79-108. [PMID: 34351572 DOI: 10.1007/5584_2021_655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
HIV protease plays a critical role in the life cycle of the virus through the generation of mature and infectious virions. Detailed knowledge of the structure of the enzyme and its substrate has led to the development of protease inhibitors. However, the development of resistance to all currently available protease inhibitors has contributed greatly to the decreased success of antiretroviral therapy. When therapy failure occurs, multiple mutations are found within the protease sequence starting with primary mutations, which directly impact inhibitor binding, which can also negatively impact viral fitness and replicative capacity by decreasing the binding affinity of the natural substrates to the protease. As such, secondary mutations which are located outside of the active site region accumulate to compensate for the recurrently deleterious effects of primary mutations. However, the resistance mechanism of these secondary mutations is not well understood, but what is known is that these secondary mutations contribute to resistance in one of two ways, either through increasing the energetic penalty associated with bringing the protease into the closed conformation, or, through decreasing the stability of the protein/drug complex in a manner that increases the dissociation rate of the drug, leading to diminished inhibition. As a result, the elasticity of the enzyme-substrate complex has been implicated in the successful recognition and catalysis of the substrates which may be inferred to suggest that the elasticity of the enzyme/drug complex plays a role in resistance. A realistic representation of the dynamic nature of the protease may provide a more powerful tool in structure-based drug design algorithms.
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Affiliation(s)
- Dean Sherry
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Roland Worth
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Yasien Sayed
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa.
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4
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Combining Molecular Dynamic Information and an Aspherical-Atom Data Bank in the Evaluation of the Electrostatic Interaction Energy in Multimeric Protein-Ligand Complex: A Case Study for HIV-1 Protease. Molecules 2021; 26:molecules26133872. [PMID: 34202892 PMCID: PMC8270314 DOI: 10.3390/molecules26133872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/19/2021] [Accepted: 06/22/2021] [Indexed: 11/23/2022] Open
Abstract
Computational analysis of protein–ligand interactions is of crucial importance for drug discovery. Assessment of ligand binding energy allows us to have a glimpse of the potential of a small organic molecule to be a ligand to the binding site of a protein target. Available scoring functions, such as in docking programs, all rely on equations that sum each type of protein–ligand interactions in order to predict the binding affinity. Most of the scoring functions consider electrostatic interactions involving the protein and the ligand. Electrostatic interactions constitute one of the most important part of total interactions between macromolecules. Unlike dispersion forces, they are highly directional and therefore dominate the nature of molecular packing in crystals and in biological complexes and contribute significantly to differences in inhibition strength among related enzyme inhibitors. In this study, complexes of HIV-1 protease with inhibitor molecules (JE-2147 and darunavir) were analyzed by using charge densities from the transferable aspherical-atom University at Buffalo Databank (UBDB). Moreover, we analyzed the electrostatic interaction energy for an ensemble of structures, using molecular dynamic simulations to highlight the main features of electrostatic interactions important for binding affinity.
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5
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Abdelsattar AS, Dawoud A, Helal MA. Interaction of nanoparticles with biological macromolecules: a review of molecular docking studies. Nanotoxicology 2020; 15:66-95. [PMID: 33283572 DOI: 10.1080/17435390.2020.1842537] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The high frequency of using engineered nanoparticles in various medical applications entails a deep understanding of their interaction with biological macromolecules. Molecular docking simulation is now widely used to study the binding of different types of nanoparticles with proteins and nucleic acids. This helps not only in understanding the mechanism of their biological action but also in predicting any potential toxicity. In this review, the computational techniques used in studying the nanoparticles interaction with biological macromolecules are covered. Then, a comprehensive overview of the docking studies performed on various types of nanoparticles will be offered. The implication of these predicted interactions in the biological activity and/or toxicity is also discussed for each type of nanoparticles.
