1
|
Isaguliants M, Zhitkevich A, Petkov S, Gorodnicheva T, Mezale D, Fridrihsone I, Kuzmenko Y, Kostyushev D, Kostyusheva A, Gordeychuk I, Bayurova E. Enzymatic activity of HIV-1 protease defines migration of tumor cells in vitro and enhances their metastatic activity in vivo. Biochimie 2024:S0300-9084(24)00195-0. [PMID: 39128490 DOI: 10.1016/j.biochi.2024.08.009] [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: 05/08/2024] [Revised: 07/09/2024] [Accepted: 08/08/2024] [Indexed: 08/13/2024]
Abstract
Overexpression of aspartic proteases, as cathepsin D, is an independent marker of poor prognosis in breast cancer, correlated with the incidence of clinical metastasis. We aimed to find if HIV-1 aspartic protease (PR) can play a similar role. Murine adenocarcinoma 4T1luc2 cells were transduced with lentivirus encoding inactivated drug-resistant PR, generating subclones PR20.1 and PR20.2. Subclones were assessed for production of reactive oxygen species (ROS), expression of epithelial-mesenchymal transition (EMT) factors, and in vitro migratory activity in the presence or absence of antioxidant N-acetyl cysteine and protease inhibitors. Tumorigenic activity was evaluated by implanting cells into BALB/c mice and following tumor growth by calipering and bioluminescence imaging in vivo, and metastases, by organ imaging ex vivo. Both subclones expressed PR mRNA, and PR20.2, also the protein detected by Western blotting. PR did not induce production of ROS, and had no direct effect on cell migration rate, however, treatment with inhibitors of drug-resistant PR suppressed the migratory activity of both subclones. Furthermore, expression of N-cadherin and Vimentin in PR20.2 cells and their migration were enhanced by antioxidant treatment. Sensitivity of in vitro migration to protease inhibitors and to antioxidant, known to restore PR activity, related the effects to the enzymatic activity of PR. In vivo, PR20.2 cells demonstrated higher tumorigenic and metastatic activity than PR20.1 or parental cells. Thus, HIV-1 protease expressed in breast cancer cells determines their migration in vitro and metastatic activity in vivo. This effect may aggravate clinical course of cancers in people living with HIV-1.
Collapse
Affiliation(s)
- M Isaguliants
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - A Zhitkevich
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819, Moscow, Russia.
| | - S Petkov
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - T Gorodnicheva
- Institute of Translational Medicine, Pirogov Russian National Research Medical University, 117997, Moscow, Russia.
| | - D Mezale
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - I Fridrihsone
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden.
| | - Y Kuzmenko
- Engelhardt Institute of Molecular Biology, Academy of Sciences of the Russian Federation, 119991, Moscow, Russia.
| | - D Kostyushev
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector-Borne Diseases, Sechenov University, 119991, Moscow, Russia.
| | - A Kostyusheva
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector-Borne Diseases, Sechenov University, 119991, Moscow, Russia.
| | - I Gordeychuk
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden; Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819, Moscow, Russia.
| | - E Bayurova
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177, Stockholm, Sweden; Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, 108819, Moscow, Russia.
| |
Collapse
|
2
|
Tran TT, Fanucci GE. Natural Polymorphisms D60E and I62V Stabilize a Closed Conformation in HIV-1 Protease in the Absence of an Inhibitor or Substrate. Viruses 2024; 16:236. [PMID: 38400012 PMCID: PMC10892587 DOI: 10.3390/v16020236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/18/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
HIV infection remains a global health issue plagued by drug resistance and virological failure. Natural polymorphisms (NPs) contained within several African and Brazilian protease (PR) variants have been shown to induce a conformational landscape of more closed conformations compared to the sequence of subtype B prevalent in North America and Western Europe. Here we demonstrate through experimental pulsed EPR distance measurements and molecular dynamic (MD) simulations that the two common NPs D60E and I62V found within subtypes F and H can induce a closed conformation when introduced into HIV-1PR subtype B. Specifically, D60E alters the conformation in subtype B through the formation of a salt bridge with residue K43 contained within the nexus between the flap and hinge region of the HIV-1 PR fold. On the other hand, I62V modulates the packing of the hydrophobic cluster of the cantilever and fulcrum, also resulting in a more closed conformation.
Collapse
Affiliation(s)
| | - Gail E. Fanucci
- Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
3
|
Ferreiro D, Khalil R, Sousa SF, Arenas M. Substitution Models of Protein Evolution with Selection on Enzymatic Activity. Mol Biol Evol 2024; 41:msae026. [PMID: 38314876 PMCID: PMC10873502 DOI: 10.1093/molbev/msae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/25/2024] [Accepted: 01/31/2024] [Indexed: 02/07/2024] Open
Abstract
Substitution models of evolution are necessary for diverse evolutionary analyses including phylogenetic tree and ancestral sequence reconstructions. At the protein level, empirical substitution models are traditionally used due to their simplicity, but they ignore the variability of substitution patterns among protein sites. Next, in order to improve the realism of the modeling of protein evolution, a series of structurally constrained substitution models were presented, but still they usually ignore constraints on the protein activity. Here, we present a substitution model of protein evolution with selection on both protein structure and enzymatic activity, and that can be applied to phylogenetics. In particular, the model considers the binding affinity of the enzyme-substrate complex as well as structural constraints that include the flexibility of structural flaps, hydrogen bonds, amino acids backbone radius of gyration, and solvent-accessible surface area that are quantified through molecular dynamics simulations. We applied the model to the HIV-1 protease and evaluated it by phylogenetic likelihood in comparison with the best-fitting empirical substitution model and a structurally constrained substitution model that ignores the enzymatic activity. We found that accounting for selection on the protein activity improves the fitting of the modeled functional regions with the real observations, especially in data with high molecular identity, which recommends considering constraints on the protein activity in the development of substitution models of evolution.
Collapse
Affiliation(s)
- David Ferreiro
- CINBIO, Universidade de Vigo, 36310 Vigo, Spain
- Department of Biochemistry, Genetics and Immunology, Universidade de Vigo, 36310 Vigo, Spain
| | - Ruqaiya Khalil
- CINBIO, Universidade de Vigo, 36310 Vigo, Spain
- Department of Biochemistry, Genetics and Immunology, Universidade de Vigo, 36310 Vigo, Spain
| | - Sergio F Sousa
- UCIBIO/REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal
| | - Miguel Arenas
- CINBIO, Universidade de Vigo, 36310 Vigo, Spain
- Department of Biochemistry, Genetics and Immunology, Universidade de Vigo, 36310 Vigo, Spain
| |
Collapse
|
4
|
Wang R, Zheng Q. Multiple Molecular Dynamics Simulations and Energy Analysis Unravel the Dynamic Properties and Binding Mechanism of Mutants HIV-1 Protease with DRV and CA-p2. Microbiol Spectr 2022; 10:e0074821. [PMID: 35319278 PMCID: PMC9045218 DOI: 10.1128/spectrum.00748-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 02/10/2022] [Indexed: 11/20/2022] Open
Abstract
PRS17, a variant of human immunodeficiency virus type I protease (HIV-1 PR), has 17 mutated residues showing high levels of multidrug resistance. To describe the effects of these mutated residues on the dynamic properties and the binding mechanism of PR with substrate and inhibitor, focused on six systems (two complexes of WT PR and PRS17 with inhibitor Darunavir (DRV), two complexes of WT PR and PRS17 with substrate analogue CA-p2, two unligand WT PR and PRS17), we performed multiple molecular dynamics (MD) simulations combined with MM-PBSA and solvated interaction energy (SIE) methods. For both the unligand PRs and ligand-PR complexes, the results from simulations revealed 17 mutated residues alter the flap-flap distance, the distance from flap regions to catalytic sites, and the curling degree of the flap tips. These mutated residues changed the flexibility of the flap region in PR, and thus affected its binding energy with DRV and CA-p2, resulting in differences in sensitivity. Hydrophobic cavity makes an important contribution to the binding of PR and ligands. And most noticeable of all, the binding of the guanidine group in CA-p2 and Arg8' of PRS17 is useful for increasing their binding ability. These results have important guidance for the further design of drugs against multidrug resistant PR. IMPORTANCE Developing effective anti-HIV inhibitors is the current requirement to cope with the emergence of the resistance of mutants. Compared with the experiments, MD simulations along with energy calculations help reduce the time and cost of designing new inhibitors. Based on our simulation results, we propose two factors that may help design effective inhibitors against HIV-1 PR: (i) importance of hydrophobic cavity, and (ii) introduction of polar groups similar to the guanidine group.
Collapse
Affiliation(s)
- Ruige Wang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, People's Republic of China
| | - Qingchuan Zheng
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun, People's Republic of China
| |
Collapse
|
5
|
Wang R, Zheng Q. Multiple Molecular Dynamics Simulations and Free-Energy Predictions Uncover the Susceptibility of Variants of HIV-1 Protease against Inhibitors Darunavir and KNI-1657. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14407-14418. [PMID: 34851643 DOI: 10.1021/acs.langmuir.1c02348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
HIV-1 protease (PR) is considered to be the main targets of anti-AIDS drug design because of its role in the proteolytic processing of viral polyproteins. However, the emergence of drug-resistant HIV has become a major problem in the therapy of HIV-1-infected patients. Focused on the complexes of wild type (WT) PR and two mutant PRs (V32I/L33F/I54M/V82I and V32I/L33F/I54M/I84 V) with inhibitors Darunavir (DRV) and KNI-1657 (KNI), respectively, we have conducted research on the conformational dynamics and the resistance mechanism caused by residue mutations through multiple molecular dynamics (MD) simulations combined with an energy (MM-PBSA and solvated interaction energy (SIE)) prediction. The results indicate that mutated residues of PR alter the distance between flap regions and catalytic sites, the volume of the inner catalytic site, and the curling degree of the flap tips, thereby affecting DRV and KNI inhibitor binding to PR. These mutated residues reduced the binding affinity of the two mutant PRs to DRV, resulting in drug resistance, whereas the two mutant PRs increase the binding affinity with KNI, indicating they enhance the sensitivity to KNI. Compared with the WT PR, the changes in van der Waals interaction and electrostatic interaction in the two variant PRs play a vital part in the binding of PR with DRV and KNI. These results may supply valuable guidance for the design of anti-AIDS drugs targeting PR.
