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Sarma H, Sastry GN. A Computational Study on the Interaction of NSP10 and NSP14: Unraveling the RNA Synthesis Proofreading Mechanism in SARS-CoV-2, SARS-CoV, and MERS-CoV. ACS OMEGA 2022; 7:30003-30022. [PMID: 36035077 PMCID: PMC9397572 DOI: 10.1021/acsomega.2c03007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
The interaction of exoribonuclease (ExoN) nonstructural protein (NSP14) with NSP10 co-factors is crucial for high-fidelity proofreading activity of coronavirus replication and transcription. Proofreading function is critical for maintaining the large genomes to ensure replication proficiency; therefore, while maintaining the viral replication fitness, quick resistance has been reported to the nucleotide analogue (NA) drugs. Therefore, targeting the NSP14 and NSP10 interacting interface with small molecules or peptides could be a better strategy to obstruct replication processes of coronaviruses (CoVs). A comparative study on the binding mechanism of NSP10 with the NSP14 ExoN domain of SARS-CoV-2, SARS-CoV, MERS-CoV, and four SARS-CoV-2 NSP14mutant complexes has been carried out. Protein-protein interaction (PPI) dynamics, per-residue binding free energy (BFE) analyses, and the identification of interface hotspot residues have been studied using molecular dynamics simulations and various computational tools. The BFE of the SARS-CoV NSP14-NSP10 complex was higher when compared to novel SARS-CoV-2 and MERS. However, SARS-CoV-2 NSP14mutant systems display a higher BFE as compared to the wild type (WT) but lower than SARS-CoV and MERS. Despite the high BFE, the SARS-CoV NSP14-NSP10 complex appears to be structurally more flexible in many regions especially the catalytic site, which is not seen in SARS-CoV-2 and its mutant or MERS complexes. The significantly high residue energy contribution of key interface residues and hotspots reveals that the high binding energy between NSP14 and NSP10 may enhance the functional activity of the proofreading complex, as the NSP10-NSP14 interaction is essential in maintaining the stability of the ExoN domain for the replicative fitness of CoVs. The factors discussed for SARS-CoV-2 complexes may be responsible for NSP14 ExoN having a high replication proficiency, significantly leading to the evolution of new variants of SARS-CoV-2. The NSP14 residues V66, T69, D126, and I201and eight residues of NSP10 (L16, F19, V21, V42, M44, H80, K93, and F96) are identified as common hotspots. Overall, the interface area, hotspot locations, bonded/nonbonded contacts, and energies between NSP14 and NSP10 may pave a way in designing potential inhibitors to disrupt NSP14-NSP10 interactions of CoVs especially SARS-CoV-2.
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Affiliation(s)
- Himakshi Sarma
- Advanced Computation and Data Sciences Division,
CSIR−North East Institute of Science and Technology,
Jorhat, Assam785006, India
| | - G. Narahari Sastry
- Advanced Computation and Data Sciences Division,
CSIR−North East Institute of Science and Technology,
Jorhat, Assam785006, India
- Academy of Scientific and Innovative
Research (AcSIR), Ghaziabad 201002, India
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Sarma H, Jamir E, Sastry GN. Protein-protein interaction of RdRp with its co-factor NSP8 and NSP7 to decipher the interface hotspot residues for drug targeting: A comparison between SARS-CoV-2 and SARS-CoV. J Mol Struct 2022; 1257:132602. [PMID: 35153334 PMCID: PMC8824464 DOI: 10.1016/j.molstruc.2022.132602] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 02/09/2023]
Abstract
In this study we explored the molecular mechanism of RdRp (Non-Structural Protein, NSP12) interaction with its co-factors NSP7 and NSP8 which is the main toolbox for RNA replication and transcription of SARS-CoV-2 and SARS-CoV. The replication complex is a heterotetramer consists of one NSP12, one NSP7 and two NSP8. Extensive molecular dynamics (MD) simulations were applied on both the heterotetramer complexes to generate the conformations and were used to estimate the MMPBSA binding free energy (BFE) and per-residue energy decomposition of NSP12-NSP8 and NSP12-NSP7 and NSP7-NSP8 complexes. The BFE of SARS-CoV-2 heterotetramer complex with its corresponding partner protein was significantly higher as compared to SARS-CoV. Interface hotspot residues were predicted using different methods implemented in KFC (Knowledge-based FADA and Contracts), HotRegion and Robetta web servers. Per-residue energy decomposition analysis showed that the predicted interface hotspot residues contribute more energy towards the formation of complexes and most of the predicted hotspot residues are clustered together. However, there is a slight difference in the residue-wise energy contribution in the interface NSPs on heterotetramer viral replication complex of both coronaviruses. While the overall replication complex of SARS-CoV-2 was found to be slightly flexible as compared to SARS-CoV. This difference in terms of structural flexibility/stability and energetic characteristics of interface residues including hotspots at PPI interface in the viral replication complexes may be the reason of higher rate of RNA replication of SARS-CoV-2 as compared to SARS-CoV. Overall, the interaction profile at PPI interface such as, interface area, hotspot residues, nature of bonds and energies between NSPs, may provide valuable insights in designing of small molecules or peptide/peptidomimetic ligands which can fit into the PPI interface to disrupt the interaction.