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Affiliation(s)
- Abdallah S Abdelsattar
- Center for X-Ray and Determination of Structure of Matter, Zewail City of Science and Technology, Giza, Egypt
| | - Alyaa Dawoud
- Faculty of Pharmacy and Biotechnology, German University in Cairo, Cairo, Egypt
| | - Mohamed A Helal
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt.,Medicinal Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
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6
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Lawal MM, Sanusi ZK, Govender T, Maguire GE, Honarparvar B, Kruger HG. From Recognition to Reaction Mechanism: An Overview on the Interactions between HIV-1 Protease and its Natural Targets. Curr Med Chem 2020; 27:2514-2549. [DOI: 10.2174/0929867325666181113122900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 11/04/2018] [Accepted: 11/07/2018] [Indexed: 12/28/2022]
Abstract
Current investigations on the Human Immunodeficiency Virus Protease (HIV-1
PR) as a druggable target towards the treatment of AIDS require an update to facilitate further
development of promising inhibitors with improved inhibitory activities. For the past two
decades, up to 100 scholarly reports appeared annually on the inhibition and catalytic mechanism
of HIV-1 PR. A fundamental literature review on the prerequisite of HIV-1 PR action
leading to the release of the infectious virion is absent. Herein, recent advances (both computationally
and experimentally) on the recognition mode and reaction mechanism of HIV-1 PR
involving its natural targets are provided. This review features more than 80 articles from
reputable journals. Recognition of the natural Gag and Gag-Pol cleavage junctions by this
enzyme and its mutant analogs was first addressed. Thereafter, a comprehensive dissect of
the enzymatic mechanism of HIV-1 PR on its natural polypeptide sequences from literature
was put together. In addition, we highlighted ongoing research topics in which in silico
methods could be harnessed to provide deeper insights into the catalytic mechanism of the
HIV-1 protease in the presence of its natural substrates at the molecular level. Understanding
the recognition and catalytic mechanism of HIV-1 PR leading to the release of an infective
virion, which advertently affects the immune system, will assist in designing mechanismbased
inhibitors with improved bioactivity.
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Affiliation(s)
- Monsurat M. Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Zainab K. Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Glenn E.M. Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
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Perico L, Benigni A, Remuzzi G. Should COVID-19 Concern Nephrologists? Why and to What Extent? The Emerging Impasse of Angiotensin Blockade. Nephron Clin Pract 2020; 144:213-221. [PMID: 32203970 PMCID: PMC7179544 DOI: 10.1159/000507305] [Citation(s) in RCA: 198] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 01/08/2023] Open
Abstract
Here, we review the most recent findings on the effects of SARS-CoV-2 infection on kidney diseases, including acute kidney injury, and examine the potential effects of ARBs on the outcomes of patients with COVID-19. Lastly, we discuss the clinical management of COVID-19 patients with existing chronic renal disorders, particularly those in dialysis and with kidney transplants.
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Affiliation(s)
- Luca Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy,
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy,
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8
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Paim AC, Badley AD, Cummins NW. Mechanisms of Human Immunodeficiency Virus-Associated Lymphocyte Regulated Cell Death. AIDS Res Hum Retroviruses 2020; 36:101-115. [PMID: 31659912 PMCID: PMC7044792 DOI: 10.1089/aid.2019.0213] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus-1 (HIV-1) causes CD4 T cell depletion through a number of mechanisms, including programmed cell death pathways (both apoptotic and nonapoptotic). In the setting of HIV-1 infection, the enhanced lymphocyte cell death occurs as a consequence of complex interactions between the host immune system and viral factors, which are reviewed herein. On the other hand, the main challenge to HIV-1 eradication is the development of latent infection in a subset of long lived cells, including CD4+ T cells and macrophages, which resist HIV-induced cell death. Understanding the potential mechanisms of how HIV-1 induces lymphocyte cell death is critical to the "kick and kill" cure strategy, which relies on the effective killing of reactivated, HIV-1-infected cells.
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Affiliation(s)
- Ana C. Paim
- Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota
| | - Andrew D. Badley
- Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota
- Department of Molecular Medicine, Mayo Clinic, Rochester, Minnesota
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9
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Kim H, Lee SY, Choi YM, Kim BJ. HBV polymerase-derived peptide exerts an anti-HIV-1 effect by inhibiting the acetylation of viral integrase. Biochem Biophys Res Commun 2018; 501:541-546. [PMID: 29752938 DOI: 10.1016/j.bbrc.2018.05.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 05/04/2018] [Indexed: 02/06/2023]
Abstract
Here, we found that a 6-mer peptide, Poly6, derived from the hepatitis B virus (HBV), which overlaps with a polymerase corresponding to a preS1 deletion reported to contribute to liver disease progression, can elicit an antiviral effect against human immunodeficiency virus (HIV)-1 by inhibiting HIV-1 integrase (IN) activity of infected cells. Mechanistic studies revealed that the anti-HIV-1 effects of Poly6 occurred via the inhibition of integration, which resulted from the inhibition of acetylation of HIV-1 IN possibly by downregulation of p300 histone acetyltransferase. Our data suggest the potential therapeutic use of a 6-mer HBV-derived peptide, Poly6, as an anti-HIV-1 agent to suppress HIV-1 infection via inhibiting integrase activity.
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Affiliation(s)
- Hong Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Cancer Research Institute and SNUMRC, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Republic of Korea
| | - So-Young Lee
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Cancer Research Institute and SNUMRC, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Republic of Korea
| | - Yu-Min Choi
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Cancer Research Institute and SNUMRC, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Republic of Korea
| | - Bum-Joon Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute, Cancer Research Institute and SNUMRC, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Republic of Korea.