Collapse
|
6
|
Ciftci D, Martens C, Ghani VG, Blanchard SC, Politis A, Huysmans GHM, Boudker O. Linking function to global and local dynamics in an elevator-type transporter. Proc Natl Acad Sci U S A 2021; 118:e2025520118. [PMID: 34873050 PMCID: PMC8670510 DOI: 10.1073/pnas.2025520118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2021] [Indexed: 11/24/2022] Open
Abstract
Transporters cycle through large structural changes to translocate molecules across biological membranes. The temporal relationships between these changes and function, and the molecular properties setting their rates, determine transport efficiency-yet remain mostly unknown. Using single-molecule fluorescence microscopy, we compare the timing of conformational transitions and substrate uptake in the elevator-type transporter GltPh We show that the elevator-like movements of the substrate-loaded transport domain across membranes and substrate release are kinetically heterogeneous, with rates varying by orders of magnitude between individual molecules. Mutations increasing the frequency of elevator transitions and reducing substrate affinity diminish transport rate heterogeneities and boost transport efficiency. Hydrogen deuterium exchange coupled to mass spectrometry reveals destabilization of secondary structure around the substrate-binding site, suggesting that increased local dynamics leads to faster rates of global conformational changes and confers gain-of-function properties that set transport rates.
Collapse
Affiliation(s)
- Didar Ciftci
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065
- Tri-Institutional Training Program in Chemical Biology, New York, NY 10065
| | - Chloe Martens
- Department of Chemistry, King's College London, London SE1 1DB, United Kingdom
| | - Vishnu G Ghani
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105
| | - Argyris Politis
- Department of Chemistry, King's College London, London SE1 1DB, United Kingdom
| | - Gerard H M Huysmans
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065;
| | - Olga Boudker
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY 10065;
- Tri-Institutional Training Program in Chemical Biology, New York, NY 10065
- Howard Hughes Medical Institute, Weill Cornell Medicine, New York, NY 10065
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Chen YS, Gleaton J, Yang Y, Dhayalan B, Phillips NB, Liu Y, Broadwater L, Jarosinski MA, Chatterjee D, Lawrence MC, Hattier T, Michael MD, Weiss MA. Insertion of a synthetic switch into insulin provides metabolite-dependent regulation of hormone-receptor activation. Proc Natl Acad Sci U S A 2021; 118:e2103518118. [PMID: 34290145 PMCID: PMC8325334 DOI: 10.1073/pnas.2103518118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Insulin-signaling requires conformational change: whereas the free hormone and its receptor each adopt autoinhibited conformations, their binding leads to structural reorganization. To test the functional coupling between insulin's "hinge opening" and receptor activation, we inserted an artificial ligand-dependent switch into the insulin molecule. Ligand-binding disrupts an internal tether designed to stabilize the hormone's native closed and inactive conformation, thereby enabling productive receptor engagement. This scheme exploited a diol sensor (meta-fluoro-phenylboronic acid at GlyA1) and internal diol (3,4-dihydroxybenzoate at LysB28). The sensor recognizes monosaccharides (fructose > glucose). Studies of insulin-signaling in human hepatoma-derived cells (HepG2) demonstrated fructose-dependent receptor autophosphorylation leading to appropriate downstream signaling events, including a specific kinase cascade and metabolic gene regulation (gluconeogenesis and lipogenesis). Addition of glucose (an isomeric ligand with negligible sensor affinity) did not activate the hormone. Similarly, metabolite-regulated signaling was not observed in control studies of 1) an unmodified insulin analog or 2) an analog containing a diol sensor without internal tethering. Although secondary structure (as probed by circular dichroism) was unaffected by ligand-binding, heteronuclear NMR studies revealed subtle local and nonlocal monosaccharide-dependent changes in structure. Insertion of a synthetic switch into insulin has thus demonstrated coupling between hinge-opening and allosteric holoreceptor signaling. In addition to this foundational finding, our results provide proof of principle for design of a mechanism-based metabolite-responsive insulin. In particular, replacement of the present fructose sensor by an analogous glucose sensor may enable translational development of a "smart" insulin analog to mitigate hypoglycemic risk in diabetes therapy.
Collapse
Affiliation(s)
- Yen-Shan Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | | | - Yanwu Yang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Balamurugan Dhayalan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Nelson B Phillips
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Yule Liu
- Thermalin Inc., Cleveland, OH 44106
| | | | - Mark A Jarosinski
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Deepak Chatterjee
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Michael C Lawrence
- Structural Biology Division, WEHI, Parkville, VIC 3052, Australia
- Department of Medical Biology, University of Melbourne, Royal Parade, Parkville, VIC 3050, Australia
| | | | | | - Michael A Weiss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202;
| |
Collapse
|
9
|
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.
Collapse
|
10
|
Leidner F, Yilmaz NK, Schiffer CA. Deciphering Complex Mechanisms of Resistance and Loss of Potency through Coupled Molecular Dynamics and Machine Learning. J Chem Theory Comput 2021; 17:2054-2064. [PMID: 33783217 PMCID: PMC8164521 DOI: 10.1021/acs.jctc.0c01244] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Drug resistance threatens many critical therapeutics through mutations in the drug target. The molecular mechanisms by which combinations of mutations, especially those remote from the active site, alter drug binding to confer resistance are poorly understood and thus difficult to counteract. A machine learning strategy was developed that coupled parallel molecular dynamics simulations with experimental potency to identify specific conserved mechanisms underlying resistance. Physical features were extracted from the simulations, analyzed, and integrated into one consistent and interpretable elastic network model. To rigorously test this strategy, HIV-1 protease variants with diverse mutations were used, with potencies ranging from picomolar to micromolar to the drug darunavir. Feature reduction resulted in a model with four specific features that predicts for both the training and test sets inhibitor binding free energy within 1 kcal/mol of the experimental value over this entire range of potency. These predictive features are physically interpretable, as they vary specifically with affinity and diagonally transverse across the protease homodimer. This physics-based strategy of parallel molecular dynamics and machine learning captures mechanisms by which complex combinations of mutations confer resistance and identify critical features that serve as bellwethers of affinity, which will be critical in future drug design.
Collapse
Affiliation(s)
- Florian Leidner
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Celia A. Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| |
Collapse
|
11
|
Eche S, Kumar A, Sonela N, Gordon ML. Acquired HIV-1 Protease Conformational Flexibility Associated with Lopinavir Failure May Shape the Outcome of Darunavir Therapy after Antiretroviral Therapy Switch. Biomolecules 2021; 11:489. [PMID: 33805099 PMCID: PMC8064090 DOI: 10.3390/biom11040489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/08/2021] [Accepted: 03/12/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the underlying molecular interaction during a therapy switch from lopinavir (LPV) to darunavir (DRV) is essential to achieve long-term virological suppression. We investigated the kinetic and structural characteristics of multidrug-resistant South African HIV-1 subtype C protease (HIV-1 PR) during therapy switch from LPV to DRV using enzyme activity and inhibition assay, fluorescence spectroscopy, and molecular dynamic simulation. The HIV-1 protease variants were from clinical isolates with a combination of drug resistance mutations; MUT-1 (M46I, I54V, V82A, and L10F), MUT-2 (M46I, I54V, L76V, V82A, L10F, and L33F), and MUT-3 (M46I, I54V, L76V, V82A, L90M, and F53L). Enzyme kinetics analysis shows an association between increased relative resistance to LPV and DRV with the progressive decrease in the mutant HIV-1 PR variants' catalytic efficiency. A direct relationship between high-level resistance to LPV and intermediate resistance to DRV with intrinsic changes in the three-dimensional structure of the mutant HIV-1 PR as a function of the multidrug-resistance mutation was observed. In silico analysis attributed these structural adjustments to the multidrug-resistance mutations affecting the LPV and DRV binding landscape. Though DRV showed superiority to LPV, as a lower concentration was needed to inhibit the HIV-1 PR variants, the inherent structural changes resulting from mutations selected during LPV therapy may dynamically shape the DRV treatment outcome after the therapy switch.
Collapse
Affiliation(s)
- Simeon Eche
- Discipline of Virology, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban 4001, South Africa;
| | - Ajit Kumar
- Discipline of Microbiology, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Durban 4000, South Africa;
| | - Nelson Sonela
- School of Medicine, Physical and Natural Sciences, University of Rome Tor Vegata, 1-00133 Rome, Italy;
- Chantal Biya International Reference Center for Research on the Management and Prevention of HIV/AIDS (CIRCB), Yaoundé P.O. Box 3077, Cameroon
| | - Michelle L. Gordon
- Discipline of Virology, School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban 4001, South Africa;
| |
Collapse
|
12
|
Matthew AN, Leidner F, Lockbaum GJ, Henes M, Zephyr J, Hou S, Desaboini NR, Timm J, Rusere LN, Ragland DA, Paulsen JL, Prachanronarong K, Soumana DI, Nalivaika EA, Yilmaz NK, Ali A, Schiffer CA. Drug Design Strategies to Avoid Resistance in Direct-Acting Antivirals and Beyond. Chem Rev 2021; 121:3238-3270. [PMID: 33410674 PMCID: PMC8126998 DOI: 10.1021/acs.chemrev.0c00648] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Drug resistance is prevalent across many diseases, rendering therapies ineffective with severe financial and health consequences. Rather than accepting resistance after the fact, proactive strategies need to be incorporated into the drug design and development process to minimize the impact of drug resistance. These strategies can be derived from our experience with viral disease targets where multiple generations of drugs had to be developed to combat resistance and avoid antiviral failure. Significant efforts including experimental and computational structural biology, medicinal chemistry, and machine learning have focused on understanding the mechanisms and structural basis of resistance against direct-acting antiviral (DAA) drugs. Integrated methods show promise for being predictive of resistance and potency. In this review, we give an overview of this research for human immunodeficiency virus type 1, hepatitis C virus, and influenza virus and the lessons learned from resistance mechanisms of DAAs. These lessons translate into rational strategies to avoid resistance in drug design, which can be generalized and applied beyond viral targets. While resistance may not be completely avoidable, rational drug design can and should incorporate strategies at the outset of drug development to decrease the prevalence of drug resistance.
