1
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Rajendran M, Ferran MC, Mouli L, Babbitt GA, Lynch ML. Evolution of drug resistance drives destabilization of flap region dynamics in HIV-1 protease. BIOPHYSICAL REPORTS 2023; 3:100121. [PMID: 37662576 PMCID: PMC10469570 DOI: 10.1016/j.bpr.2023.100121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 08/07/2023] [Indexed: 09/05/2023]
Abstract
The HIV-1 protease is one of several common key targets of combination drug therapies for human immunodeficiency virus infection and acquired immunodeficiency syndrome. During the progression of the disease, some individual patients acquire drug resistance due to mutational hotspots on the viral proteins targeted by combination drug therapies. It has recently been discovered that drug-resistant mutations accumulate on the "flap region" of the HIV-1 protease, which is a critical dynamic region involved in nonspecific polypeptide binding during invasion and infection of the host cell. In this study, we utilize machine learning-assisted comparative molecular dynamics, conducted at single amino acid site resolution, to investigate the dynamic changes that occur during functional dimerization and drug binding of wild-type and common drug-resistant versions of the main protease. We also use a multiagent machine learning model to identify conserved dynamics of the HIV-1 main protease that are preserved across simian and feline protease orthologs. We find that a key conserved functional site in the flap region, a solvent-exposed isoleucine (Ile50) that controls flap dynamics is functionally targeted by drug resistance mutations, leading to amplified molecular dynamics affecting the functional ability of the flap region to hold the drugs. We conclude that better long-term patient outcomes may be achieved by designing drugs that target protease regions that are less dependent upon single sites with large functional binding effects.
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Affiliation(s)
- Madhusudan Rajendran
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York
| | - Maureen C. Ferran
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York
| | - Leora Mouli
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York
| | - Gregory A. Babbitt
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, Rochester, New York
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2
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Grasso D, Galderisi S, Santucci A, Bernini A. Pharmacological Chaperones and Protein Conformational Diseases: Approaches of Computational Structural Biology. Int J Mol Sci 2023; 24:ijms24065819. [PMID: 36982893 PMCID: PMC10054308 DOI: 10.3390/ijms24065819] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/09/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Whenever a protein fails to fold into its native structure, a profound detrimental effect is likely to occur, and a disease is often developed. Protein conformational disorders arise when proteins adopt abnormal conformations due to a pathological gene variant that turns into gain/loss of function or improper localization/degradation. Pharmacological chaperones are small molecules restoring the correct folding of a protein suitable for treating conformational diseases. Small molecules like these bind poorly folded proteins similarly to physiological chaperones, bridging non-covalent interactions (hydrogen bonds, electrostatic interactions, and van der Waals contacts) loosened or lost due to mutations. Pharmacological chaperone development involves, among other things, structural biology investigation of the target protein and its misfolding and refolding. Such research can take advantage of computational methods at many stages. Here, we present an up-to-date review of the computational structural biology tools and approaches regarding protein stability evaluation, binding pocket discovery and druggability, drug repurposing, and virtual ligand screening. The tools are presented as organized in an ideal workflow oriented at pharmacological chaperones' rational design, also with the treatment of rare diseases in mind.
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Affiliation(s)
- Daniela Grasso
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Silvia Galderisi
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Annalisa Santucci
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Andrea Bernini
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
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3
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Precursors of Viral Proteases as Distinct Drug Targets. Viruses 2021; 13:v13101981. [PMID: 34696411 PMCID: PMC8537868 DOI: 10.3390/v13101981] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/25/2021] [Accepted: 09/28/2021] [Indexed: 12/16/2022] Open
Abstract
Viral proteases are indispensable for successful virion maturation, thus making them a prominent drug target. Their enzyme activity is tightly spatiotemporally regulated by expression in the precursor form with little or no activity, followed by activation via autoprocessing. These cleavage events are frequently triggered upon transportation to a specific compartment inside the host cell. Typically, precursor oligomerization or the presence of a co-factor is needed for activation. A detailed understanding of these mechanisms will allow ligands with non-canonical mechanisms of action to be designed, which would specifically modulate the initial irreversible steps of viral protease autoactivation. Binding sites exclusive to the precursor, including binding sites beyond the protease domain, can be exploited. Both inhibition and up-regulation of the proteolytic activity of viral proteases can be detrimental for the virus. All these possibilities are discussed using examples of medically relevant viruses including herpesviruses, adenoviruses, retroviruses, picornaviruses, caliciviruses, togaviruses, flaviviruses, and coronaviruses.