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10
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Lv Y, Li J, Fang J, Jiao X, Yan L, Shan B. Systematic profiling of substrate binding response to multidrug-resistant mutations in HIV-1 protease: Implication for combating drug resistance. J Mol Graph Model 2017; 74:83-88. [PMID: 28371730 DOI: 10.1016/j.jmgm.2017.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 11/30/2022]
Abstract
Human immunodeficiency virus 1 (HIV-1) protease (PR) represents one of the primary targets for developing antiviral agents for the treatment of HIV-infected patients. However, a number of multidrug-resistant mutations in the enzyme have been observed over the past decades, largely limiting the application of PR inhibitors in antiviral therapy. A systematic investigation of the intermolecular interaction between the multidrug-resistant mutants of HIV-1 PR and its substrates would help to establish a complete profile of substrate response to PR mutations and to design new antiviral agents combating drug resistance. Here, we describe an integrative method to profile 6 clinical multidrug-resistant PR mutants against a panel of 16 substrate octapeptides that flank 12 distinct PR cleavage sites in viral precursor polyproteins. It is found that most multidrug-resistant mutations have only a modest or moderate effect on substrate peptide binding, although these mutations would cause a large free energy loss in PR inhibitor binding. Structural analysis reveals that the substrate peptides are loosely bound within PR active pocket to form a wide contact interface between them, and thus mutation of just single or few residues seems not to influence PR-substrate binding considerably. In addition, peptides derived from variable cleavage sites are generally more sensitive to the mutations as compared to those derived from conserved sites, supporting the co-evaluation mechanism of HIV-1 PR and its substrates under drug suppression. We also identify 12 functionally conserved key residues around the enzyme's active site, which play crucial role in substrate recognition. In vitro fluorescence anisotropy assays confirm that wild-type PR can bind substrate peptides ARVL/AEAM and NLAF/PQGE with a moderately high affinity (KD=2 and 16μM, respectively). In contrast, the key residue mutations N25D/D29N can completely eliminate (KD=n.d.) or largely reduce (KD=32 and 120μM, respectively) the binding capability of the two peptides, suggesting that these PR residues could be the potential target sites for developing resistance-free anti-HIV agents.
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Affiliation(s)
- Yonglei Lv
- Henan Red Cross Blood Center, Zhengzhou 450053, PR China
| | - Jianbing Li
- Henan Red Cross Blood Center, Zhengzhou 450053, PR China
| | - Jianhua Fang
- Henan Red Cross Blood Center, Zhengzhou 450053, PR China
| | - Xiufeng Jiao
- Henan Red Cross Blood Center, Zhengzhou 450053, PR China.
| | - Lumin Yan
- Henan Red Cross Blood Center, Zhengzhou 450053, PR China
| | - Baifeng Shan
- Shanxi Provincial Blood Center, Xi'an 710061, PR China
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11
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Adam GC, Meng J, Rizzo JM, Amoss A, Lusen JW, Patel A, Riley D, Hunt R, Zuck P, Johnson EN, Uebele VN, Hermes JD. Use of high-throughput mass spectrometry to reduce false positives in protease uHTS screens. ACTA ACUST UNITED AC 2014; 20:212-22. [PMID: 25336354 DOI: 10.1177/1087057114555832] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
As a label-free technology, mass spectrometry (MS) enables assays to be generated that monitor the conversion of substrates with native sequences to products without the requirement for substrate modifications or indirect detection methods. Although traditional liquid chromatography (LC)-MS methods are relatively slow for a high-throughput screening (HTS) paradigm, with cycle times typically ≥ 60 s per sample, the Agilent RapidFire High-Throughput Mass Spectrometry (HTMS) System, with a cycle time of 5-7 s per sample, enables rapid analysis of compound numbers compatible with HTS. By monitoring changes in mass directly, HTMS assays can be used as a triaging tool by eliminating large numbers of false positives resulting from fluorescent compound interference or from compounds interacting with hydrophobic fluorescent dyes appended to substrates. Herein, HTMS assays were developed for multiple protease programs, including cysteine, serine, and aspartyl proteases, and applied as a confirmatory assay. The confirmation rate for each protease assay averaged <30%, independent of the primary assay technology used (i.e., luminescent, fluorescent, and time-resolved fluorescent technologies). Importantly, >99% of compounds designed to inhibit the enzymes were confirmed by the corresponding HTMS assay. Hence, HTMS is an effective tool for removing detection-based false positives from ultrahigh-throughput screening, resulting in hit lists enriched in true actives for downstream dose response titrations and hit-to-lead efforts.
