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Singh S, Ghosh P, Roy R, Behera A, Sahadevan R, Kar P, Sadhukhan S, Sonawane A. 4″-Alkyl EGCG Derivatives Induce Cytoprotective Autophagy Response by Inhibiting EGFR in Glioblastoma Cells. ACS OMEGA 2024; 9:2286-2301. [PMID: 38250397 PMCID: PMC10795032 DOI: 10.1021/acsomega.3c06110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/08/2023] [Accepted: 11/16/2023] [Indexed: 01/23/2024]
Abstract
Epidermal growth factor receptor (EGFR)-targeted therapy has been proven vital in the last two decades for the treatment of multiple cancer types, including nonsmall cell lung cancer, glioblastoma, breast cancer and head and neck squamous cell carcinoma. Unfortunately, the majority of approved EGFR inhibitors fall into the drug resistance category because of continuous mutations and acquired resistance. Recently, autophagy has surfaced as one of the emerging underlying mechanisms behind resistance to EGFR-tyrosine kinase inhibitors (TKIs). Previously, we developed a series of 4″-alkyl EGCG (4″-Cn EGCG, n = 6, 8, 10, 12, 14, 16, and 18) derivatives with enhanced anticancer effects and stability. Therefore, the current study hypothesized that 4″-alkyl EGCG might induce cytoprotective autophagy upon EGFR inhibition, and inhibition of autophagy may lead to improved cytotoxicity. In this study, we have observed growth inhibition and caspase-3-dependent apoptosis in 4″-alkyl EGCG derivative-treated glioblastoma cells (U87-MG). We also confirmed that 4″-alkyl EGCG could inhibit EGFR in the cells, as well as mutant L858R/T790M EGFR, through an in vitro kinase assay. Furthermore, we have found that EGFR inhibition with 4″-alkyl EGCG induces cytoprotective autophagic responses, accompanied by the blockage of the AKT/mTOR signaling pathway. In addition, cytotoxicity caused by 4″-C10 EGCG, 4″-C12 EGCG, and 4″-C14 EGCG was significantly increased after the inhibition of autophagy by the pharmacological inhibitor chloroquine. These findings enhance our understanding of the autophagic response toward EGFR inhibitors in glioblastoma cells and suggest a potent combinatorial strategy to increase the therapeutic effectiveness of EGFR-TKIs.
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Affiliation(s)
- Satyam Singh
- Department
of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh 453 552, India
| | - Priya Ghosh
- Department
of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh 453 552, India
| | - Rajarshi Roy
- Department
of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh 453 552, India
| | - Ananyaashree Behera
- School
of Biotechnology, KIIT Deemed to be University, Bhubaneswar, Orissa 751 024, India
| | - Revathy Sahadevan
- Department
of Chemistry, Indian Institute of Technology
Palakkad, Palakkad, Kerala 678 623, India
| | - Parimal Kar
- Department
of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh 453 552, India
| | - Sushabhan Sadhukhan
- Department
of Chemistry, Indian Institute of Technology
Palakkad, Palakkad, Kerala 678 623, India
| | - Avinash Sonawane
- Department
of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh 453 552, India
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Chmielewski D, Wilson EA, Pintilie G, Zhao P, Chen M, Schmid MF, Simmons G, Wells L, Jin J, Singharoy A, Chiu W. Structural insights into the modulation of coronavirus spike tilting and infectivity by hinge glycans. Nat Commun 2023; 14:7175. [PMID: 37935678 PMCID: PMC10630519 DOI: 10.1038/s41467-023-42836-9] [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: 02/05/2023] [Accepted: 10/23/2023] [Indexed: 11/09/2023] Open
Abstract
Coronavirus spike glycoproteins presented on the virion surface mediate receptor binding, and membrane fusion during virus entry and constitute the primary target for vaccine and drug development. How the structure dynamics of the full-length spikes incorporated in viral lipid envelope correlates with the virus infectivity remains poorly understood. Here we present structures and distributions of native spike conformations on vitrified human coronavirus NL63 (HCoV-NL63) virions without chemical fixation by cryogenic electron tomography (cryoET) and subtomogram averaging, along with site-specific glycan composition and occupancy determined by mass spectrometry. The higher oligomannose glycan shield on HCoV-NL63 spikes than on SARS-CoV-2 spikes correlates with stronger immune evasion of HCoV-NL63. Incorporation of cryoET-derived native spike conformations into all-atom molecular dynamic simulations elucidate the conformational landscape of the glycosylated, full-length spike that reveals a role of hinge glycans in modulating spike bending. We show that glycosylation at N1242 at the upper portion of the stalk is responsible for the extensive orientational freedom of the spike crown. Subsequent infectivity assays implicated involvement of N1242-glyan in virus entry. Our results suggest a potential therapeutic target site for HCoV-NL63.