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4
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Halder UC. Predicted antiviral drugs Darunavir, Amprenavir, Rimantadine and Saquinavir can potentially bind to neutralize SARS-CoV-2 conserved proteins. JOURNAL OF BIOLOGICAL RESEARCH (THESSALONIKE, GREECE) 2021; 28:18. [PMID: 34344455 PMCID: PMC8331326 DOI: 10.1186/s40709-021-00149-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/14/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND Novel Coronavirus disease 2019 or COVID-19 has become a threat to human society due to fast spreading and increasing mortality. It uses vertebrate hosts and presently deploys humans. Life cycle and pathogenicity of SARS-CoV-2 have already been deciphered and possible drug target trials are on the way. RESULTS The present study was aimed to analyze Non-Structural Proteins that include conserved enzymes of SARS-CoV-2 like papain-like protease, main protease, Replicase, RNA-dependent RNA polymerase, methyltransferase, helicase, exoribonuclease and endoribonucleaseas targets to all known drugs. A bioinformatic based web server Drug ReposeER predicted several drug binding motifs in these analyzed proteins. Results revealed that anti-viral drugs Darunavir,Amprenavir, Rimantadine and Saquinavir were the most potent to have 3D-drug binding motifs that were closely associated with the active sites of the SARS-CoV-2 enzymes . CONCLUSIONS Repurposing of the antiviral drugs Darunavir, Amprenavir, Rimantadine and Saquinavir to treat COVID-19 patients could be useful that can potentially prevent human mortality.
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Affiliation(s)
- Umesh C Halder
- Department of Zoology, Raniganj Girls' College, Searsole -Rajbari, Paschim Bardhaman, Raniganj, 713358, West Bengal, India.
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5
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Goyal B, Goyal D. Targeting the Dimerization of the Main Protease of Coronaviruses: A Potential Broad-Spectrum Therapeutic Strategy. ACS COMBINATORIAL SCIENCE 2020; 22:297-305. [PMID: 32402186 PMCID: PMC7252589 DOI: 10.1021/acscombsci.0c00058] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/13/2020] [Indexed: 12/12/2022]
Abstract
A new coronavirus (CoV) caused a pandemic named COVID-19, which has become a global health care emergency in the present time. The virus is referred to as SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) and has a genome similar (∼82%) to that of the previously known SARS-CoV (SARS coronavirus). An attractive therapeutic target for CoVs is the main protease (Mpro) or 3-chymotrypsin-like cysteine protease (3CLpro), as this enzyme plays a key role in polyprotein processing and is active in a dimeric form. Further, Mpro is highly conserved among various CoVs, and a mutation in Mpro is often lethal to the virus. Thus, drugs targeting the Mpro enzyme significantly reduce the risk of mutation-mediated drug resistance and display broad-spectrum antiviral activity. The combinatorial design of peptide-based inhibitors targeting the dimerization of SARS-CoV Mpro represents a potential therapeutic strategy. In this regard, we have compiled the literature reports highlighting the effect of mutations and N-terminal deletion of residues of SARS-CoV Mpro on its dimerization and, thus, catalytic activity. We believe that the present review will stimulate research in this less explored yet quite significant area. The effect of the COVID-19 epidemic and the possibility of future CoV outbreaks strongly emphasize the urgent need for the design and development of potent antiviral agents against CoV infections.