Collapse
Affiliation(s)
- Ashley N. Matthew
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Virginia Commonwealth University
| | - Florian Leidner
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Gordon J. Lockbaum
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Mina Henes
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Jacqueto Zephyr
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Shurong Hou
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Nages Rao Desaboini
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Jennifer Timm
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Rutgers University
| | - Linah N. Rusere
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Raybow Pharmaceutical
| | - Debra A. Ragland
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- University of North Carolina, Chapel Hill
| | - Janet L. Paulsen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Schrodinger, Inc
| | - Kristina Prachanronarong
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Icahn School of Medicine at Mount Sinai
| | - Djade I. Soumana
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
- Cytiva
| | - Ellen A. Nalivaika
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Akbar Ali
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Baek I, Choi H, Yoon S, Na S. Effects of the Hydrophobicity of Key Residues on the Characteristics and Stability of Glucose Oxidase on a Graphene Surface. ACS Biomater Sci Eng 2020; 6:1899-1908. [PMID: 33455332 DOI: 10.1021/acsbiomaterials.9b01763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Glucose oxidase (GOx) is one of the most widely investigated enzymes in the field of bioelectrochemistry. It is mainly used for the detection of glucose in solutions and enzyme-based biofuel cells. On the basis of the combination of GOx with graphene, novel nanodevices exceeding conventional limits can be developed. To develop a hybrid enzyme-graphene nanodevice with a good performance, it is important that GOx is deposited well on the graphene surface while maintaining its structure and not impeding the oxidation activity of the GOx. In this study, we propose a method to improve the stability of GOx and secure its immobility on the graphene sheet and its glucose-binding affinity by single-point mutation of GOx using molecular dynamics simulations. We confirm that the structural stability, immobility, and substrate binding affinity of GOx can be modified by changing the hydrophobicity of a key residue. We demonstrate that biosensors or biofuel cells can be redesigned and their properties can be improved by using molecular dynamics simulation.
Collapse
Affiliation(s)
- Inchul Baek
- Department of Mechanical Engineering Korea University, Seoul 02481, Republic of Korea
| | - Hyunsung Choi
- Department of Mechanical Engineering Korea University, Seoul 02481, Republic of Korea
| | - Seongho Yoon
- College of Engineering Korea University, Seoul 02481, Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering Korea University, Seoul 02481, Republic of Korea
| |
Collapse
|
15
|
Inhibition of the activity of HIV-1 protease through antibody binding and mutations probed by molecular dynamics simulations. Sci Rep 2020; 10:5501. [PMID: 32218488 PMCID: PMC7098958 DOI: 10.1038/s41598-020-62423-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 03/12/2020] [Indexed: 01/31/2023] Open
Abstract
HIV-1 protease is an essential enzyme in the life cycle of the HIV-1 virus. The conformational dynamics of the flap region of the protease is critical for the ligand binding mechanism, as well as for the catalytic activity. The monoclonal antibody F11.2.32 raised against HIV-1 protease inhibits its activity on binding. We have studied the conformational dynamics of protease in its free, inhibitor ritonavir and antibody bound forms using molecular dynamics simulations. We find that upon Ab binding to the epitope region (residues 36-46) of protease, the overall flexibility of the protease is decreased including the flap region and the active site, which is similar to the decrease in flexibility observed by inhibitor binding to the protease. This suggests an allosteric mechanism to inhibit protease activity. Further, the protease mutants G40E and G40R are known to have decreased activity and were also subjected to MD simulations. We find that the loss of flexibility in the mutants is similar to that observed in the protease bound to the Ab/inhibitor. These insights highlight the role played by dynamics in the function of the protease and how control of flexibility through Ab binding and site specific mutations can inhibit protease activity.
Collapse
|
16
|
Wang RG, Zhang HX, Zheng QC. Revealing the binding and drug resistance mechanism of amprenavir, indinavir, ritonavir, and nelfinavir complexed with HIV-1 protease due to double mutations G48T/L89M by molecular dynamics simulations and free energy analyses. Phys Chem Chem Phys 2020; 22:4464-4480. [DOI: 10.1039/c9cp06657h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
MD simulations, MM-PBSA, and SIE analyses were used to investigate the drug resistance mechanisms of two mutations G48T and L89M in HIV-1 protease toward four inhibitors.
Collapse
Affiliation(s)
- Rui-Ge Wang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry
- Jilin University
- Changchun 130023
- P. R. China
| | - Hong-Xing Zhang
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry
- Jilin University
- Changchun 130023
- P. R. China
| | - Qing-Chuan Zheng
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry
- Jilin University
- Changchun 130023
- P. R. China
| |
Collapse
|
17
|
Molecular alteration in drug susceptibility against subtype B and C-SA HIV-1 proteases: MD study. Struct Chem 2019. [DOI: 10.1007/s11224-019-01305-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
18
|
Zhou H, Guterres H, Mattos C, Makowski L. Predicting X-ray solution scattering from flexible macromolecules. Protein Sci 2018; 27:2023-2036. [PMID: 30230663 PMCID: PMC6237699 DOI: 10.1002/pro.3508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/06/2018] [Accepted: 09/06/2018] [Indexed: 01/08/2023]
Abstract
Wide-angle X-ray solution scattering (WAXS) patterns contain substantial information about the structure and dynamics of a protein. Solution scattering from a rigid protein can be predicted from atomic coordinate sets to within experimental error. However, structural fluctuations of proteins in solution can lead to significant changes in the observed intensities. The magnitude and form of these changes contain information about the nature and spatial extent of structural fluctuations in the protein. Molecular dynamics (MD) simulations based on a crystal structure and selected force field generate models for protein internal motions, and here we demonstrate that they can be used to predict the impact of structural fluctuations on solution scattering data. In cases where the observed and calculated intensities correspond, we can conclude that the X-ray scattering provides direct experimental validation of the structural and MD results. In cases where calculated and observed intensities are at odds, the inconsistencies can be used to determine the origins of these discrepancies. They may be because of overestimates or underestimates of structural fluctuations in MD simulations, under-sampling of the structural ensemble in the simulations, errors in the structural model, or a mismatch between the experimental conditions and the parameters used in carrying out the MD simulation.
Collapse
Affiliation(s)
- Hao Zhou
- Department of Electrical and Computer EngineeringNortheastern UniversityBostonMassachusetts
| | - Hugo Guterres
- Department of Chemistry and Chemical BiologyNortheastern UniversityBostonMassachusetts
| | - Carla Mattos
- Department of Chemistry and Chemical BiologyNortheastern UniversityBostonMassachusetts
| | - Lee Makowski
- Department of BioengineeringNortheastern UniversityBostonMassachusetts
| |
Collapse
|
19
|
Conformational and dynamical basis for cross-reactivity observed between anti HIV-1 protease antibody with protease and an epitope peptide from it. Int J Biol Macromol 2018; 118:1696-1707. [PMID: 29990556 DOI: 10.1016/j.ijbiomac.2018.07.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 07/03/2018] [Accepted: 07/04/2018] [Indexed: 11/23/2022]
Abstract
F11.2.32 is a monoclonal antibody raised against HIV-1 protease and it inhibits protease activity. While the structure of the epitope peptide in complex with the antibody is known, how protease interacts with the antibody is not known. In this study, we model the conformational features of the free and bound epitope peptide and protease-antibody interactions. We find through our simulations, that the free epitope peptide P36-46 samples conformations akin to the bound conformation of the peptide in complex with the Ab, with a β-turn conformation sampled by the 38LPGR41 sequence highlighting the role of inherent conformational preferences of the peptide. Further, to determine the interactions present between the protease and antibody, we docked the protease in its conformation observed in the crystal structure, onto the antibody and simulated the dynamics of the complex in explicit water. We have identified the key residues involved in hydrogen-bond interactions and salt-bridges in Ag-Ab complex and examined the role of CDR flexibility in binding different conformations of the same epitope sequence in peptide and protein antigens. Thus, our results provide the basis for understanding the cross-reactivity observed between the antibody with protease and the epitope peptide from it.
Collapse
|
20
|
Maphumulo SI, Halder AK, Govender T, Maseko S, Maguire GEM, Honarparvar B, Kruger HG. Exploring the flap dynamics of the South African HIV subtype C protease in presence of FDA-approved inhibitors: MD study. Chem Biol Drug Des 2018; 92:1899-1913. [PMID: 30003668 DOI: 10.1111/cbdd.13364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 07/09/2018] [Indexed: 01/01/2023]
Abstract
HIV-1 protease (HIV PR) is considered as one of the most attractive targets for the treatment of HIV and the impact of flap dynamics of HIV PR on the binding affinities of protease inhibitors (PIs) is a crucial ongoing research field. Recently, our research group evaluated the binding affinities of different FDA approved PIs against the South African HIV-1 subtype C (C-SA) protease (PR). The CSA-HIV PR displayed weaker binding affinity for most of the clinical PIs compared to HIV-1 B subtype for West and Central Europe, the Americas. In the current work, the flap dynamics of four different systems of HIV-1 C-SA PR complexed to FDA approved second generation PIs and its impact on binding was explored over the molecular dynamic trajectories. It was observed that the interactions of the selected drugs with the binding site residues of the protease may not be the major contributor for affinity towards PIs. Various post-MD analyses were performed, also entropic contributions, solvation free energies and hydrophobic core formation interactions were studied to assess how the flap dynamics of C-SA PR which is affected by such factors. From these contributions, large van der Waals interactions and low solvation free energies were found to be major factors for the higher activity of ATV against C-SA HIV PR. Furthermore, a comparatively stable hydrophobic core may be responsible for higher stability of the PR flaps of the ATV complex. The outcome of this study provides significant guidance to how the flap dynamics of C-SA PR is affected by various factors as a result of the binding affinity of various protease inhibitors. It will also assist with the design of potent inhibitors against C-SA HIV PR that apart from binding in the active site of PR can interacts with the flaps to prevent opening of the flaps resulting in inactivation of the protease.