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Affiliation(s)
- Himakshi Sarma
- Advanced Computation and Data Sciences Division, CSIR - North East Institute of Science and Technology, Jorhat, Assam, India
| | - Esther Jamir
- Advanced Computation and Data Sciences Division, CSIR - North East Institute of Science and Technology, Jorhat, Assam, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - G Narahari Sastry
- Advanced Computation and Data Sciences Division, CSIR - North East Institute of Science and Technology, Jorhat, Assam, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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Investigation of glutathione as a natural antioxidant and multitarget inhibitor for Alzheimer’s disease: Insights from molecular simulations. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117960] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Pant S, Singh M, Ravichandiran V, Murty USN, Srivastava HK. Peptide-like and small-molecule inhibitors against Covid-19. J Biomol Struct Dyn 2021; 39:2904-2913. [PMID: 32306822 PMCID: PMC7212534 DOI: 10.1080/07391102.2020.1757510] [Citation(s) in RCA: 204] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 04/14/2020] [Indexed: 12/13/2022]
Abstract
Coronavirus disease strain (SARS-CoV-2) was discovered in 2019, and it is spreading very fast around the world causing the disease Covid-19. Currently, more than 1.6 million individuals are infected, and several thousand are dead across the globe because of Covid-19. Here, we utilized the in-silico approaches to identify possible protease inhibitors against SARS-CoV-2. Potential compounds were screened from the CHEMBL database, ZINC database, FDA approved drugs and molecules under clinical trials. Our study is based on 6Y2F and 6W63 co-crystallized structures available in the protein data bank (PDB). Seven hundred compounds from ZINC/CHEMBL databases and fourteen hundred compounds from drug-bank were selected based on positive interactions with the reported binding site. All the selected compounds were subjected to standard-precision (SP) and extra-precision (XP) mode of docking. Generated docked poses were carefully visualized for known interactions within the binding site. Molecular mechanics-generalized born surface area (MM-GBSA) calculations were performed to screen the best compounds based on docking scores and binding energy values. Molecular dynamics (MD) simulations were carried out on four selected compounds from the CHEMBL database to validate the stability and interactions. MD simulations were also performed on the PDB structure 6YF2F to understand the differences between screened molecules and co-crystallized ligand. We screened 300 potential compounds from various databases, and 66 potential compounds from FDA approved drugs. Cobicistat, ritonavir, lopinavir, and darunavir are in the top screened molecules from FDA approved drugs. The screened drugs and molecules may be helpful in fighting with SARS-CoV-2 after further studies.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Suyash Pant
- Department of Pharmacoinformatics, National
Institute of Pharmaceutical Education and Research Kolkata, Kolkata, West
Bengal, India
| | - Meenakshi Singh
- Department of Natural Products, National
Institute of Pharmaceutical Education and Research Kolkata, Kolkata, West
Bengal, India
| | - V. Ravichandiran
- Department of Natural Products, National
Institute of Pharmaceutical Education and Research Kolkata, Kolkata, West
Bengal, India
| | - U. S. N. Murty
- Department of Medicinal Chemistry, National
Institute of Pharmaceutical Education and Research Guwahati, Guwahati,
Assam, India
| | - Hemant Kumar Srivastava
- Department of Medicinal Chemistry, National
Institute of Pharmaceutical Education and Research Guwahati, Guwahati,
Assam, India