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Affiliation(s)
- Gregory C Adam
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Juncai Meng
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Joseph M Rizzo
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Adam Amoss
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Jeffrey W Lusen
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Amita Patel
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Daniel Riley
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Rachel Hunt
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Paul Zuck
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Eric N Johnson
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA Wuxi Apptech
| | - Victor N Uebele
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
| | - Jeffrey D Hermes
- Screening and Protein Sciences, Merck Research Labs, North Wales, PA, USA
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12
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Selvaraj C, Singh P, Singh SK. Molecular modeling studies and comparative analysis on structurally similar HTLV and HIV protease using HIV-PR inhibitors. J Recept Signal Transduct Res 2014; 34:361-71. [PMID: 24694004 DOI: 10.3109/10799893.2014.898659] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Retroviruses are most perilous viral family, which cause much damage to the Homo sapiens. HTLV-1 mechanism found to more similar with HIV-1 and both retroviruses are causative agents of severe and fatal diseases including adult T-cell leukemia (ATL) and the acquired immune deficiency syndrome (AIDS). Both viruses code for a protease (PR) that is essential for replication and therefore represents a key target for drugs interfering with viral infection. In this work, the comparative study of HIV-1 and HTLV-1 PR enzymes through sequence and structural analysis is reported along with approved drugs of HIV-PR. Conformation of each HIV PR drugs have been examined with different parameters of interactions and energy scorings parameters. MD simulations with respect to timescale event of 20 ns favors that, few HIV-PR inhibitors can be more active inside the HTLV-1 PR binding pocket. Overall results suggest that, some of HIV inhibitors like Tipranavir, Indinavir, Darunavir and Amprenavir are having good energy levels with HTLV-1. Due to absence of interactions with MET37, here we report that derivatives of these compounds can be much better inhibitors for targeting HTLV-1 proteolytic activity.
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Affiliation(s)
- Chandrabose Selvaraj
- Computer-Aided Drug Design and Molecular Modeling Lab, Department of Bioinformatics, Alagappa University , Karaikudi, Tamil Nadu , India and
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13
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Rabi SA, Laird GM, Durand CM, Laskey S, Shan L, Bailey JR, Chioma S, Moore RD, Siliciano RF. Multi-step inhibition explains HIV-1 protease inhibitor pharmacodynamics and resistance. J Clin Invest 2013; 123:3848-60. [PMID: 23979165 DOI: 10.1172/jci67399] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 05/30/2013] [Indexed: 11/17/2022] Open
Abstract
HIV-1 protease inhibitors (PIs) are among the most effective antiretroviral drugs. They are characterized by highly cooperative dose-response curves that are not explained by current pharmacodynamic theory. An unresolved problem affecting the clinical use of PIs is that patients who fail PI-containing regimens often have virus that lacks protease mutations, in apparent violation of fundamental evolutionary theory. Here, we show that these unresolved issues can be explained through analysis of the effects of PIs on distinct steps in the viral life cycle. We found that PIs do not affect virion release from infected cells but block entry, reverse transcription, and post-reverse transcription steps. The overall dose-response curves could be reconstructed by combining the curves for each step using the Bliss independence principle, showing that independent inhibition of multiple distinct steps in the life cycle generates the highly cooperative dose-response curves that make these drugs uniquely effective. Approximately half of the inhibitory potential of PIs is manifest at the entry step, likely reflecting interactions between the uncleaved Gag and the cytoplasmic tail (CT) of the Env protein. Sequence changes in the CT alone, which are ignored in current clinical tests for PI resistance, conferred PI resistance, providing an explanation for PI failure without resistance.
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Affiliation(s)
- S Alireza Rabi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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14
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Noel AF, Bilsel O, Kundu A, Wu Y, Zitzewitz JA, Matthews CR. The folding free-energy surface of HIV-1 protease: insights into the thermodynamic basis for resistance to inhibitors. J Mol Biol 2009; 387:1002-16. [PMID: 19150359 DOI: 10.1016/j.jmb.2008.12.061] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 12/20/2008] [Accepted: 12/22/2008] [Indexed: 11/28/2022]
Abstract
Spontaneous mutations at numerous sites distant from the active site of human immunodeficiency virus type 1 protease enable resistance to inhibitors while retaining enzymatic activity. As a benchmark for probing the effects of these mutations on the conformational adaptability of this dimeric beta-barrel protein, the folding free-energy surface of a pseudo-wild-type variant, HIV-PR(*), was determined by a combination of equilibrium and kinetic experiments on the urea-induced unfolding/refolding reactions. The equilibrium unfolding reaction was well described by a two-state model involving only the native dimeric form and the unfolded monomer. The global analysis of the kinetic folding mechanism reveals the presence of a fully folded monomeric intermediate that associates to form the native dimeric structure. Independent analysis of a stable monomeric version of the protease demonstrated that a small-amplitude fluorescence phase in refolding and unfolding, not included in the global analysis of the dimeric protein, reflects the presence of a transient intermediate in the monomer folding reaction. The partially folded and fully folded monomers are only marginally stable with respect to the unfolded state, and the dimerization reaction provides a modest driving force at micromolar concentrations of protein. The thermodynamic properties of this system are such that mutations can readily shift the equilibrium from the dimeric native state towards weakly folded states that have a lower affinity for inhibitors but that could be induced to bind to their target proteolytic sites. Presumably, subsequent secondary mutations increase the stability of the native dimeric state in these variants and, thereby, optimize the catalytic properties of the resistant human immunodeficiency virus type 1 protease.