Collapse
Affiliation(s)
- Siyabonga I Maphumulo
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Amit K Halder
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sibusiso Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
21
|
Triki D, Billot T, Visseaux B, Descamps D, Flatters D, Camproux AC, Regad L. Exploration of the effect of sequence variations located inside the binding pocket of HIV-1 and HIV-2 proteases. Sci Rep 2018; 8:5789. [PMID: 29636521 PMCID: PMC5893546 DOI: 10.1038/s41598-018-24124-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
HIV-2 protease (PR2) is naturally resistant to most FDA (Food and Drug Administration)-approved HIV-1 protease inhibitors (PIs), a major antiretroviral class. In this study, we compared the PR1 and PR2 binding pockets extracted from structures complexed with 12 ligands. The comparison of PR1 and PR2 pocket properties showed that bound PR2 pockets were more hydrophobic with more oxygen atoms and fewer nitrogen atoms than PR1 pockets. The structural comparison of PR1 and PR2 pockets highlighted structural changes induced by their sequence variations and that were consistent with these property changes. Specifically, substitutions at residues 31, 46, and 82 induced structural changes in their main-chain atoms that could affect PI binding in PR2. In addition, the modelling of PR1 mutant structures containing V32I and L76M substitutions revealed a cooperative mechanism leading to structural deformation of flap-residue 45 that could modify PR2 flexibility. Our results suggest that substitutions in the PR1 and PR2 pockets can modify PI binding and flap flexibility, which could underlie PR2 resistance against PIs. These results provide new insights concerning the structural changes induced by PR1 and PR2 pocket variation changes, improving the understanding of the atomic mechanism of PR2 resistance to PIs.
Collapse
Affiliation(s)
- Dhoha Triki
- Molécules thérapeutiques in silico (MTi), INSERM UMR-, S973, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Telli Billot
- Molécules thérapeutiques in silico (MTi), INSERM UMR-, S973, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Benoit Visseaux
- IAME, UMR 1137, INSERM, Laboratoire de Virologie, Hôpital Bichât, AP-HP, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Diane Descamps
- IAME, UMR 1137, INSERM, Laboratoire de Virologie, Hôpital Bichât, AP-HP, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Delphine Flatters
- Molécules thérapeutiques in silico (MTi), INSERM UMR-, S973, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Anne-Claude Camproux
- Molécules thérapeutiques in silico (MTi), INSERM UMR-, S973, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Leslie Regad
- Molécules thérapeutiques in silico (MTi), INSERM UMR-, S973, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
| |
Collapse
|
22
|
Maseko SB, Padayachee E, Govender T, Sayed Y, Kruger G, Maguire GEM, Lin J. I36T↑T mutation in South African subtype C (C-SA) HIV-1 protease significantly alters protease-drug interactions. Biol Chem 2017; 398:1109-1117. [PMID: 28525359 DOI: 10.1515/hsz-2017-0107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/04/2017] [Indexed: 12/31/2022]
Abstract
The efficacy of HIV-1 protease (PR) inhibition therapies is often compromised by the emergence of mutations in the PR molecule that reduces the binding affinity of inhibitors while maintaining viable catalytic activity and affinity for natural substrates. In the present study, we used a recombinant HIV-1 C-SA PR and a recently reported variant for inhibition (Ki, IC50) and thermodynamic studies against nine clinically used inhibitors. This is the first time that binding free energies for C-SA PR and the mutant are reported. This variant PR harbours a mutation and insertion (I36T↑T) at position 36 of the C-SA HIV-1 PR, and did not show a significant difference in the catalytic effect of the HIV-1 PR. However, the nine clinically approved HIV PR drugs used in this study demonstrated weaker inhibition and lower binding affinities toward the variant when compared to the wild type HIV-1 PR. All the protease inhibitors (PIs), except Amprenavir and Ritonavir exhibited a significant decrease in binding affinity (p<0.0001). Darunavir and Nelfinavir exhibited the weakest binding affinity, 155- and 95-fold decreases respectively, toward the variant. Vitality values for the variant PR, against the seven selected PIs, confirm the impact of the mutation and insertion on the South African HIV-1 subtype C PR. This information has important clinical implications for thousands of patients in Sub-Saharan Africa.
Collapse
|
23
|
Flynn WF, Haldane A, Torbett BE, Levy RM. Inference of Epistatic Effects Leading to Entrenchment and Drug Resistance in HIV-1 Protease. Mol Biol Evol 2017; 34:1291-1306. [PMID: 28369521 PMCID: PMC5435099 DOI: 10.1093/molbev/msx095] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Understanding the complex mutation patterns that give rise to drug resistant viral strains provides a foundation for developing more effective treatment strategies for HIV/AIDS. Multiple sequence alignments of drug-experienced HIV-1 protease sequences contain networks of many pair correlations which can be used to build a (Potts) Hamiltonian model of these mutation patterns. Using this Hamiltonian model, we translate HIV-1 protease sequence covariation data into quantitative predictions for the probability of observing specific mutation patterns which are in agreement with the observed sequence statistics. We find that the statistical energies of the Potts model are correlated with the fitness of individual proteins containing therapy-associated mutations as estimated by in vitro measurements of protein stability and viral infectivity. We show that the penalty for acquiring primary resistance mutations depends on the epistatic interactions with the sequence background. Primary mutations which lead to drug resistance can become highly advantageous (or entrenched) by the complex mutation patterns which arise in response to drug therapy despite being destabilizing in the wildtype background. Anticipating epistatic effects is important for the design of future protease inhibitor therapies.
Collapse
Affiliation(s)
- William F. Flynn
- Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ
- Center for Biophysics and Computational Biology, Temple University, Philadelphia, PA
| | - Allan Haldane
- Center for Biophysics and Computational Biology, Temple University, Philadelphia, PA
- Department of Chemistry, Temple University, Philadelphia, PA
| | - Bruce E. Torbett
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA
| | - Ronald M. Levy
- Center for Biophysics and Computational Biology, Temple University, Philadelphia, PA
- Department of Chemistry, Temple University, Philadelphia, PA
| |
Collapse
|
24
|
Ung PMU, Ghanakota P, Graham SE, Lexa KW, Carlson HA. Identifying binding hot spots on protein surfaces by mixed-solvent molecular dynamics: HIV-1 protease as a test case. Biopolymers 2016; 105:21-34. [PMID: 26385317 DOI: 10.1002/bip.22742] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/14/2015] [Accepted: 09/14/2015] [Indexed: 12/16/2022]
Abstract
Mixed-solvent molecular dynamics (MixMD) simulations use full protein flexibility and competition between water and small organic probes to achieve accurate hot-spot mapping on protein surfaces. In this study, we improved MixMD using human immunodeficiency virus type-1 protease (HIVp) as the test case. We used three probe-water solutions (acetonitrile-water, isopropanol-water, and pyrimidine-water), first at 50% w/w concentration and later at 5% v/v. Paradoxically, better mapping was achieved by using fewer probes; 5% simulations gave a superior signal-to-noise ratio and far fewer spurious hot spots than 50% MixMD. Furthermore, very intense and well-defined probe occupancies were observed in the catalytic site and potential allosteric sites that have been confirmed experimentally. The Eye site, an allosteric site underneath the flap of HIVp, has been confirmed by the presence of a 5-nitroindole fragment in a crystal structure. MixMD also mapped two additional hot spots: the Exo site (between the Gly16-Gly17 and Cys67-Gly68 loops) and the Face site (between Glu21-Ala22 and Val84-Ile85 loops). The Exo site was observed to overlap with crystallographic additives such as acetate and dimethyl sulfoxide that are present in different crystal forms of the protein. Analysis of crystal structures of HIVp in different symmetry groups has shown that some surface sites are common interfaces for crystal contacts, which means that they are surfaces that are relatively easy to desolvate and complement with organic molecules. MixMD should identify these sites; in fact, their occupancy values help establish a solid cut-off where "druggable" sites are required to have higher occupancies than the crystal-packing faces.
Collapse
Affiliation(s)
- Peter M U Ung
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI, 48109-1065
| | - Phani Ghanakota
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI, 48109-1065
| | - Sarah E Graham
- Department of Biophysics, College of LSA, University of Michigan, 930 N. University St., Ann Arbor, MI, 48109-1055
| | - Katrina W Lexa
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI, 48109-1065
| | - Heather A Carlson
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI, 48109-1065.,Department of Biophysics, College of LSA, University of Michigan, 930 N. University St., Ann Arbor, MI, 48109-1055
| |
Collapse
|
25
|
Abstract
It is now common knowledge that enzymes are mobile entities relying on complex atomic-scale dynamics and coordinated conformational events for proper ligand recognition and catalysis. However, the exact role of protein dynamics in enzyme function remains either poorly understood or difficult to interpret. This mini-review intends to reconcile biophysical observations and biological significance by first describing a number of common experimental and computational methodologies employed to characterize atomic-scale residue motions on various timescales in enzymes, and second by illustrating how the knowledge of these motions can be used to describe the functional behavior of enzymes and even act upon it. Two biologically relevant examples will be highlighted, namely the HIV-1 protease and DNA polymerase β enzyme systems.
Collapse
|
26
|
Kurt Yilmaz N, Swanstrom R, Schiffer CA. Improving Viral Protease Inhibitors to Counter Drug Resistance. Trends Microbiol 2016; 24:547-557. [PMID: 27090931 DOI: 10.1016/j.tim.2016.03.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/18/2016] [Accepted: 03/30/2016] [Indexed: 12/13/2022]
Abstract
Drug resistance is a major problem in health care, undermining therapy outcomes and necessitating novel approaches to drug design. Extensive studies on resistance to viral protease inhibitors, particularly those of HIV-1 and hepatitis C virus (HCV) protease, revealed a plethora of information on the structural and molecular mechanisms underlying resistance. These insights led to several strategies to improve viral protease inhibitors to counter resistance, such as exploiting the essential biological function and leveraging evolutionary constraints. Incorporation of these strategies into structure-based drug design can minimize vulnerability to resistance, not only for viral proteases but for other quickly evolving drug targets as well, toward designing inhibitors one step ahead of evolution to counter resistance with more intelligent and rational design.