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Affiliation(s)
- Bhupesh Goyal
- School of Chemistry & Biochemistry,
Thapar Institute of Engineering & Technology,
Patiala-147004, Punjab, India
| | - Deepti Goyal
- Department of Chemistry, Faculty of Basic and Applied
Sciences, Sri Guru Granth Sahib World University, Fatehgarh
Sahib-140406, Punjab, India
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6
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Inhibition of HIV-1 Protease by Carpobrotus edulis (L.). EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:9648056. [PMID: 32595755 PMCID: PMC7298281 DOI: 10.1155/2020/9648056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/07/2020] [Accepted: 05/19/2020] [Indexed: 12/15/2022]
Abstract
Carpobrotus edulis (L.) is a plant commonly found in the Eastern Cape Province of South Africa and is used for the general treatment of infections relating to the human immunodeficiency virus (HIV). HIV-1 protease plays an important role during HIV replication and maturation to its infectious form, and therefore inhibition of the enzyme is one of the main focus areas in drug development. The inhibitory effect of a water extract of C. edulis leaves against HIV-1 protease activity was determined using the SensoLyte® 520 HIV-1 protease assay fluorimetric kit and employing a HiLyte Fluor™488/QXL™520 fluorescence resonance energy transfer (FRET) peptide. Cytotoxicity of the extract towards HeLa Chang cell lines was determined using an in vitro MTT assay, and the phytochemical profile of the extract was determined with FT-IR and LC-MS. HIV-1 protease activity was inhibited 83.06% (IC50 1.6 mg/ml) (p < 0.0001) by the pepstatin A inhibitor control. Treatment with all C. edulis extract concentrations (16, 1.6, 0.16, and 0.016 mg/ml) inhibited HIV-1 protease activity significantly (p < 0.0001) in a typical dose response manner. With regards to cytotoxicity, the negative controls containing untreated HeLa Chang cells exhibited high formazan formation rates in contrast with the positive controls, containing curcumin, which reduced formazan formation significantly (p < 0.001), exhibiting cytotoxicity towards the cells. There was no significant (p > 0.05) difference in the formazan formation rates between the negative controls and 1, 0.5, 0.125, 0.065, 0.031, and 0.015 mg/ml plant extract, confirming no toxicity of C. edulis extracts towards HeLa Chang cells. Major functional phytochemical compounds identified included alcohols, phenols, alkanes, amines, carboxylic acids, and esters. LC-ESI-TOF/MS analysis revealed the putative identities of main compounds present in the aqueous leaves extract, including some that contribute to its anti-HIV-1 protease action.
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7
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Stank A, Kokh DB, Horn M, Sizikova E, Neil R, Panecka J, Richter S, Wade RC. TRAPP webserver: predicting protein binding site flexibility and detecting transient binding pockets. Nucleic Acids Res 2019; 45:W325-W330. [PMID: 28431137 PMCID: PMC5570179 DOI: 10.1093/nar/gkx277] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/12/2017] [Indexed: 01/07/2023] Open
Abstract
The TRAnsient Pockets in Proteins (TRAPP) webserver provides an automated workflow that allows users to explore the dynamics of a protein binding site and to detect pockets or sub-pockets that may transiently open due to protein internal motion. These transient or cryptic sub-pockets may be of interest in the design and optimization of small molecular inhibitors for a protein target of interest. The TRAPP workflow consists of the following three modules: (i) TRAPP structure— generation of an ensemble of structures using one or more of four possible molecular simulation methods; (ii) TRAPP analysis—superposition and clustering of the binding site conformations either in an ensemble of structures generated in step (i) or in PDB structures or trajectories uploaded by the user; and (iii) TRAPP pocket—detection, analysis, and visualization of the binding pocket dynamics and characteristics, such as volume, solvent-exposed area or properties of surrounding residues. A standard sequence conservation score per residue or a differential score per residue, for comparing on- and off-targets, can be calculated and displayed on the binding pocket for an uploaded multiple sequence alignment file, and known protein sequence annotations can be displayed simultaneously. The TRAPP webserver is freely available at http://trapp.h-its.org.