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Thamaraiselvan V, Velayutham R. The putative binding site and SAR rationalization of small molecules against glucagon-like peptide-1 receptor using homology model and crystal structures: a comparative study. J Biomol Struct Dyn 2020; 40:2038-2052. [PMID: 33118484 DOI: 10.1080/07391102.2020.1835720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) is involved in glucose-stimulated insulin secretion and weight regulating actions through the activation of the GLP-1 receptor (GLP-1R). Clinical effectiveness of GLP-1 mimetics is effective in improving glucose control in patients. Thus, identifying and developing orally active small-molecule agonists are highly desirable. This study summarizes the structure-function relationship of hGLP-1R through computational approaches and search of small molecule GLP-1R agonists. We carried out mutation guided data-driven study, for developing the GLP-1R model to explore and validate the putative site for quinoxaline analogues. The developed GLP-1R homology model was subjected to 500 ns MD simulation for validation. Various snapshots were considered to identify the best structure of GLP-1R based on correlation between experimental pEC50 and various theoretical parameters (docking score, MM-GBSA ΔG bind, WM/MM ΔG bind). The putative binding site (Sitemap and WaterMap has been predicted and it matched well with the available data. Excellent correlation (R2 =0.94), between pEC50 and WM/MM ΔG bind for the snapshot at 350 ns was observed after including induced-fit docking results of the most potent molecule. Enrichment calculation indicates better AUC (=0.75) for predicted complex structure. A comparison of the developed GLP-1R model with the available crystal structure shows excellent similarities and it was used for virtual screening to find small molecule agonists. The good correlation of our model with crystal structures of GLP-1R may help to understand the structure-function relationship of other secretin families.
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Affiliation(s)
| | - Ravichandiran Velayutham
- Department of Natural Products, National Institute of Pharmaceutical Education and Research, Kolkata, India
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Modeling antimalarial and antihuman African trypanosomiasis compounds: a ligand- and structure-based approaches. Mol Divers 2019; 24:1107-1124. [PMID: 31760561 DOI: 10.1007/s11030-019-10015-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/06/2019] [Indexed: 02/07/2023]
Abstract
This study examines the interaction of 137 antimalarial and antihuman African trypanosomiasis compounds [bis(2-aminoimidazolines), bisguanidinediphenyls and polyamines] on three different in vitro assays (Trypanosoma brucei rhodesiense (T.b.r.), Plasmodium falciparum (P.f.) and cytotoxicity-L6 cells). ΔTm values, wherever available, were also examined for the considered ligands. Eight DNA-ligand complexes and one DNA structure without ligand were selected from protein data bank (PDB) based on the structural similarity. Geometry optimization of all the considered ligands was carried out at the B3LYP/6-31G(d) level of theory. The AutoDock4 tool was utilized for the docking of these molecules at the minor groove of nine selected DNA crystal structures. We observed DT20, DA6, DT8 and DT19 residues generally interact with most of the considered ligands. Molecular dynamics simulations, molecular mechanics-generalized born surface area and molecular mechanics-Poisson Boltzmann surface area calculations indicate that the docked poses are generally stable and docked ligands do not show much deviation in the minor groove of DNA until 10 ns simulation. Efficient and statistically significant quantitative structure-activity relationship models for T.b.r., P.f., C-L6 and ΔTm values were developed. All the generated models are internally and externally validated. We predicted a few ligands with significant IC50 values against P.f. based on the developed models. These results may help to design new and potent antimalarial and antihuman African trypanosomal compounds.