Collapse
Affiliation(s)
- Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Ronald Swanstrom
- Department of Biochemistry and Biophysics, and the UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
| |
Collapse
|
27
|
Anighoro A, Bajorath J. Three-Dimensional Similarity in Molecular Docking: Prioritizing Ligand Poses on the Basis of Experimental Binding Modes. J Chem Inf Model 2016; 56:580-7. [DOI: 10.1021/acs.jcim.5b00745] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Andrew Anighoro
- Department of Life Science
Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal
Chemistry, Rheinische Friedrich-Wilhelms-Universität, Dahlmannstrasse 2, D-53113 Bonn, Germany
| | - Jürgen Bajorath
- Department of Life Science
Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal
Chemistry, Rheinische Friedrich-Wilhelms-Universität, Dahlmannstrasse 2, D-53113 Bonn, Germany
| |
Collapse
|
28
|
Lockhat HA, Silva JRA, Alves CN, Govender T, Lameira J, Maguire GEM, Sayed Y, Kruger HG. Binding Free Energy Calculations of Nine FDA-approved Protease Inhibitors Against HIV-1 Subtype C I36T↑T Containing 100 Amino Acids Per Monomer. Chem Biol Drug Des 2016; 87:487-98. [PMID: 26613568 DOI: 10.1111/cbdd.12690] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 09/28/2015] [Accepted: 10/22/2015] [Indexed: 12/19/2022]
Abstract
In this work, have investigated the binding affinities of nine FDA-approved protease inhibitor drugs against a new HIV-1 subtype C mutated protease, I36T↑T. Without an X-ray crystal structure, homology modelling was used to generate a three-dimensional model of the protease. This and the inhibitor models were employed to generate the inhibitor/I36T↑T complexes, with the relative positions of the inhibitors being superimposed and aligned using the X-ray crystal structures of the inhibitors/HIV-1 subtype B complexes as a reference. Molecular dynamics simulations were carried out on the complexes to calculate the average binding free energies for each inhibitor using the molecular mechanics generalized Born surface area (MM-GBSA) method. When compared to the binding free energies of the HIV-1 subtype B and subtype C proteases (calculated previously by our group using the same method), it was clear that the I36T↑T proteases mutations and insertion had a significant negative effect on the binding energies of the non-pepditic inhibitors nelfinavir, darunavir and tipranavir. On the other hand, ritonavir, amprenavir and indinavir show improved calculated binding energies in comparison with the corresponding data for wild-type C-SA protease. The computational model used in this study can be used to investigate new mutations of the HIV protease and help in establishing effective HIV drug regimes and may also aid in future protease drug design.
Collapse
Affiliation(s)
- Husain A Lockhat
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - José R A Silva
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, Belém, PA, 66075-110, Brazil
| | - Cláudio N Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, Belém, PA, 66075-110, Brazil
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, Belém, PA, 66075-110, Brazil
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Yasien Sayed
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Wits, 2050, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| |
Collapse
|
29
|
Four Amino Acid Changes in HIV-2 Protease Confer Class-Wide Sensitivity to Protease Inhibitors. J Virol 2015; 90:1062-9. [PMID: 26559830 DOI: 10.1128/jvi.01772-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/02/2015] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Protease is essential for retroviral replication, and protease inhibitors (PI) are important for treating HIV infection. HIV-2 exhibits intrinsic resistance to most FDA-approved HIV-1 PI, retaining clinically useful susceptibility only to lopinavir, darunavir, and saquinavir. The mechanisms for this resistance are unclear; although HIV-1 and HIV-2 proteases share just 38 to 49% sequence identity, all critical structural features of proteases are conserved. Structural studies have implicated four amino acids in the ligand-binding pocket (positions 32, 47, 76, and 82). We constructed HIV-2ROD9 molecular clones encoding the corresponding wild-type HIV-1 amino acids (I32V, V47I, M76L, and I82V) either individually or together (clone PRΔ4) and compared the phenotypic sensitivities (50% effective concentration [EC50]) of mutant and wild-type viruses to nine FDA-approved PI. Single amino acid replacements I32V, V47I, and M76L increased the susceptibility of HIV-2 to multiple PI, but no single change conferred class-wide sensitivity. In contrast, clone PRΔ4 showed PI susceptibility equivalent to or greater than that of HIV-1 for all PI. We also compared crystallographic structures of wild-type HIV-1 and HIV-2 proteases complexed with amprenavir and darunavir to models of the PRΔ4 enzyme. These models suggest that the amprenavir sensitivity of PRΔ4 is attributable to stabilizing enzyme-inhibitor interactions in the P2 and P2' pockets of the protease dimer. Together, our results show that the combination of four amino acid changes in HIV-2 protease confer a pattern of PI susceptibility comparable to that of HIV-1, providing a structural rationale for intrinsic HIV-2 PI resistance and resolving long-standing questions regarding the determinants of differential PI susceptibility in HIV-1 and HIV-2. IMPORTANCE Proteases are essential for retroviral replication, and HIV-1 and HIV-2 proteases share a great deal of structural similarity. However, only three of nine FDA-approved HIV-1 protease inhibitors (PI) are active against HIV-2. The underlying reasons for intrinsic PI resistance in HIV-2 are not known. We examined the contributions of four amino acids in the ligand-binding pocket of the enzyme that differ between HIV-1 and HIV-2 by constructing HIV-2 clones encoding the corresponding HIV-1 amino acids and testing the PI susceptibilities of the resulting viruses. We found that the HIV-2 clone containing all four changes (PRΔ4) was as susceptible as HIV-1 to all nine PI. We also modeled the PRΔ4 enzyme structure and compared it to existing crystallographic structures of HIV-1 and HIV-2 proteases complexed with amprenavir and darunavir. Our findings demonstrate that four positions in the ligand-binding cleft of protease are the primary cause of HIV-2 PI resistance.
Collapse
|
30
|
Zhou H, Li S, Badger J, Nalivaika E, Cai Y, Foulkes-Murzycki J, Schiffer C, Makowski L. Modulation of HIV protease flexibility by the T80N mutation. Proteins 2015; 83:1929-39. [PMID: 25488402 PMCID: PMC4461556 DOI: 10.1002/prot.24737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/17/2014] [Accepted: 11/26/2014] [Indexed: 01/02/2023]
Abstract
The flexibility of HIV protease (HIVp) plays a critical role in enabling enzymatic activity and is required for substrate access to the active site. While the importance of flexibility in the flaps that cover the active site is well known, flexibility in other parts of the enzyme is also critical for function. One key region is a loop containing Thr 80, which forms the walls of the active site. Although not situated within the active site, amino acid Thr80 is absolutely conserved. The mutation T80N preserves the structure of the enzyme but catalytic activity is completely lost. To investigate the potential influence of the T80N mutation on HIVp flexibility, wide-angle X-ray scattering (WAXS) data was measured for a series of HIVp variants. Starting with a calculated WAXS pattern from a rigid atomic model, the modulations in the intensity distribution caused by structural fluctuations in the protein were predicted by simple analytic methods and compared with the experimental data. An analysis of T80N WAXS data shows that this variant is significantly more rigid than the WT across all length scales. The effects of this single point mutation extend throughout the protein, to alter the mobility of amino acids in the enzymatic core. These results support the contentions that significant protein flexibility extends throughout HIVp and is critical to catalytic function.
Collapse
Affiliation(s)
- Hao Zhou
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA
| | - Shangyang Li
- Department of Electrical and Computer Engineering, Northeastern University, Boston, MA
| | | | - Ellen Nalivaika
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Yufeng Cai
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Jennifer Foulkes-Murzycki
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Celia Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Lee Makowski
- Department of Bioengineering, Northeastern University, Boston, MA
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA
| |
Collapse
|
31
|
Analysis of the Zidovudine Resistance Mutations T215Y, M41L, and L210W in HIV-1 Reverse Transcriptase. Antimicrob Agents Chemother 2015; 59:7184-96. [PMID: 26324274 DOI: 10.1128/aac.05069-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 08/23/2015] [Indexed: 01/01/2023] Open
Abstract
Although anti-human immunodeficiency virus type 1 (HIV-1) therapies have become more sophisticated and more effective, drug resistance continues to be a major problem. Zidovudine (azidothymidine; AZT) was the first nucleoside reverse transcriptase (RT) inhibitor (NRTI) approved for the treatment of HIV-1 infections and is still being used, particularly in the developing world. This drug targets the conversion of single-stranded RNA to double-stranded DNA by HIV-1 RT. However, resistance to the drug quickly appeared both in viruses replicating in cells in culture and in patients undergoing AZT monotherapy. The primary resistance pathway selects for mutations of T215 that change the threonine to either a tyrosine or a phenylalanine (T215Y/F); this resistance pathway involves an ATP-dependent excision mechanism. The pseudo-sugar ring of AZT lacks a 3' OH; RT incorporates AZT monophosphate (AZTMP), which blocks the end of the viral DNA primer. AZT-resistant forms of HIV-1 RT use ATP in an excision reaction to unblock the 3' end of the primer strand, allowing its extension by RT. The T215Y AZT resistance mutation is often accompanied by two other mutations, M41L and L210W. In this study, the roles of these mutations, in combination with T215Y, were examined to determine whether they affect polymerization and excision by HIV-1 RT. The M41L mutation appears to help restore the DNA polymerization activity of RT containing the T215Y mutation and also enhances AZTMP excision. The L210W mutation plays a similar role, but it enhances excision by RTs that carry the T215Y mutation when ATP is present at a low concentration.
Collapse
|
32
|
Karshikoff A, Nilsson L, Ladenstein R. Rigidity versus flexibility: the dilemma of understanding protein thermal stability. FEBS J 2015; 282:3899-917. [PMID: 26074325 DOI: 10.1111/febs.13343] [Citation(s) in RCA: 176] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/17/2015] [Accepted: 06/09/2015] [Indexed: 01/19/2023]
Abstract
The role of fluctuations in protein thermostability has recently received considerable attention. In the current literature a dualistic picture can be found: thermostability seems to be associated with enhanced rigidity of the protein scaffold in parallel with the reduction of flexible parts of the structure. In contradiction to such arguments it has been shown by experimental studies and computer simulation that thermal tolerance of a protein is not necessarily correlated with the suppression of internal fluctuations and mobility. Both concepts, rigidity and flexibility, are derived from mechanical engineering and represent temporally insensitive features describing static properties, neglecting that relative motion at certain time scales is possible in structurally stable regions of a protein. This suggests that a strict separation of rigid and flexible parts of a protein molecule does not describe the reality correctly. In this work the concepts of mobility/flexibility versus rigidity will be critically reconsidered by taking into account molecular dynamics calculations of heat capacity and conformational entropy, salt bridge networks, electrostatic interactions in folded and unfolded states, and the emerging picture of protein thermostability in view of recently developed network theories. Last, but not least, the influence of high temperature on the active site and activity of enzymes will be considered.