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Affiliation(s)
- David Chmielewski
- Biophysics Graduate Program, Stanford University, Stanford, CA, 94305, USA
| | - Eric A Wilson
- School of Molecular Sciences, Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Grigore Pintilie
- Department of Bioengineering, and of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA
| | - Peng Zhao
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Muyuan Chen
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA
| | - Graham Simmons
- Vitalant Research Institute, San Francisco, CA, 94118, USA
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Lance Wells
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Jing Jin
- Department of Bioengineering, and of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA.
- Vitalant Research Institute, San Francisco, CA, 94118, USA.
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, 94143, USA.
| | - Abhishek Singharoy
- School of Molecular Sciences, Biodesign Institute, Arizona State University, Tempe, AZ, USA.
| | - Wah Chiu
- Biophysics Graduate Program, Stanford University, Stanford, CA, 94305, USA.
- Department of Bioengineering, and of Microbiology and Immunology, Stanford University, Stanford, CA, 94305, USA.
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, 94025, USA.
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Poddar S, Roy R, Kar P. Elucidating the conformational dynamics of histo-blood group antigens and their interactions with the rotavirus spike protein through computational lens. J Biomol Struct Dyn 2023:1-15. [PMID: 37909470 DOI: 10.1080/07391102.2023.2274979] [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: 09/19/2023] [Accepted: 10/18/2023] [Indexed: 11/03/2023]
Abstract
In the present study, we investigated the conformational dynamics of histo-blood group antigens (HBGAs) and their interactions with the VP8* domain of four rotavirus genotypes (P[4], P[6], P[19], and P[11]) utilizing all-atom molecular dynamics simulations in explicit water. Our study revealed distinct changes in the dynamic behavior of the same glycan due to linkage variations. We observed that LNFPI HBGA having a terminal β linkage shows two dominant conformations after complexation, whereas only one was obtained for LNFPI with a terminal α linkage. Interestingly, both variants displayed a single dominant structure in the free state. Similarly, LNT and LNnT show a shift in their dihedral linkage profile between their two terminal monosaccharides because of a change in the linkage from β(1-3) to β(1-4). The molecular mechanics generalized Born surface area (MM/GBSA) calculations yielded the highest binding affinity for LNFPI(β)/P[6] (-13.93 kcal/mol) due to the formation of numerous hydrogen bonds between VP8* and HBGAs. LNnT binds more strongly to P[11] (-12.88 kcal/mol) than LNT (-4.41 kcal/mol), suggesting a single change in the glycan linkage might impact its binding profile significantly. We have also identified critical amino acids and monosaccharides (Gal and GlcNAc) that contributed significantly to the protein-ligand binding through the per-residue decomposition of binding free energy. Moreover, we found that the interaction between the same glycan and different protein receptors within the same rotavirus genogroup influenced the micro-level dynamics of the glycan. Overall, our study helps a deeper understanding of the H-type HBGA and rotavirus spike protein interaction.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sayan Poddar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Rajarshi Roy
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
| | - Parimal Kar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, India
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Roy R, Poddar S, Kar P. Comparison of the conformational dynamics of an N-glycan in implicit and explicit solvents. Carbohydr Res 2022; 522:108700. [DOI: 10.1016/j.carres.2022.108700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/28/2022]
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Grothaus IL, Bussi G, Colombi Ciacchi L. Exploration, Representation, and Rationalization of the Conformational Phase Space of N-Glycans. J Chem Inf Model 2022; 62:4992-5008. [PMID: 36179122 DOI: 10.1021/acs.jcim.2c01049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Despite their fundamental biological relevance, structure-property relationships in N-glycans are fundamentally lacking, and their highly multidimensional compositional and conformational phase spaces remain largely unexplored. The torsional flexibility of the glycosidic linkages and the ring dynamics result in wide, rugged free-energy landscapes that are difficult to sample in molecular dynamics simulations. We show that a novel enhanced-sampling scheme combining replica exchange with solute and collective-variable tempering, enabling transitions over all relevant energy barriers, delivers converged distributions of solvated N-glycan conformers. Several dimensionality-reduction algorithms are compared and employed to generate conformational free-energy maps in two dimensions. Together with an originally developed conformation-based nomenclature scheme that uniquely identifies glycan conformers, our modeling procedure is applied to reveal the effect of chemical substitutions on the conformational ensemble of selected high-mannose-type and complex glycans. Moreover, the structure-prediction capabilities of two commonly used glycan force fields are assessed via the theoretical prediction of experimentally available nuclear magnetic resonance J-coupling constants. The results especially confirm the key role of ω and ψ torsion angles in discriminating between different conformational states and suggest an intriguing correlation between the torsional and ring-puckering degrees of freedom that may be biologically relevant.