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Affiliation(s)
- Amanda F Noel
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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15
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Heyda J, Pokorná J, Vrbka L, Vácha R, Jagoda-Cwiklik B, Konvalinka J, Jungwirth P, Vondrášek J. Ion specific effects of sodium and potassium on the catalytic activity of HIV-1 protease. Phys Chem Chem Phys 2009; 11:7599-604. [DOI: 10.1039/b905462f] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Anomalous adsorptive properties of HIV protease: Indication of two-dimensional crystallization? Colloids Surf B Biointerfaces 2008; 64:145-9. [DOI: 10.1016/j.colsurfb.2008.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Accepted: 01/15/2008] [Indexed: 11/23/2022]
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17
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Seibold SA, Cukier RI. A molecular dynamics study comparing a wild-type with a multiple drug resistant HIV protease: Differences in flap and aspartate 25 cavity dimensions. Proteins 2007; 69:551-65. [PMID: 17623840 DOI: 10.1002/prot.21535] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
HIV proteases can develop resistance to therapeutic drugs by mutating specific residues, but still maintain activity with their natural substrates. To gain insight into why mutations confer such resistance, long ( approximately 70 ns) Molecular Dynamics simulations in explicit solvent were performed on a multiple drug resistant (MDR) mutant (with Asn25 in the crystal structure mutated in silico back to the catalytically active Asp25) and a wild type (WT) protease. HIV proteases are homodimers, with characteristic flap tips whose conformations and dynamics are known to be important influences of ligand binding to the aspartates that form the catalytic center. The WT protease undergoes a transition between 25 and 35 ns that is absent in the MDR protease. The origin of this distinction is investigated using principal component analysis, and is related to differences in motion mainly in the flap region of each monomer. Trajectory analysis suggests that the WT transition arises from a concerted motion of the flap tip distances to their catalytic aspartate residues, and the distance between the two flap tips. These distances form a triangle that in the WT expands the active site from an initial (semi-open) form to an open form, in a correlated manner. In contrast, the MDR protease remains in a more closed configuration, with uncorrelated fluctuations in the distances defining the triangle. This contrasting behavior suggests that the MDR mutant achieves its resistance to drugs by making its active site less accessible to inhibitors. The migration of water to the active site aspartates is monitored. Water molecules move in and out of the active site and individual waters hydrogen bond to both aspartate carboxylate oxygens, with residence times in the ns time regime.
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Affiliation(s)
- Steve A Seibold
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, USA
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Garcia E, Hasenbank MS, Finlayson B, Yager P. High-throughput screening of enzyme inhibition using an inhibitor gradient generated in a microchannel. LAB ON A CHIP 2007; 7:249-55. [PMID: 17268628 DOI: 10.1039/b608789b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A new rapid microfluidic method for measuring enzyme inhibition is presented. The assay relies upon the creation of a uniform concentration of substrate and a microfluidically generated concentration gradient of inhibitor using a single microchannel and a single initial inhibitor concentration. The IC(50) values of two enzyme inhibitors were determined using the new technique and validated using a conventional microtiter plate assay. Using both experimental and computational simulation techniques, the assay was shown to be sensitive to inhibitor potency and the distribution of inhibitor in the system. The method has the potential to be more accurate than conventional methods because of the comparatively large amount of data that may be collected. Recommendations for use of the assay are provided, including its use for high-throughput screening in drug discovery and general use in measurement of enzyme inhibition.
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Affiliation(s)
- Elena Garcia
- Department of Bioengineering, University of Washington, Box 355061, Foege N530J, 1705 NE Pacific Street, Seattle, WA 98195-2255, USA
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19
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Abstract
Allostery involves coupling of conformational changes between two widely separated binding sites. The common view holds that allosteric proteins are symmetric oligomers, with each subunit existing in "at least" two conformational states with a different affinity for ligands. Recent observations such as the allosteric behavior of myoglobin, a classical example of a nonallosteric protein, call into question the existing allosteric dogma. Here we argue that all (nonfibrous) proteins are potentially allosteric. Allostery is a consequence of re-distributions of protein conformational ensembles. In a nonallosteric protein, the binding site shape may not show a concerted second-site change and enzyme kinetics may not reflect an allosteric transition. Nevertheless, appropriate ligands, point mutations, or external conditions may facilitate a population shift, leading a presumably nonallosteric protein to behave allosterically. In principle, practically any potential drug binding to the protein surface can alter the conformational redistribution. The question is its effectiveness in the redistribution of the ensemble, affecting the protein binding sites and its function. Here, we review experimental observations validating this view of protein allostery.