Collapse
Affiliation(s)
- Andrey Karshikoff
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Lennart Nilsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Rudolf Ladenstein
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| |
Collapse
|
33
|
Effects of drug-resistant mutations on the dynamic properties of HIV-1 protease and inhibition by Amprenavir and Darunavir. Sci Rep 2015; 5:10517. [PMID: 26012849 PMCID: PMC4444956 DOI: 10.1038/srep10517] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/16/2015] [Indexed: 12/20/2022] Open
Abstract
Molecular dynamics simulations are performed to investigate the dynamic properties of wild-type HIV-1 protease and its two multi-drug-resistant variants (Flap + (L10I/G48V/I54V/V82A) and Act (V82T/I84V)) as well as their binding with APV and DRV inhibitors. The hydrophobic interactions between flap and 80 s (80’s) loop residues (mainly I50-I84’ and I50’-I84) play an important role in maintaining the closed conformation of HIV-1 protease. The double mutation in Act variant weakens the hydrophobic interactions, leading to the transition from closed to semi-open conformation of apo Act. APV or DRV binds with HIV-1 protease via both hydrophobic and hydrogen bonding interactions. The hydrophobic interactions from the inhibitor is aimed to the residues of I50 (I50’), I84 (I84’), and V82 (V82’) which create hydrophobic core clusters to further stabilize the closed conformation of flaps, and the hydrogen bonding interactions are mainly focused with the active site of HIV-1 protease. The combined change in the two kinds of protease-inhibitor interactions is correlated with the observed resistance mutations. The present study sheds light on the microscopic mechanism underlying the mutation effects on the dynamics of HIV-1 protease and the inhibition by APV and DRV, providing useful information to the design of more potent and effective HIV-1 protease inhibitors.
Collapse
|
34
|
Chetty S, Bhakat S, Martin AJM, Soliman MES. Multi-drug resistance profile of PR20 HIV-1 protease is attributed to distorted conformational and drug binding landscape: molecular dynamics insights. J Biomol Struct Dyn 2015; 34:135-51. [PMID: 25671669 DOI: 10.1080/07391102.2015.1018326] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The PR20 HIV-1 protease, a variant with 20 mutations, exhibits high levels of multi-drug resistance; however, to date, there has been no report detailing the impact of these 20 mutations on the conformational and drug binding landscape at a molecular level. In this report, we demonstrate the first account of a comprehensive study designed to elaborate on the impact of these mutations on the dynamic features as well as drug binding and resistance profile, using extensive molecular dynamics analyses. Comparative MD simulations for the wild-type and PR20 HIV proteases, starting from bound and unbound conformations in each case, were performed. Results showed that the apo conformation of the PR20 variant of the HIV protease displayed a tendency to remain in the open conformation for a longer period of time when compared to the wild type. This led to a phenomena in which the inhibitor seated at the active site of PR20 tends to diffuse away from the binding site leading to a significant change in inhibitor-protein association. Calculating the per-residue fluctuation (RMSF) and radius of gyration, further validated these findings. MM/GBSA showed that the occurrence of 20 mutations led to a drop in the calculated binding free energies (ΔGbind) by ~25.17 kcal/mol and ~5 kcal/mol for p2-NC, a natural peptide substrate, and darunavir, respectively, when compared to wild type. Furthermore, the residue interaction network showed a diminished inter-residue hydrogen bond network and changes in inter-residue connections as a result of these mutations. The increased conformational flexibility in PR20 as a result of loss of intra- and inter-molecular hydrogen bond interactions and other prominent binding forces led to a loss of protease grip on ligand. It is interesting to note that the difference in conformational flexibility between PR20 and WT conformations was much higher in the case of substrate-bound conformation as compared to DRV. Thus, developing analogues of DRV by retaining its key pharmacophore features will be the way forward in the search for novel protease inhibitors against multi-drug resistant strains.
Collapse
Affiliation(s)
- Sarentha Chetty
- a Molecular Modelling and Drug Design Research Group, School of Health Sciences , University of Kwazulu-Natal , Westville, Durban 4000 , South Africa
| | - Soumendranath Bhakat
- a Molecular Modelling and Drug Design Research Group, School of Health Sciences , University of Kwazulu-Natal , Westville, Durban 4000 , South Africa
| | - Alberto J M Martin
- b Computational Biology Lab, Fundación Ciencia & Vida , Santiago , Chile.,c Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso , Universidad de Valparaíso , Valparaíso , Chile
| | - Mahmoud E S Soliman
- a Molecular Modelling and Drug Design Research Group, School of Health Sciences , University of Kwazulu-Natal , Westville, Durban 4000 , South Africa
| |
Collapse
|
35
|
Özer N, Özen A, Schiffer CA, Haliloğlu T. Drug-resistant HIV-1 protease regains functional dynamics through cleavage site coevolution. Evol Appl 2015; 8:185-98. [PMID: 25685193 PMCID: PMC4319865 DOI: 10.1111/eva.12241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 12/08/2014] [Indexed: 12/20/2022] Open
Abstract
Drug resistance is caused by mutations that change the balance of recognition favoring substrate cleavage over inhibitor binding. Here, a structural dynamics perspective of the regained wild-type functioning in mutant HIV-1 proteases with coevolution of the natural substrates is provided. The collective dynamics of mutant structures of the protease bound to p1-p6 and NC-p1 substrates are assessed using the Anisotropic Network Model (ANM). The drug-induced protease mutations perturb the mechanistically crucial hinge axes that involve key sites for substrate binding and dimerization and mainly coordinate the intrinsic dynamics. Yet with substrate coevolution, while the wild-type dynamic behavior is restored in both p1-p6 ((LP) (1'F)p1-p6D30N/N88D) and NC-p1 ((AP) (2) (V)NC-p1V82A) bound proteases, the dynamic behavior of the NC-p1 bound protease variants (NC-p1V82A and (AP) (2) (V)NC-p1V82A) rather resemble those of the proteases bound to the other substrates, which is consistent with experimental studies. The orientational variations of residue fluctuations along the hinge axes in mutant structures justify the existence of coevolution in p1-p6 and NC-p1 substrates, that is, the dynamic behavior of hinge residues should contribute to the interdependent nature of substrate recognition. Overall, this study aids in the understanding of the structural dynamics basis of drug resistance and evolutionary optimization in the HIV-1 protease system.
Collapse
Affiliation(s)
- Nevra Özer
- Polymer Research Center and Chemical Engineering Department, Bogazici UniversityBebek, Istanbul, Turkey
| | - Ayşegül Özen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical SchoolWorcester, MA, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical SchoolWorcester, MA, USA
| | - Türkan Haliloğlu
- Polymer Research Center and Chemical Engineering Department, Bogazici UniversityBebek, Istanbul, Turkey
| |
Collapse
|
36
|
Goldfarb NE, Ohanessian M, Biswas S, McGee TD, Mahon BP, Ostrov DA, Garcia J, Tang Y, McKenna R, Roitberg A, Dunn BM. Defective hydrophobic sliding mechanism and active site expansion in HIV-1 protease drug resistant variant Gly48Thr/Leu89Met: mechanisms for the loss of saquinavir binding potency. Biochemistry 2015; 54:422-33. [PMID: 25513833 PMCID: PMC4303317 DOI: 10.1021/bi501088e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
![]()
HIV drug resistance continues to
emerge; consequently, there is
an urgent need to develop next generation antiretroviral therapeutics.1 Here we report on the structural and kinetic
effects of an HIV protease drug resistant variant with the double
mutations Gly48Thr and Leu89Met (PRG48T/L89M), without
the stabilizing mutations Gln7Lys, Leu33Ile, and Leu63Ile. Kinetic
analyses reveal that PRG48T/L89M and PRWT share
nearly identical Michaelis–Menten parameters; however, PRG48T/L89M exhibits weaker binding for IDV (41-fold), SQV (18-fold),
APV (15-fold), and NFV (9-fold) relative to PRWT. A 1.9
Å resolution crystal structure was solved for PRG48T/L89M bound with saquinavir (PRG48T/L89M-SQV) and compared
to the crystal structure of PRWT bound with saquinavir
(PRWT-SQV). PRG48T/L89M-SQV has
an enlarged active site resulting in the loss of a hydrogen bond in
the S3 subsite from Gly48 to P3 of SQV, as well as less favorable
hydrophobic packing interactions between P1 Phe of SQV and the S1
subsite. PRG48T/L89M-SQV assumes a more open conformation
relative to PRWT-SQV, as illustrated by the downward
displacement of the fulcrum and elbows and weaker interatomic flap
interactions. We also show that the Leu89Met mutation disrupts the
hydrophobic sliding mechanism by causing a redistribution of van der
Waals interactions in the hydrophobic core in PRG48T/L89M-SQV. Our mechanism for PRG48T/L89M-SQV drug resistance
proposes that a defective hydrophobic sliding mechanism results in
modified conformational dynamics of the protease. As a consequence,
the protease is unable to achieve a fully closed conformation that
results in an expanded active site and weaker inhibitor binding.