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Affiliation(s)
- Antonia Stank
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany.,Heidelberg Graduate School of Mathematical and Computational Methods for the Sciences, Heidelberg University, Heidelberg, Baden-Württemberg 69120, Germany
| | - Daria B Kokh
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Max Horn
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Elena Sizikova
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Rebecca Neil
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Joanna Panecka
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Stefan Richter
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Baden-Württemberg 69118, Germany.,Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Baden-Württemberg 69120, Germany.,Center for Molecular Biology of the University of Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, Heidelberg, Baden-Württemberg 69120, Germany
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8
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Basciu A, Malloci G, Pietrucci F, Bonvin AMJJ, Vargiu AV. Holo-like and Druggable Protein Conformations from Enhanced Sampling of Binding Pocket Volume and Shape. J Chem Inf Model 2019; 59:1515-1528. [PMID: 30883122 DOI: 10.1021/acs.jcim.8b00730] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Understanding molecular recognition of small molecules by proteins in atomistic detail is key for drug design. Molecular docking is a widely used computational method to mimic ligand-protein association in silico. However, predicting conformational changes occurring in proteins upon ligand binding is still a major challenge. Ensemble docking approaches address this issue by considering a set of different conformations of the protein obtained either experimentally or from computer simulations, e.g., molecular dynamics. However, holo structures prone to host (the correct) ligands are generally poorly sampled by standard molecular dynamics simulations of the apo protein. In order to address this limitation, we introduce a computational approach based on metadynamics simulations called ensemble docking with enhanced sampling of pocket shape (EDES) that allows holo-like conformations of proteins to be generated by exploiting only their apo structures. This is achieved by defining a set of collective variables that effectively sample different shapes of the binding site, ultimately mimicking the steric effect due to the ligand. We assessed the method on three challenging proteins undergoing different extents of conformational changes upon ligand binding. In all cases our protocol generates a significant fraction of structures featuring a low RMSD from the experimental holo geometry. Moreover, ensemble docking calculations using those conformations yielded in all cases native-like poses among the top-ranked ones.
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Affiliation(s)
- Andrea Basciu
- Dipartimento di Fisica , Università di Cagliari, Cittadella Universitaria , I- 09042 Monserrato (CA) , Italy
| | - Giuliano Malloci
- Dipartimento di Fisica , Università di Cagliari, Cittadella Universitaria , I- 09042 Monserrato (CA) , Italy
| | - Fabio Pietrucci
- Sorbonne Université , Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC , F-75005 Paris , France
| | - Alexandre M J J Bonvin
- Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry , Utrecht University , Padualaan 8 , 3584 CH Utrecht , The Netherlands
| | - Attilio V Vargiu
- Dipartimento di Fisica , Università di Cagliari, Cittadella Universitaria , I- 09042 Monserrato (CA) , Italy.,Bijvoet Center for Biomolecular Research, Faculty of Science - Chemistry , Utrecht University , Padualaan 8 , 3584 CH Utrecht , The Netherlands
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9
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Tiberti M, Lechner BD, Fornili A. Binding Pockets in Proteins Induced by Mechanical Stress. J Chem Theory Comput 2019; 15:1-6. [PMID: 30525608 DOI: 10.1021/acs.jctc.8b00755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We report the first observation of a pocket that opens as a result of a mechanical force applied to an Ig-like domain from the cardiac muscle. This previously unseen mechanism of pocket formation is revealed by molecular dynamics simulations under force. Preliminary investigations show that this "mechano-pocket" is potentially druggable and could be found in other domains from the same fold family, suggesting the existence of a general mechanism of pocket formation under mechanical stress.