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Affiliation(s)
- K Gunasekaran
- Basic Research Program, SAIC-Frederick, Inc., Laboratory of Experimental and Computational Biology, National Cancer Institute-Frederick, Bldg 469, Rm 151, Frederick, Maryland 21702, USA
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Micheletti C, Carloni P, Maritan A. Accurate and efficient description of protein vibrational dynamics: Comparing molecular dynamics and Gaussian models. Proteins 2004; 55:635-45. [PMID: 15103627 DOI: 10.1002/prot.20049] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Current all-atom potential based molecular dynamics (MD) allows the identification of a protein's functional motions on a wide-range of timescales, up to few tens of nanoseconds. However, functional, large-scale motions of proteins may occur on a timescale currently not accessible by all-atom potential based MD. To avoid the massive computational effort required by this approach, several simplified schemes have been introduced. One of the most satisfactory is the Gaussian network approach based on the energy expansion in terms of the deviation of the protein backbone from its native configuration. Here, we consider an extension of this model that captures in a more realistic way the distribution of native interactions due to the introduction of effective side-chain centroids. Since their location is entirely determined by the protein backbone, the model is amenable to the same exact and computationally efficient treatment as previous simpler models. The ability of the model to describe the correlated motion of protein residues in thermodynamic equilibrium is established through a series of successful comparisons with an extensive (14 ns) MD simulation based on the AMBER potential of HIV-1 protease in complex with a peptide substrate. Thus, the model presented here emerges as a powerful tool to provide preliminary, fast yet accurate characterizations of protein near-native motion.
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21
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Shenderovich MD, Kagan RM, Heseltine PNR, Ramnarayan K. Structure-based phenotyping predicts HIV-1 protease inhibitor resistance. Protein Sci 2003; 12:1706-18. [PMID: 12876320 PMCID: PMC2323957 DOI: 10.1110/ps.0301103] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Mutations in HIV-1 drug targets lead to resistance and consequent therapeutic failure of antiretroviral drugs. Phenotypic resistance assays are time-consuming and costly, and genotypic rules-based interpretations may fail to predict the effects of multiple mutations. We have developed a computational procedure that rapidly evaluates changes in the binding energy of inhibitors to mutant HIV-1 PR variants. Models of WT complexes were produced from crystal structures. Mutant complexes were built by amino acid substitutions in the WT complexes with subsequent energy minimization of the ligand and PR binding site residues. Accuracy of the models was confirmed by comparison with available crystal structures and by prediction of known resistance-related mutations. PR variants from clinical isolates were modeled in complex with six FDA-approved PIs, and changes in the binding energy (DeltaE(bind)) of mutant versus WT complexes were correlated with the ratios of phenotypic 50% inhibitory concentration (IC(50)) values. The calculated DeltaE(bind) of five PIs showed significant correlations (R(2) = 0.7-0.8) with IC(50) ratios from the Virco Antivirogram assay, and the DeltaE(bind) of six PIs showed good correlation (R(2) = 0.76-0.85) with IC(50) ratios from the Virologic PhenoSense assay. DeltaE(bind) cutoffs corresponding to a four-fold increase in IC(50) were used to define the structure-based phenotype as susceptible, resistant, or equivocal. Blind predictions for 78 PR variants gave overall agreement of 92% (kappa = 0.756) and 86% (kappa = 0.666) with PhenoSense and Antivirogram phenotypes, respectively. The structural phenotyping predicted drug resistance of clinical HIV-1 PR variants with an accuracy approaching that of frequently used cell-based phenotypic assays.
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Affiliation(s)
- Mark D Shenderovich
- Cengent Therapeutics Inc., 10929 Technology Place, San Diego, CA 92127, USA.