Collapse
Affiliation(s)
- Nathan E Goldfarb
- Department of Biochemistry and Molecular Biology, ‡Department of Chemistry, and §Departments of Pathology, Immunology, and Laboratory Medicine, University of Florida , Gainesville, Florida 32601-0245, United States
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Forli S, Olson AJ. Computational challenges of structure-based approaches applied to HIV. Curr Top Microbiol Immunol 2015; 389:31-51. [PMID: 25711462 DOI: 10.1007/82_2015_432] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Here, we review some of the opportunities and challenges that we face in computational modeling of HIV therapeutic targets and structural biology, both in terms of methodology development and structure-based drug design (SBDD). Computational methods have provided fundamental support to HIV research since the initial structural studies, helping to unravel details of HIV biology. Computational models have proved to be a powerful tool to analyze and understand the impact of mutations and to overcome their structural and functional influence in drug resistance. With the availability of structural data, in silico experiments have been instrumental in exploiting and improving interactions between drugs and viral targets, such as HIV protease, reverse transcriptase, and integrase. Issues such as viral target dynamics and mutational variability, as well as the role of water and estimates of binding free energy in characterizing ligand interactions, are areas of active computational research. Ever-increasing computational resources and theoretical and algorithmic advances have played a significant role in progress to date, and we envision a continually expanding role for computational methods in our understanding of HIV biology and SBDD in the future.
Collapse
Affiliation(s)
- Stefano Forli
- MGL, Department of Integrative Structural and Computational Biology and HIV Interaction and Viral Evolution Center, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA, 92037, USA
| | | |
Collapse
|
38
|
Naicker P, Stoychev S, Dirr HW, Sayed Y. Amide hydrogen exchange in HIV-1 subtype B and C proteases - insights into reduced drug susceptibility and dimer stability. FEBS J 2014; 281:5395-410. [DOI: 10.1111/febs.13084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 08/29/2014] [Accepted: 09/29/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Previn Naicker
- Protein Structure-Function Research Unit; School of Molecular and Cell Biology; University of the Witwatersrand; Johannesburg South Africa
| | - Stoyan Stoychev
- Council for Scientific and Industrial Research; Biosciences; Pretoria South Africa
| | - Heini W. Dirr
- 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
| |
Collapse
|
39
|
Structural basis and distal effects of Gag substrate coevolution in drug resistance to HIV-1 protease. Proc Natl Acad Sci U S A 2014; 111:15993-8. [PMID: 25355911 DOI: 10.1073/pnas.1414063111] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Drug resistance mutations in response to HIV-1 protease inhibitors are selected not only in the drug target but elsewhere in the viral genome, especially at the protease cleavage sites in the precursor protein Gag. To understand the molecular basis of this protease-substrate coevolution, we solved the crystal structures of drug resistant I50V/A71V HIV-1 protease with p1-p6 substrates bearing coevolved mutations. Analyses of the protease-substrate interactions reveal that compensatory coevolved mutations in the substrate do not restore interactions lost due to protease mutations, but instead establish other interactions that are not restricted to the site of mutation. Mutation of a substrate residue has distal effects on other residues' interactions as well, including through the induction of a conformational change in the protease. Additionally, molecular dynamics simulations suggest that restoration of active site dynamics is an additional constraint in the selection of coevolved mutations. Hence, protease-substrate coevolution permits mutational, structural, and dynamic changes via molecular mechanisms that involve distal effects contributing to drug resistance.
Collapse
|
40
|
Ragland DA, Nalivaika EA, Nalam MNL, Prachanronarong KL, Cao H, Bandaranayake RM, Cai Y, Kurt-Yilmaz N, Schiffer CA. Drug resistance conferred by mutations outside the active site through alterations in the dynamic and structural ensemble of HIV-1 protease. J Am Chem Soc 2014; 136:11956-63. [PMID: 25091085 PMCID: PMC4151706 DOI: 10.1021/ja504096m] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
HIV-1 protease inhibitors are part
of the highly active antiretroviral
therapy effectively used in the treatment of HIV infection and AIDS.
Darunavir (DRV) is the most potent of these inhibitors, soliciting
drug resistance only when a complex combination of mutations occur
both inside and outside the protease active site. With few exceptions,
the role of mutations outside the active site in conferring resistance
remains largely elusive. Through a series of DRV–protease complex
crystal structures, inhibition assays, and molecular dynamics simulations,
we find that single and double site mutations outside the active site
often associated with DRV resistance alter the structure and dynamic
ensemble of HIV-1 protease active site. These alterations correlate
with the observed inhibitor binding affinities for the mutants, and
suggest a network hypothesis on how the effect of
distal mutations are propagated to pivotal residues at the active
site and may contribute to conferring drug resistance.
Collapse
Affiliation(s)
- Debra A Ragland
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States
| | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Cai Y, Myint W, Paulsen JL, Schiffer CA, Ishima R, Kurt Yilmaz N. Drug Resistance Mutations Alter Dynamics of Inhibitor-Bound HIV-1 Protease. J Chem Theory Comput 2014; 10:3438-3448. [PMID: 25136270 PMCID: PMC4132871 DOI: 10.1021/ct4010454] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Indexed: 12/22/2022]
Abstract
![]()
Under the selective pressure of therapy,
HIV-1 protease mutants
resistant to inhibitors evolve to confer drug resistance. Such mutations
can impact both the dynamics and structures of the bound and unbound
forms of the enzyme. Flap+ is a multidrug-resistant variant of HIV-1
protease with a combination of primary and secondary resistance mutations
(L10I, G48V, I54V, V82A) and a strikingly altered thermodynamic profile
for darunavir (DRV) binding relative to the wild-type protease. We
elucidated the impact of these mutations on protein dynamics in the
DRV-bound state using molecular dynamics simulations and NMR relaxation
experiments. Both methods concur in that the conformational ensemble
and dynamics of protease are impacted by the drug resistance mutations
in Flap+ variant. Surprisingly this change in ensemble dynamics is
different from that observed in the unliganded form of the same variant
(Cai, Y. et al. J. Chem. Theory Comput.2012, 8, 3452–3462). Our comparative
analysis of both inhibitor-free and bound states presents a comprehensive
picture of the altered dynamics in drug-resistant mutant HIV-1 protease
and underlies the importance of incorporating dynamic analysis of
the whole system, including the unliganded state, into revealing drug
resistance mechanisms.
Collapse
Affiliation(s)
- Yufeng Cai
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States
| | - Wazo Myint
- Department of Structural Biology, School of Medicine, University of Pittsburgh Biomedical Science Tower 3 , 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Janet L Paulsen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States
| | - Rieko Ishima
- Department of Structural Biology, School of Medicine, University of Pittsburgh Biomedical Science Tower 3 , 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260, United States
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School , Worcester, Massachusetts 01605, United States
| |
Collapse
|
42
|
Kožíšek M, Lepšík M, Grantz Šašková K, Brynda J, Konvalinka J, Řezáčová P. Thermodynamic and structural analysis of HIV protease resistance to darunavir - analysis of heavily mutated patient-derived HIV-1 proteases. FEBS J 2014; 281:1834-47. [DOI: 10.1111/febs.12743] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Milan Kožíšek
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
| | - Martin Lepšík
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
| | - Klára Grantz Šašková
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
- Department of Biochemistry; Faculty of Science; Charles University; Prague Czech Republic
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
- Institute of Molecular Genetics; Academy of Sciences of the Czech Republic; Prague Czech Republic
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
- Department of Biochemistry; Faculty of Science; Charles University; Prague Czech Republic
| | - Pavlína Řezáčová
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; Gilead Sciences and IOCB Research Center; Prague Czech Republic
- Institute of Molecular Genetics; Academy of Sciences of the Czech Republic; Prague Czech Republic
| |
Collapse
|
43
|
Nakamoto M, Hoshino Y, Miura Y. Effect of Physical Properties of Nanogel Particles on the Kinetic Constants of Multipoint Protein Recognition Process. Biomacromolecules 2014; 15:541-7. [DOI: 10.1021/bm401536v] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Masahiko Nakamoto
- Department of Chemical Engineering, Kyushu University, 744
Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yu Hoshino
- Department of Chemical Engineering, Kyushu University, 744
Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yoshiko Miura
- Department of Chemical Engineering, Kyushu University, 744
Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| |
Collapse
|
44
|
Meher BR, Kumar MVS, Bandyopadhyay P. Interchain hydrophobic clustering promotes rigidity in HIV-1 protease flap dynamics: new insights from molecular dynamics. J Biomol Struct Dyn 2013; 32:899-915. [PMID: 23782135 DOI: 10.1080/07391102.2013.795873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The dynamics of HIV-1 protease (HIV-pr), a drug target for HIV infection, has been studied extensively by both computational and experimental methods. The flap dynamics of HIV-pr is considered to be more important for better ligand binding and enzymatic actions. Moreover, it has been demonstrated that the drug-induced mutations can change the flap dynamics of HIV-pr affecting the binding affinity of the ligands. Therefore, detailed understanding of flap dynamics is essential for designing better inhibitors. Previous computational investigations observed significant variation in the flap opening in nanosecond time scale indicating that the dynamics is highly sensitive to the simulation protocols. To understand the sensitivity of the flap dynamics on the force field and simulation protocol, molecular dynamics simulations of HIV-pr have been performed with two different AMBER force fields, ff99 and ff02. Two different trajectories (20 ns each) were obtained using the ff99 and ff02 force field. The results showed polarizable force field (ff02) make the flap tighter than the nonpolarizable force field (ff99). Some polar interactions and hydrogen bonds involving flap residues were found to be stronger with ff02 force field. The formation of interchain hydrophobic cluster (between flap tip of one chain and active site wall of another chain) was found to be dominant in the semi-open structures obtained from the simulations irrespective of the force field. It is proposed that an inhibitor, which will promote this interchain hydrophobic clustering, may make the flaps more rigid, and presumably the effect of mutation would be small on ligand binding.