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Affiliation(s)
- Isabell Louise Grothaus
- Hybrid Materials Interfaces Group, Bremen Center for Computational Materials Science and MAPEX Center for Materials and Processes, University of Bremen, 28359Bremen, Germany
| | - Giovanni Bussi
- Scuola Internazionale Superiore di Studi Avanzati (SISSA), 34136Trieste, Italy
| | - Lucio Colombi Ciacchi
- Hybrid Materials Interfaces Group, Bremen Center for Computational Materials Science and MAPEX Center for Materials and Processes, University of Bremen, 28359Bremen, Germany
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Roy R, Jonniya NA, Kar P. Effect of Sulfation on the Conformational Dynamics of Dermatan Sulfate Glycosaminoglycan: A Gaussian Accelerated Molecular Dynamics Study. J Phys Chem B 2022; 126:3852-3866. [PMID: 35594147 DOI: 10.1021/acs.jpcb.2c01807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Glycosaminoglycans (GAGs) are anionic biopolymers present on cell surfaces as a part of proteoglycans. The biological activities of GAGs depend on the sulfation pattern. In our study, we have considered three octadecasaccharide dermatan sulfate (DS) chains with increasing order of sulfation (dp6s, dp7s, and dp12s) to illuminate the role of sulfation on the GAG units and its chain conformation through 10 μs-long Gaussian accelerated molecular dynamics simulations. DS is composed of repeating disaccharide units of iduronic acid (IdoA) and N-acetylgalactosamine (N-GalNAc). Here, N-GalNAc is linked to IdoA via β(1-4), while IdoA is linked to N-GalNAc through α(1-3). With the increase in sulfation, the DS structure becomes more rigid and linear, as is evident from the distribution of root-mean-square deviations (RMSDs) and end-to-end distances. The tetrasaccharide linker region of the main chain shows a rigid conformation in terms of the glycosidic linkage. We have observed that upon sulfation (i.e., dp12s), the ring flip between two chair forms vanished for IdoA. The dynamic cross-correlation analysis reveals that the anticorrelation motions in dp12s are reduced significantly compared to dp6s or dp7s. An increase in sulfation generates relatively more stable hydrogen-bond networks, including water bridging with the neighboring monosaccharides. Despite the favorable linear structures of the GAG chains, our study also predicts few significant bendings related to the different puckering states, which may play a notable role in the function of the DS. The relation between the global conformation with the micro-level parameters such as puckering and water-mediated hydrogen bonds shapes the overall conformational space of GAGs. Overall, atomistic details of the DS chain provided in this study will help understand their functional and mechanical roles, besides developing new biomaterials.
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Affiliation(s)
- Rajarshi Roy
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Nisha Amarnath Jonniya
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore 453552, Madhya Pradesh, India
| | - Parimal Kar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Khandwa Road, Indore 453552, Madhya Pradesh, India
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Roy R, Jonniya NA, Sk MF, Kar P. Comparative Structural Dynamics of Isoforms of Helicobacter pylori Adhesin BabA Bound to Lewis b Hexasaccharide via Multiple Replica Molecular Dynamics Simulations. Front Mol Biosci 2022; 9:852895. [PMID: 35586194 PMCID: PMC9108286 DOI: 10.3389/fmolb.2022.852895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022] Open
Abstract
BabA of Helicobacter pylori is the ABO blood group antigen-binding adhesin. Despite considerable diversity in the BabA sequence, it shows an extraordinary adaptation in attachment to mucosal layers. In the current study, multiple replica molecular dynamics simulations were conducted in a neutral aqueous solution to elucidate the conformational landscape of isoforms of BabA bound to Lewis b (Leb) hexasaccharide. In addition, we also investigated the underlying molecular mechanism of the BabA-glycan complexation using the MM/GBSA scheme. The conformational dynamics of Leb in the free and protein-bound states were also studied. The carbohydrate-binding site across the four isoforms was examined, and the conformational variability of several vital loops was observed. The cysteine–cysteine loops and the two diversity loops (DL1 and DL2) were identified to play an essential role in recognizing the glycan molecule. The flexible crown region of BabA was stabilized after association with Leb. The outward movement of the DL2 loop vanished upon ligand binding for the Spanish specialist strain (S381). Our study revealed that the S831 strain shows a stronger affinity to Leb than other strains due to an increased favorable intermolecular electrostatic contribution. Furthermore, we showed that the α1-2-linked fucose contributed most to the binding by forming several hydrogen bonds with key amino acids. Finally, we studied the effect of the acidic environment on the BabA-glycan complexation via constant pH MD simulations, which showed a reduction in the binding free energy in the acidic environment. Overall, our study provides a detailed understanding of the molecular mechanism of Leb recognition by four isoforms of H. pylori that may help the development of therapeutics targeted at inhibiting H. pylori adherence to the gastric mucosa.
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