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22
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Abstract
A comprehensive survey of the Pseudoviridae (Ty1/copia) retroelement family was conducted using the GenBank sequence database and completed genome sequences of several model organisms. Plant genomes were the most abundant sources of Pseudoviridae, with the Arabidopsis thaliana genome having 276 distinct elements. A reverse transcriptase amino acid sequence phylogeny indicated that the Pseudoviridae comprises highly divergent members. Coding sequences for a representative subset of elements were analyzed to identify conserved domains and differences that may underlie functional divergence. With the exception of some fungal elements (e.g., Ty1), most Pseudoviridae encode Gag and Pol on a single open reading frame. In addition to the nearly ubiquitous RNA-binding motif of nucleocapsid, three new conserved domains were identified in Gag. pol-encoded aspartic protease was similar to the retroviral enzyme and could be mapped onto the HIV-1 structure. Pol was highly conserved throughout the family. The greatest divergence among Pol sequences was seen in the C-terminus of integrase (IN). We defined a large motif (GKGY) after the IN catalytic domain that is unique to the Pseudoviridae. Additionally, the extreme C-terminus of IN is rich in simple sequence motifs. A distinct lineage of Pseudoviridae in plants have envlike genes. This lineage has undergone a large expansion of Gag characterized by an alpha-helix-rich domain containing coiled-coil motifs. In several elements, this domain is flanked on both sides by RNA-binding domains. We propose that this monophyletic lineage defines a new Pseudoviridae genus, herein referred to as the AGROVIRUS:
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Piana S, Carloni P, Rothlisberger U. Drug resistance in HIV-1 protease: Flexibility-assisted mechanism of compensatory mutations. Protein Sci 2002; 11:2393-402. [PMID: 12237461 PMCID: PMC2384161 DOI: 10.1110/ps.0206702] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The emergence of drug-resistant variants is a serious side effect associated with acquired immune deficiency syndrome therapies based on inhibition of human immunodeficiency virus type 1 protease (HIV-1 PR). In these variants, compensatory mutations, usually located far from the active site, are able to affect the enzymatic activity via molecular mechanisms that have been related to differences in the conformational flexibility, although the detailed mechanistic aspects have not been clarified so far. Here, we perform multinanosecond molecular dynamics simulations on L63P HIV-1 PR, corresponding to the wild type, and one of its most frequently occurring compensatory mutations, M46I, complexed with the substrate and an enzymatic intermediate. The quality of the calculations is established by comparison with the available nuclear magnetic resonance data. Our calculations indicate that the dynamical fluctuations of the mutated enzyme differ from those in the wild type. These differences in the dynamic properties of the adducts with the substrate and with the gem-diol intermediate might be directly related to variations in the enzymatic activity and therefore offer an explanation of the observed changes in catalytic rate between wild type and mutated enzyme. We anticipate that this "flexibility-assisted" mechanism might be effective in the vast majority of compensatory mutations, which do not change the electrostatic properties of the enzyme.
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Affiliation(s)
- Stefano Piana
- Laboratory of Inorganic Chemistry, ETH Hönggerberg-HCI, Zürich, Switzerland
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Micheletti C, Lattanzi G, Maritan A. Elastic properties of proteins: insight on the folding process and evolutionary selection of native structures. J Mol Biol 2002; 321:909-21. [PMID: 12206770 DOI: 10.1016/s0022-2836(02)00710-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We carry out a theoretical study of the vibrational and relaxation properties of naturally occurring proteins with the purpose of characterizing both the folding and equilibrium thermodynamics. By means of a suitable model, we provide a full characterization of the spectrum and eigenmodes of vibration at various temperatures by merely exploiting the knowledge of the protein native structure. It is shown that the rate at which perturbations decay at the folding transition correlates well with experimental folding rates. This validation is carried out on a list of about 30 two-state folders. Furthermore, the qualitative analysis of residues mean square displacements (shown to reproduce crystallographic data accurately) provides a reliable and statistically accurate method to identify crucial folding sites/contacts. This novel strategy is validated against clinical data for human immunodeficiency virus type 1 (HIV-1) protease. Finally, we compare the spectra and eigenmodes of vibration of natural proteins against randomly generated compact structures and regular random graphs. The comparison reveals a distinctive enhanced flexibility of natural structures accompanied by slow relaxation times at the folding temperature. The fact that these properties are connected intimately to the presence and assembly of secondary motifs hints at the special criteria adopted by evolution in the selection of viable folds.
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Affiliation(s)
- Cristian Micheletti
- International School for Advanced Studies (S.I.S.S.A.) and INFM, Via Beirut 2-4, 34014, Trieste, Italy.
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Piana S, Carloni P, Parrinello M. Role of conformational fluctuations in the enzymatic reaction of HIV-1 protease. J Mol Biol 2002; 319:567-83. [PMID: 12051929 DOI: 10.1016/s0022-2836(02)00301-7] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The emergence of compensatory drug-resistant mutations in HIV-1 protease challenges the common view of the reaction mechanism of this enzyme. Here, we address this issue by performing classical and ab initio molecular dynamics simulations (MD) on a complex between the enzyme and a peptide substrate. The classical MD calculation reveals large-scale protein motions involving the flaps and the cantilever. These motions modulate the conformational properties of the substrate at the cleavage site. The ab initio calculations show in turn that substrate motion modulates the activation free energy barrier of the enzymatic reaction dramatically. Thus, the catalytic power of the enzyme does not arise from the presence of a pre-organized active site but from the protein mechanical fluctuations. The implications of this finding for the emergence of drug-resistance are discussed.