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Gaur AS, Nagamani S, Tanneeru K, Druzhilovskiy D, Rudik A, Poroikov V, Narahari Sastry G. Molecular property diagnostic suite for diabetes mellitus (MPDSDM): An integrated web portal for drug discovery and drug repurposing. J Biomed Inform 2018; 85:114-125. [DOI: 10.1016/j.jbi.2018.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 07/26/2018] [Accepted: 08/05/2018] [Indexed: 01/08/2023]
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Bignon E, Chan CH, Morell C, Monari A, Ravanat JL, Dumont E. Molecular Dynamics Insights into Polyamine-DNA Binding Modes: Implications for Cross-Link Selectivity. Chemistry 2017; 23:12845-12852. [DOI: 10.1002/chem.201702065] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Emmanuelle Bignon
- Institut des Sciences Analytiques, UMR 5280; Université de Lyon 1 (UCBL) CNRS, ENS Lyon; Lyon France
- Laboratoire de Chimie; Univ Lyon; Ecole Normale Supérieure de Lyon, CNRS UMR 5182; Université Lyon 1; Laboratoire de Chimie; 46 allée d'Italie 69364 Lyon France
| | - Chen-Hui Chan
- Laboratoire de Chimie; Univ Lyon; Ecole Normale Supérieure de Lyon, CNRS UMR 5182; Université Lyon 1; Laboratoire de Chimie; 46 allée d'Italie 69364 Lyon France
| | - Christophe Morell
- Institut des Sciences Analytiques, UMR 5280; Université de Lyon 1 (UCBL) CNRS, ENS Lyon; Lyon France
| | - Antonio Monari
- Université de Lorraine Nancy; Theory-Modeling-Simulation, SRSMC; 54506 Vandoeuvre-lès-Nancy France
- CNRS; UMR 7565, SRSMC; 54506 Vandoeuvre-lès- Nancy France
| | - Jean-Luc Ravanat
- CEA and Université Grenoble Alpes, INAC-SyMMES; 38000 Grenoble France
| | - Elise Dumont
- Laboratoire de Chimie; Univ Lyon; Ecole Normale Supérieure de Lyon, CNRS UMR 5182; Université Lyon 1; Laboratoire de Chimie; 46 allée d'Italie 69364 Lyon France
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Peddi SR, Sivan SK, Manga V. Molecular dynamics and MM/GBSA-integrated protocol probing the correlation between biological activities and binding free energies of HIV-1 TAR RNA inhibitors. J Biomol Struct Dyn 2017; 36:486-503. [PMID: 28081678 DOI: 10.1080/07391102.2017.1281762] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The interaction of HIV-1 transactivator protein Tat with its cognate transactivation response (TAR) RNA has emerged as a promising target for developing antiviral compounds and treating HIV infection, since it is a crucial step for efficient transcription and replication. In the present study, molecular dynamics (MD) simulations and MM/GBSA calculations have been performed on a series of neamine derivatives in order to estimate appropriate MD simulation time for acceptable correlation between ΔGbind and experimental pIC50 values. Initially, all inhibitors were docked into the active site of HIV-1 TAR RNA. Later to explore various conformations and examine the docking results, MD simulations were carried out. Finally, binding free energies were calculated using MM/GBSA method and were correlated with experimental pIC50 values at different time scales (0-1 to 0-10 ns). From this study, it is clear that in case of neamine derivatives as simulation time increased the correlation between binding free energy and experimental pIC50 values increased correspondingly. Therefore, the binding energies which can be interpreted at longer simulation times can be used to predict the bioactivity of new neamine derivatives. Moreover, in this work, we have identified some plausible critical nucleotide interactions with neamine derivatives that are responsible for potent inhibitory activity. Furthermore, we also provide some insights into a new class of oxadiazole-based back bone cyclic peptides designed by incorporating the structural features of neamine derivatives. On the whole, this approach can provide a valuable guidance for designing new potent inhibitors and modify the existing compounds targeting HIV-1 TAR RNA.