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Affiliation(s)
- Matteo Tiberti
- School of Biological and Chemical Sciences , Queen Mary University of London , London E1 4NS , United Kingdom
| | - Bob-Dan Lechner
- School of Biological and Chemical Sciences , Queen Mary University of London , London E1 4NS , United Kingdom
| | - Arianna Fornili
- School of Biological and Chemical Sciences , Queen Mary University of London , London E1 4NS , United Kingdom.,The Thomas Young Centre for Theory and Simulation of Materials , London , United Kingdom
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10
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Nayak C, Chandra I, Singh SK. An
in silico
pharmacological approach toward the discovery of potent inhibitors to combat drug resistance HIV‐1 protease variants. J Cell Biochem 2018; 120:9063-9081. [DOI: 10.1002/jcb.28181] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/08/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Chirasmita Nayak
- Computer Aided Drug Design and Molecular Modeling, Department of Bioinformatics Alagappa University Karaikudi India
| | - Ishwar Chandra
- Computer Aided Drug Design and Molecular Modeling, Department of Bioinformatics Alagappa University Karaikudi India
| | - Sanjeev Kumar Singh
- Computer Aided Drug Design and Molecular Modeling, Department of Bioinformatics Alagappa University Karaikudi India
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11
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Humpolíčková J, Weber J, Starková J, Mašínová E, Günterová J, Flaisigová I, Konvalinka J, Majerová T. Inhibition of the precursor and mature forms of HIV-1 protease as a tool for drug evaluation. Sci Rep 2018; 8:10438. [PMID: 29992979 PMCID: PMC6041310 DOI: 10.1038/s41598-018-28638-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/22/2018] [Indexed: 12/31/2022] Open
Abstract
HIV-1 protease (PR) is a homodimeric enzyme that is autocatalytically cleaved from the Gag-Pol precursor. Known PR inhibitors bind the mature enzyme several orders of magnitude more strongly than the PR precursor. Inhibition of PR at the precursor level, however, may stop the process at its rate-limiting step before the proteolytic cascade is initiated. Due to its structural heterogeneity, limited solubility and autoprocessing, the PR precursor is difficult to access by classical methods, and limited knowledge regarding precursor inhibition is available. Here, we describe a cell-based assay addressing precursor inhibition. We used a reporter molecule containing the transframe (TFP) and p6* peptides, PR, and N-terminal fragment of reverse transcriptase flanked by the fluorescent proteins mCherry and EGFP on its N- and C- termini, respectively. The level of FRET between EGFP and mCherry indicates the amount of unprocessed reporter, allowing specific monitoring of precursor inhibition. The inhibition can be quantified by flow cytometry. Additionally, two microscopy techniques confirmed that the reporter remains unprocessed within individual cells upon inhibition. We tested darunavir, atazanavir and nelfinavir and their combinations against wild-type PR. Shedding light on an inhibitor’s ability to act on non-mature forms of PR may aid novel strategies for next-generation drug design.
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Affiliation(s)
- Jana Humpolíčková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Jan Weber
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Jana Starková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Eva Mašínová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Jana Günterová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Iva Flaisigová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University in Prague, 12843, Prague, Czech Republic
| | - Taťána Majerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16610, Prague 6, Czech Republic.
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12
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Oleinikovas V, Saladino G, Cossins BP, Gervasio FL. Understanding Cryptic Pocket Formation in Protein Targets by Enhanced Sampling Simulations. J Am Chem Soc 2016; 138:14257-14263. [PMID: 27726386 DOI: 10.1021/jacs.6b05425] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cryptic pockets, that is, sites on protein targets that only become apparent when drugs bind, provide a promising alternative to classical binding sites for drug development. Here, we investigate the nature and dynamical properties of cryptic sites in four pharmacologically relevant targets, while comparing the efficacy of various simulation-based approaches in discovering them. We find that the studied cryptic sites do not correspond to local minima in the computed conformational free energy landscape of the unliganded proteins. They thus promptly close in all of the molecular dynamics simulations performed, irrespective of the force-field used. Temperature-based enhanced sampling approaches, such as Parallel Tempering, do not improve the situation, as the entropic term does not help in the opening of the sites. The use of fragment probes helps, as in long simulations occasionally it leads to the opening and binding to the cryptic sites. Our observed mechanism of cryptic site formation is suggestive of an interplay between two classical mechanisms: induced-fit and conformational selection. Employing this insight, we developed a novel Hamiltonian Replica Exchange-based method "SWISH" (Sampling Water Interfaces through Scaled Hamiltonians), which combined with probes resulted in a promising general approach for cryptic site discovery. We also addressed the issue of "false-positives" and propose a simple approach to distinguish them from druggable cryptic pockets. Our simulations, whose cumulative sampling time was more than 200 μs, help in clarifying the molecular mechanism of pocket formation, providing a solid basis for the choice of an efficient computational method.