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Affiliation(s)
- Stefano Piana
- Scuola Internazionale Superiore di Studi Avanzati and Istituto Nazionale di Fisica per la Materia, Via Beirut 2-4, 34014 Trieste, Italy
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26
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Abstract
The discovery and development of more than a dozen drugs in the past 15 years for the treatment of AIDS offer an excellent example of progress in the field of rational drug design. At this time, the principal targets are reverse transcriptase and protease, enzymes encoded by the human immunodeficiency virus. The introduction of protease inhibitors, in particular, has drastically decreased the mortality and morbidity associated with AIDS. This review presents the methods used to develop such drugs and discusses the remaining problems, such as the rapid emergence of drug resistance.
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Affiliation(s)
- Alexander Wlodawer
- Macromolecular Crystallography Laboratory, National Cancer Institute at Frederick, Frederick, Maryland 21702, USA.
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Yoshimura K, Kato R, Kavlick MF, Nguyen A, Maroun V, Maeda K, Hussain KA, Ghosh AK, Gulnik SV, Erickson JW, Mitsuya H. A potent human immunodeficiency virus type 1 protease inhibitor, UIC-94003 (TMC-126), and selection of a novel (A28S) mutation in the protease active site. J Virol 2002; 76:1349-58. [PMID: 11773409 PMCID: PMC135775 DOI: 10.1128/jvi.76.3.1349-1358.2002] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified UIC-94003, a nonpeptidic human immunodeficiency virus (HIV) protease inhibitor (PI), containing 3(R),3a(S),6a(R)-bis-tetrahydrofuranyl urethane (bis-THF) and a sulfonamide isostere, which is extremely potent against a wide spectrum of HIV (50% inhibitory concentration, 0.0003 to 0.0005 microM). UIC-94003 was also potent against multi-PI-resistant HIV-1 strains isolated from patients who had no response to any existing antiviral regimens after having received a variety of antiviral agents (50% inhibitory concentration, 0.0005 to 0.0055 microM). Upon selection of HIV-1 in the presence of UIC-94003, mutants carrying a novel active-site mutation, A28S, in the presence of L10F, M46I, I50V, A71V, and N88D appeared. Modeling analysis revealed that the close contact of UIC-94003 with the main chains of the protease active-site amino acids (Asp29 and Asp30) differed from that of other PIs and may be important for its potency and wide-spectrum activity against a variety of drug-resistant HIV-1 variants. Thus, introduction of inhibitor interactions with the main chains of key amino acids and seeking a unique inhibitor-enzyme contact profile should provide a framework for developing novel PIs for treating patients harboring multi-PI-resistant HIV-1.
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Affiliation(s)
- Kazuhisa Yoshimura
- Experimental Retrovirology Section, Medicine Branch, Division of Clinical Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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Chavan S, Kodoth S, Pahwa R, Pahwa S. The HIV protease inhibitor Indinavir inhibits cell-cycle progression in vitro in lymphocytes of HIV-infected and uninfected individuals. Blood 2001; 98:383-9. [PMID: 11435307 DOI: 10.1182/blood.v98.2.383] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Indinavir (IDV) is a potent and selective human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) widely used in antiretroviral therapy for suppression of HIV, but its effects on the immune system are relatively unknown. Recently, it has been reported that PIs inhibit lymphocyte apoptosis. In the present study we have investigated the effects of ex vivo addition of IDV on lymphocyte activation and apoptosis in cells from HIV-infected children (n = 18) and from healthy uninfected individuals (controls, n = 5) as well as in Jurkat and PM1 T-cell lines. Pretreatment of control peripheral blood mononuclear cell (PBMC) cultures with IDV resulted in a dose-dependent inhibition of lymphoproliferative responses to different activation stimuli. Additionally, this treatment led to cell-cycle arrest in G0/G1 phase in anti-CD3 monoclonal antibody-stimulated PBMC cultures in controls and in 15 of 18 HIV-infected children. Spontaneous- or activation-induced apoptosis of PBMCs from HIV-infected or uninfected individuals or of Fas-induced apoptosis in Jurkat and PM1 T cell lines were not inhibited by IDV. Moreover, IDV did not inhibit activation of caspases-1, -3, -4, -5, -9, and -8 in lysates of Jurkat T cells undergoing Fas-induced apoptosis. The findings indicate that IDV interferes with cell-cycle progression in primary cells but does not directly affect apoptosis. It is concluded that IDV may prolong cell survival indirectly by inhibiting their entry into cell cycle. In individuals on PI therapy, PI-mediated effects could potentially modulate immunologic responses independently of antiviral activity against HIV.
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Affiliation(s)
- S Chavan
- Division of Allergy/Immunology, Department of Pediatrics, North Shore University Hospital, New York University School of Medicine, Manhasset, NY 11030, USA
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29
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Cecconi F, Micheletti C, Carloni P, Maritan A. Molecular dynamics studies on HIV-1 protease: Drug resistance and folding pathways. Proteins 2001. [DOI: 10.1002/prot.1049] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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