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Affiliation(s)
- Saikiran Reddy Peddi
- a Molecular Modeling and Medicinal Chemistry Group, Department of Chemistry , University College of Science, Osmania University , Hyderabad 500 007 , Telangana , India
| | - Sree Kanth Sivan
- b Department of Chemistry , Nizam College, Osmania University , Hyderabad 500 001 , Telangana , India
| | - Vijjulatha Manga
- a Molecular Modeling and Medicinal Chemistry Group, Department of Chemistry , University College of Science, Osmania University , Hyderabad 500 007 , Telangana , India
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Broomhead NK, Soliman ME. Can We Rely on Computational Predictions To Correctly Identify Ligand Binding Sites on Novel Protein Drug Targets? Assessment of Binding Site Prediction Methods and a Protocol for Validation of Predicted Binding Sites. Cell Biochem Biophys 2016; 75:15-23. [PMID: 27796788 DOI: 10.1007/s12013-016-0769-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 10/19/2016] [Indexed: 11/30/2022]
Abstract
In the field of medicinal chemistry there is increasing focus on identifying key proteins whose biochemical functions can firmly be linked to serious diseases. Such proteins become targets for drug or inhibitor molecules that could treat or halt the disease through therapeutic action or by blocking the protein function respectively. The protein must be targeted at the relevant biologically active site for drug or inhibitor binding to be effective. As insufficient experimental data is available to confirm the biologically active binding site for novel protein targets, researchers often rely on computational prediction methods to identify binding sites. Presented herein is a short review on structure-based computational methods that (i) predict putative binding sites and (ii) assess the druggability of predicted binding sites on protein targets. This review briefly covers the principles upon which these methods are based, where they can be accessed and their reliability in identifying the correct binding site on a protein target. Based on this review, we believe that these methods are useful in predicting putative binding sites, but as they do not account for the dynamic nature of protein-ligand binding interactions, they cannot definitively identify the correct site from a ranked list of putative sites. To overcome this shortcoming, we strongly recommend using molecular docking to predict the most likely protein-ligand binding site(s) and mode(s), followed by molecular dynamics simulations and binding thermodynamics calculations to validate the docking results. This protocol provides a valuable platform for experimental and computational efforts to design novel drugs and inhibitors that target disease-related proteins.
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Affiliation(s)
- Neal K Broomhead
- Molecular Modelling & Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal, Westville, Durban, 4001, South Africa
| | - Mahmoud E Soliman
- Molecular Modelling & Drug Design Research Group, School of Health Sciences, University of KwaZulu-Natal, Westville, Durban, 4001, South Africa.
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Niu Y, Pan D, Shi D, Bai Q, Liu H, Yao X. Influence of Chirality of Crizotinib on Its MTH1 Protein Inhibitory Activity: Insight from Molecular Dynamics Simulations and Binding Free Energy Calculations. PLoS One 2015; 10:e0145219. [PMID: 26677850 PMCID: PMC4683072 DOI: 10.1371/journal.pone.0145219] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 11/30/2015] [Indexed: 12/12/2022] Open
Abstract
As a promising target for the treatment of lung cancer, the MutT Homolog 1 (MTH1) protein can be inhibited by crizotinib. A recent work shows that the inhibitory potency of (S)-crizotinib against MTH1 is about 20 times over that of (R)-crizotinib. But the detailed molecular mechanism remains unclear. In this study, molecular dynamics (MD) simulations and free energy calculations were used to elucidate the mechanism about the effect of chirality of crizotinib on the inhibitory activity against MTH1. The binding free energy of (S)-crizotinib predicted by the Molecular Mechanics/Generalized Born Surface Area (MM/GBSA) and Adaptive biasing force (ABF) methodologies is much lower than that of (R)-crizotinib, which is consistent with the experimental data. The analysis of the individual energy terms suggests that the van der Waals interactions are important for distinguishing the binding of (S)-crizotinib and (R)-crizotinib. The binding free energy decomposition analysis illustrated that residues Tyr7, Phe27, Phe72 and Trp117 were important for the selective binding of (S)-crizotinib to MTH1. The adaptive biasing force (ABF) method was further employed to elucidate the unbinding process of (S)-crizotinib and (R)-crizotinib from the binding pocket of MTH1. ABF simulation results suggest that the reaction coordinates of the (S)-crizotinib from the binding pocket is different from (R)-crizotinib. The results from our study can reveal the details about the effect of chirality on the inhibition activity of crizotinib to MTH1 and provide valuable information for the design of more potent inhibitors.