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13
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Moreira C, Ramos MJ, Fernandes PA. Glutamine Synthetase Drugability beyond Its Active Site: Exploring Oligomerization Interfaces and Pockets. Molecules 2016; 21:E1028. [PMID: 27509490 PMCID: PMC6274088 DOI: 10.3390/molecules21081028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/01/2016] [Accepted: 08/04/2016] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Glutamine synthetase (GS) is a crucial enzyme to the nitrogen cycle with great commercial and pharmaceutical value. Current inhibitors target the active site, affecting GS activity indiscriminately in all organisms. As the active site is located at the interface between two monomers, the protein-protein interface (PPI) of GSs gains a new role, by providing new targets for enzyme inhibition. Exploring GSs PPI could allow for the development of inhibitors selective for specific organisms. Here we map the PPI of three GSs-human (hsGS), maize (zmGS) and Mycobacterium tuberculosis (mtGS)-and unravel new drugable pockets. METHODS The PPI binding free energy coming from key residues on three GSs from different organisms were mapped by computational alanine scan mutagenesis, applying a multiple dielectric constant MM-PBSA methodology. The most relevant residues for binding are referred as hot-spots. Drugable pockets on GS were detected with the Fpocket software. RESULTS AND CONCLUSIONS A total of 23, 19 and 30 hot-spots were identified on hsGS, zmGS and mtGS PPI. Even possessing differences in the hot-spots, hsGS and zmGS PPI are overall very similar. On the other hand, mtGS PPI differs greatly from hsGS and zmGS PPI. A novel drugable pocket was detected on the mtGS PPI. It seems particularly promising for the development of selective anti-tuberculosis drugs given its location on a PPI region that is highly populated with hot-spots and is completely different from the hsGS and zmGS PPIs. Drugs targeting this pockets should be inactive on eukaryotic GS II enzymes.
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Affiliation(s)
- Cátia Moreira
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
| | - Maria J Ramos
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
| | - Pedro A Fernandes
- UCIBIO, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
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14
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Midde NM, Patters BJ, Rao P, Cory TJ, Kumar S. Investigational protease inhibitors as antiretroviral therapies. Expert Opin Investig Drugs 2016; 25:1189-200. [PMID: 27415449 DOI: 10.1080/13543784.2016.1212837] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
INTRODUCTION Highly Active Antiretroviral Therapy (HAART) has tremendously improved the life expectancy of the HIV-infected population over the past three decades. Protease inhibitors have been one of the major classes of drugs in HAART regimens that are effective in treating HIV. However, the emergence of resistance and cross-resistance against protease inhibitors encourages researchers to develop new PIs with broad-spectrum activity, as well as novel means of enhancing the efficacy of existing PIs. AREAS COVERED In this article we discuss recent advances in HIV protease inhibitor (PI) development, focusing on both investigational and experimental agents. We also include a section on pharmacokinetic booster drugs for improved bioavailability of protease inhibitors. Further, we discuss novel drug delivery systems using a variety of nanocarriers for the delivery of PIs across the blood-brain barrier to treat the HIV in the brain. EXPERT OPINION We discuss our opinion on the promises and challenges on the development of novel investigational and experimental PIs that are less toxic and more effective in combating drug-resistance. Further, we discuss the future of novel nanocarriers that have been developed to deliver PIs to the brain cells. Although these are promising findings, many challenges need to be overcome prior to making them a viable option.
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Affiliation(s)
- Narasimha M Midde
- a Pharmaceutical Sciences , University of Tennessee Health Science Center , Memphis , TN , USA
| | - Benjamin J Patters
- a Pharmaceutical Sciences , University of Tennessee Health Science Center , Memphis , TN , USA
| | - Pss Rao
- b Pharmaceutical Science , College of Pharmacy, University of Findlay , Findlay , OH , USA
| | - Theodore J Cory
- c Clinical Pharmacy , University of Tennessee Health Science Center , Memphis , TN , USA
| | - Santosh Kumar
- a Pharmaceutical Sciences , University of Tennessee Health Science Center , Memphis , TN , USA
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