Collapse
Affiliation(s)
- Biswa Ranjan Meher
- a Computational Biology Research Laboratory, Department of Biotechnology , Indian Institute of Technology , Guwahati , Assam , 781 039 , India
| | | | | |
Collapse
|
45
|
de Vera IMS, Smith AN, Dancel MCA, Huang X, Dunn BM, Fanucci GE. Elucidating a relationship between conformational sampling and drug resistance in HIV-1 protease. Biochemistry 2013; 52:3278-88. [PMID: 23566104 DOI: 10.1021/bi400109d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Enzyme targets in rapidly replicating systems, such as retroviruses, commonly respond to drug-selective pressure with mutations arising in the active site pocket that limit inhibitor effectiveness by introducing steric hindrance or by eliminating essential molecular interactions. However, these primary mutations are disposed to compromising pathogenic fitness. Emerging secondary mutations, which are often found outside of the binding cavity, may or can restore fitness while maintaining drug resistance. The accumulated drug pressure selected mutations could have an indirect effect in the development of resistance, such as altering protein flexibility or the dynamics of protein-ligand interactions. Here, we show that accumulation of mutations in a drug-resistant HIV-1 protease (HIV-1 PR) variant, D30N/M36I/A71V, changes the fractional occupancy of the equilibrium conformational sampling ensemble. Correlations are made among populations of the conformational states, namely, closed-like, semiopen, and open-like, with inhibition constants, as well as kinetic parameters. Mutations that stabilize a closed-like conformation correlate with enzymes of lowered activity and with higher affinity for inhibitors, which is corroborated by a further increase in the fractional occupancy of the closed state upon addition of inhibitor or substrate-mimic. Cross-resistance is found to correlate with combinations of mutations that increase the population of the open-like conformations at the expense of the closed-like state while retaining native-like occupancy of the semiopen population. These correlations suggest that at least three states are required in the conformational sampling model to establish the emergence of drug resistance in HIV-1 PR. More importantly, these results shed light on a possible mechanism whereby mutations combine to impart drug resistance while maintaining catalytic activity.
Collapse
Affiliation(s)
- Ian Mitchelle S de Vera
- Department of Chemistry, P.O. Box 117200, University of Florida , Gainesville, Florida 32611-7200, United States
| | | | | | | | | | | |
Collapse
|
46
|
Pollack JD, Gerard D, Pearl DK. Uniquely localized intra-molecular amino acid concentrations at the glycolytic enzyme catalytic/active centers of Archaea, Bacteria and Eukaryota are associated with their proposed temporal appearances on earth. ORIGINS LIFE EVOL B 2013; 43:161-87. [PMID: 23715690 DOI: 10.1007/s11084-013-9331-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 04/04/2013] [Indexed: 11/27/2022]
Abstract
The distributions of amino acids at most-conserved sites nearest catalytic/active centers (C/AC) in 4,645 sequences of ten enzymes of the glycolytic Embden-Meyerhof-Parnas pathway in Archaea, Bacteria and Eukaryota are similar to the proposed temporal order of their appearance on Earth. Glycine, isoleucine, leucine, valine, glutamic acid and possibly lysine often described as prebiotic, i.e., existing or occurring before the emergence of life, were localized in positional and conservational defined aggregations in all enzymes of all Domains. The distributions of all 20 biologic amino acids in most-conserved sites nearest their C/ACs were quite different either from distributions in sites less-conserved and further from their C/ACs or from all amino acids regardless of their position or conservation. The major concentrations of glycine, e.g., perhaps the earliest prebiotic amino acid, occupies ≈ 16 % of all the most-conserved sites within a volume of ≈ 7-8 Å radius from their C/ACs and decreases linearly towards the molecule's peripheries. Spatially localized major concentrations of isoleucine, leucine and valine are in the mid-conserved and mid-distant sites from their C/ACs in protein interiors. Lysine and glutamic acid comprise ≈ 25-30 % of all amino acids within an irregular volume bounded by ≈ 24-28 Å radii from their C/ACs at the most-distant least-conserved sites. The unreported characteristics of these amino acids: their spatially and conservationally identified concentrations in Archaea, Bacteria and Eukaryota, suggest some common structural organization of glycolytic enzymes that may be relevant to their evolution and that of other proteins. We discuss our data in relation to enzyme evolution, their reported prebiotic putative temporal appearances on Earth, abundances, biological "cost", neighbor-sequence preferences or "ordering" and some thermodynamic parameters.
Collapse
Affiliation(s)
- J Dennis Pollack
- Department of Molecular Virology, Immunology and Medical Genetics, The College of Medicine, The Ohio State University, Columbus, OH 43210, USA.
| | | | | |
Collapse
|
47
|
Tiefenbrunn T, Forli S, Baksh MM, Chang MW, Happer M, Lin YC, Perryman AL, Rhee JK, Torbett BE, Olson AJ, Elder JH, Finn MG, Stout CD. Small molecule regulation of protein conformation by binding in the Flap of HIV protease. ACS Chem Biol 2013; 8:1223-31. [PMID: 23540839 DOI: 10.1021/cb300611p] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The fragment indole-6-carboxylic acid (1F1), previously identified as a flap site binder in a fragment-based screen against HIV protease (PR), has been cocrystallized with pepstatin-inhibited PR and with apo-PR. Another fragment, 3-indolepropionic acid (1F1-N), predicted by AutoDock calculations and confirmed in a novel inhibition of nucleation crystallization assay, exploits the same interactions in the flap site in two crystal structures. Both 1F1 and 1F1-N bind to the closed form of apo-PR and to pepstatin:PR. In solution, 1F1 and 1F1-N raise the Tm of apo-PR by 3.5-5 °C as assayed by differential scanning fluorimetry (DSF) and show equivalent low-micromolar binding constants to both apo-PR and pepstatin:PR, assayed by backscattering interferometry (BSI). The observed signal intensities in BSI are greater for each fragment upon binding to apo-PR than to pepstatin-bound PR, consistent with greater conformational change in the former binding event. Together, these data indicate that fragment binding in the flap site favors a closed conformation of HIV PR.
Collapse
Affiliation(s)
- Theresa Tiefenbrunn
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Stefano Forli
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Michael M. Baksh
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Max W. Chang
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Meaghan Happer
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Ying-Chuan Lin
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Alexander L. Perryman
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Jin-Kyu Rhee
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Bruce E. Torbett
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Arthur J. Olson
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - John H. Elder
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - M. G. Finn
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - C. David Stout
- Deparatment
of Integrative Structural and Computational Biology, ‡Department of Chemistry, §Department of Molecular
and Experimental Medicine, ∥Department of Immunology and Microbial Science, The Scripps Research Institute, 10550
N. Torrey Pines Rd., La Jolla, California 92037, United States
| |
Collapse
|
48
|
Doyle CM, Rumfeldt JA, Broom HR, Broom A, Stathopulos PB, Vassall KA, Almey JJ, Meiering EM. Energetics of oligomeric protein folding and association. Arch Biochem Biophys 2012; 531:44-64. [PMID: 23246784 DOI: 10.1016/j.abb.2012.12.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/29/2012] [Accepted: 12/05/2012] [Indexed: 12/11/2022]
Abstract
In nature, proteins most often exist as complexes, with many of these consisting of identical subunits. Understanding of the energetics governing the folding and misfolding of such homooligomeric proteins is central to understanding their function and misfunction, in disease or biotechnology. Much progress has been made in defining the mechanisms and thermodynamics of homooligomeric protein folding. In this review, we outline models as well as calorimetric and spectroscopic methods for characterizing oligomer folding, and describe extensive results obtained for diverse proteins, ranging from dimers to octamers and higher order aggregates. To our knowledge, this area has not been reviewed comprehensively in years, and the collective progress is impressive. The results provide evolutionary insights into the development of subunit interfaces, mechanisms of oligomer folding, and contributions of oligomerization to protein stability, function and regulation. Thermodynamic analyses have also proven valuable for understanding protein misfolding and aggregation mechanisms, suggesting new therapeutic avenues. Successful recent designs of novel, functional proteins demonstrate increased understanding of oligomer folding. Further rigorous analyses using multiple experimental and computational approaches are still required, however, to achieve consistent and accurate prediction of oligomer folding energetics. Modeling the energetics remains challenging but is a promising avenue for future advances.
Collapse
Affiliation(s)
- Colleen M Doyle
- Guelph-Waterloo Centre for Graduate Studies in Chemistry and Biochemistry, and Department of Chemistry, University of Waterloo, 200 University Ave. West, Waterloo, ON, Canada
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Ahmed SM, Kruger HG, Govender T, Maguire GEM, Sayed Y, Ibrahim MAA, Naicker P, Soliman MES. Comparison of the Molecular Dynamics and Calculated Binding Free Energies for Nine FDA-Approved HIV-1 PR Drugs Against Subtype B and C-SA HIV PR. Chem Biol Drug Des 2012; 81:208-18. [DOI: 10.1111/cbdd.12063] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
50
|
Cai Y, Yilmaz NK, Myint W, Ishima R, Schiffer CA. Differential Flap Dynamics in Wild-type and a Drug Resistant Variant of HIV-1 Protease Revealed by Molecular Dynamics and NMR Relaxation. J Chem Theory Comput 2012; 8:3452-3462. [PMID: 23144597 PMCID: PMC3491577 DOI: 10.1021/ct300076y] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the rapidly evolving disease of HIV drug resistance readily emerges, nullifying the effectiveness of therapy. Drug resistance has been extensively studied in HIV-1 protease where resistance occurs when the balance between enzyme inhibition and substrate recognition and turn-over is perturbed to favor catalytic activity. Mutations which confer drug resistance can impact the dynamics and structure of both the bound and unbound forms of the enzyme. Flap+ is a multi-drug-resistant variant of HIV-1 protease with a combination of mutations at the edge of the active site, within the active site, and in the flaps (L10I, G48V, I54V, V82A). The impact of these mutations on the dynamics in the unliganded form in comparison with the wild-type protease was elucidated with Molecular Dynamic simulations and NMR relaxation experiments. The comparative analyses from both methods concur in showing that the enzyme's dynamics are impacted by the drug resistance mutations in Flap+ protease. These alterations in the enzyme dynamics, particularly within the flaps, likely modulate the balance between substrate turn-over and drug binding, thereby conferring drug resistance.
Collapse
Affiliation(s)
- Yufeng Cai
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Wazo Myint
- Department of Structural Biology, School of Medicine, University of Pittsburgh Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
| | - Rieko Ishima
- Department of Structural Biology, School of Medicine, University of Pittsburgh Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15260, USA
- Co-Corresponding authors: Celia A. Schiffer Phone: (508) 856-8008. Rieko Ishima Phone: (412) 648-9056
| | - Celia A. Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
- Co-Corresponding authors: Celia A. Schiffer Phone: (508) 856-8008. Rieko Ishima Phone: (412) 648-9056
| |
Collapse
|