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Affiliation(s)
- Yuzhen Niu
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, 730000, China
| | - Dabo Pan
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, 730000, China
| | - Danfeng Shi
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, 730000, China
| | - Qifeng Bai
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, 730000, China
| | - Huanxiang Liu
- School of Pharmacy, Lanzhou University, Lanzhou, 730000, China
- The Separating Scientific Institute of Lanzhou, Lanzhou, 730000, China
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, 730000, China
- Key Lab of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, 730000, China
- * E-mail:
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Appell M, Bosma WB. Assessment of the electronic structure and properties of trichothecene toxins using density functional theory. JOURNAL OF HAZARDOUS MATERIALS 2015; 288:113-123. [PMID: 25698572 DOI: 10.1016/j.jhazmat.2015.01.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 01/17/2015] [Accepted: 01/21/2015] [Indexed: 06/04/2023]
Abstract
A comprehensive quantum chemical study was carried out on 35 type A and B trichothecenes and biosynthetic precursors, including selected derivatives of deoxynivalenol and T-2 toxin. Quantum chemical properties, Natural Bond Orbital (NBO) analysis, and molecular parameters were calculated on structures geometry optimized at the B3LYP/6-311+G** level. Type B trichothecenes possessed significantly larger electrophilicity index compared to the type A trichothecenes studied. Certain hydroxyl groups of deoxynivalenol, nivalenol, and T-2 toxin exhibited considerable rotation during molecular dynamics simulations (5 ps) at the B3LYP/6-31G** level in implicit aqueous solvent. Quantitative structure activity relationship (QSAR) models were developed to evaluate toxicity and detection using genetic algorithm, principal component, and multilinear analyses. The models suggest electronegativity and several 2-dimensional topological descriptors contain important information related to trichothecene cytotoxicity, phytotoxicity, immunochemical detection, and cross-reactivity.
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Affiliation(s)
- Michael Appell
- Bacterial Foodborne Pathogens and Mycology Research USDA, ARS, National Center for Agricultural Utilization Research 1815 N. University St., Peoria, IL 61604, USA.
| | - Wayne B Bosma
- Mund-Lagowski Department of Chemistry and Biochemistry Bradley University 1501 W. Bradley Ave., Peoria, IL 61625, USA.
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Yadav RK, Yadava U. Molecular dynamics simulation of hydrated d(CGGGTACCCG)4as a four-way DNA Holliday junction and comparison with the crystallographic structure. MOLECULAR SIMULATION 2015. [DOI: 10.1080/08927022.2015.1007052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Srivastava HK, Sastry GN. Molecular dynamics investigation on a series of HIV protease inhibitors: assessing the performance of MM-PBSA and MM-GBSA approaches. J Chem Inf Model 2012; 52:3088-98. [PMID: 23121465 DOI: 10.1021/ci300385h] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The binding free energies (ΔG(Bind)) obtained from molecular mechanics with Poisson-Boltzmann surface area (MM-PBSA) or molecular mechanics with Generalized Born surface area (MM-GBSA) calculations using molecular dynamics (MD) trajectories are the most popular procedures to measure the strength of interactions between a ligand and its receptor. Several attempts have been made to correlate the ΔG(Bind) and experimental IC(50) values in order to observe the relationship between binding strength of a ligand (with its receptor) and its inhibitory activity. The duration of MD simulations seems very important for getting acceptable correlation. Here, we are presenting a systematic study to estimate the reasonable MD simulation time for acceptable correlation between ΔG(Bind) and experimental IC(50) values. A comparison between MM-PBSA and MM-GBSA approaches is also presented at various time scales. MD simulations (10 ns) for 14 HIV protease inhibitors have been carried out by using the Amber program. MM-PBSA/GBSA based ΔG(Bind) have been calculated and correlated with experimental IC(50) values at different time scales (0-1 to 0-10 ns). This study clearly demonstrates that the MM-PBSA based ΔG(Bind) (ΔG(Bind)-PB) values provide very good correlation with experimental IC(50) values (quantitative and qualitative) when MD simulation is carried out for a longer time; however, MM-GBSA based ΔG(Bind) (ΔG(Bind)-GB) values show acceptable correlation for shorter time of simulation also. The accuracy of ΔG(Bind)-PB increases and ΔG(Bind)-GB remains almost constant with the increasing time of simulation.
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Affiliation(s)
- Hemant Kumar Srivastava
- Centre for Molecular Modelling, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 607, India
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