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Yuan R, Huang H. Anchoring of Amyloid-β onto Polyunsaturated Phospholipid Membranes. J Biomol Struct Dyn 2023; 41:1098-1108. [PMID: 34915817 DOI: 10.1080/07391102.2021.2016488] [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: 01/11/2023]
Abstract
The interaction between the toxic amyloid-β and phospholipid membranes in the early stage of Alzheimer's disease is complicated and depends on many factors. It was found that polyunsaturated fatty acids affect the incidence of Alzheimer's disease. The number of double bonds in the phospholipid layer may play an important role in the molecular dynamic behavior of amyloid-β on cell membranes. In the present paper, the interactions between Aβ(25-35) and each of four phospholipids, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1-stearoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (SAPC), 1-stearoyl-2-docosahexaenooyl-sn-glycero-3-phosphocholine (SDPC), and 1,2-diarachidonoyl-sn-glycero-3-phosphocholine (DAPC), are investigated by using all-atom molecular dynamics simulation. It is interesting that, as the number of double bonds in the membrane increases, the peptide fragment prefers to stay in the surface region of the membrane rather than penetrates deeply into the membrane. With the increasing number of double bonds, the interaction between Aβ(25-35) and the membrane surface becomes stronger, especially for the interaction between the residue 28 (LYS28) in Aβ(25-35) and the phospholipids, anchoring Aβ(25-35) onto the membrane. The double bonds in phospholipid determine not only the adsorption of the peptide fragment Aβ(25-35) but also its conformation, which will influence further aggregation of Aβ in later stages.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Ruikang Yuan
- Laboratory of Soft Matter, South China University of Technology, Guangzhou, China
| | - Haohao Huang
- Laboratory of Soft Matter, South China University of Technology, Guangzhou, China
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Muller MP, Jiang T, Sun C, Lihan M, Pant S, Mahinthichaichan P, Trifan A, Tajkhorshid E. Characterization of Lipid-Protein Interactions and Lipid-Mediated Modulation of Membrane Protein Function through Molecular Simulation. Chem Rev 2019; 119:6086-6161. [PMID: 30978005 PMCID: PMC6506392 DOI: 10.1021/acs.chemrev.8b00608] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The cellular membrane constitutes one of the most fundamental compartments of a living cell, where key processes such as selective transport of material and exchange of information between the cell and its environment are mediated by proteins that are closely associated with the membrane. The heterogeneity of lipid composition of biological membranes and the effect of lipid molecules on the structure, dynamics, and function of membrane proteins are now widely recognized. Characterization of these functionally important lipid-protein interactions with experimental techniques is however still prohibitively challenging. Molecular dynamics (MD) simulations offer a powerful complementary approach with sufficient temporal and spatial resolutions to gain atomic-level structural information and energetics on lipid-protein interactions. In this review, we aim to provide a broad survey of MD simulations focusing on exploring lipid-protein interactions and characterizing lipid-modulated protein structure and dynamics that have been successful in providing novel insight into the mechanism of membrane protein function.
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Affiliation(s)
- Melanie P. Muller
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Tao Jiang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chang Sun
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Muyun Lihan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Shashank Pant
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Paween Mahinthichaichan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anda Trifan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology
- Department of Biochemistry
- Center for Biophysics and Quantitative Biology
- College of Medicine
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Dutagaci B, Feig M. Determination of Hydrophobic Lengths of Membrane Proteins with the HDGB Implicit Membrane Model. J Chem Inf Model 2017; 57:3032-3042. [PMID: 29155578 DOI: 10.1021/acs.jcim.7b00510] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A protocol for predicting the hydrophobic length of membrane proteins using the heterogeneous dielectric generalized Born (HDGB) implicit membrane model is presented. The method involves optimal positioning in the membrane and identification of lipid-facing and inward-facing residues, followed by energy optimization of the implicit membrane model to obtain the hydrophobic length from the optimal membrane width. The latest HDGB version 3 (HDGBv3) and HDGB van der Waals (HDGBvdW) models were applied to a test set containing 15 proteins (seven β-barrel and eight α-helical proteins), for which matching membrane widths are available from experiment, and an additional set contains ten α-helical and ten β-barrel proteins without any experimental data. The results with the HDGB model compare favorably with predictions from methods used in the Orientations of Proteins in Membranes (OPM) and Protein Data Bank of Transmembrane Proteins (PDB-TM) databases.
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Affiliation(s)
- Bercem Dutagaci
- Department of Biochemistry and Molecular Biology, Michigan State University , 603 Wilson Road, Room BCH, 218, East Lansing, Michigan 48824, United States
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University , 603 Wilson Road, Room BCH, 218, East Lansing, Michigan 48824, United States
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Tena-Campos M, Ramon E, Lupala CS, Pérez JJ, Koch KW, Garriga P. Zinc Is Involved in Depression by Modulating G Protein-Coupled Receptor Heterodimerization. Mol Neurobiol 2015; 53:2003-2015. [PMID: 25855059 DOI: 10.1007/s12035-015-9153-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 03/19/2015] [Indexed: 12/01/2022]
Abstract
5-Hydroxytryptamine 1A receptor and galanin receptor 1 belong to the G protein-coupled receptors superfamily, and they have been described to heterodimerize triggering an anomalous physiological state that would underlie depression. Zinc supplementation has been widely reported to improve treatment against major depressive disorder. Our work has focused on the study and characterization of these receptors and its relationships with zinc both under purified conditions and in cell culture. To this aim, we have designed a strategy to purify the receptors in a conformationally active state. We have used receptors tagged with the monoclonal Rho-1D4 antibody and employed ligand-assisted purification in order to successfully purify both receptors in a properly folded and active state. The interaction between both purified receptors has been analyzed by surface plasmon resonance in order to determine the kinetics of dimerization. Zinc effect on heteromer has also been tested using the same methodology but exposing the 5-hydroxytryptamine 1A receptor to zinc before the binding experiment. These results, combined with Förster resonance energy transfer (FRET) measurements, in the absence and presence of zinc, suggest that this ion is capable of disrupting this interaction. Moreover, molecular modeling suggests that there is a coincidence between zinc-binding sites and heterodimerization interfaces for the serotonin receptor. Our results establish a rational explanation for the role of zinc in the molecular processes associated with receptor-receptor interactions and its relationship with depression, in agreement with previously reported evidence for the positive effects of zinc in depression treatment, and the involvement of our target dimer in the same disease.
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Affiliation(s)
- Mercè Tena-Campos
- Departament d'Enginyeria Química, Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Edifici Gaia, Rambla de Sant Nebridi 22, 08222, Terrassa, Catalonia, Spain
| | - Eva Ramon
- Departament d'Enginyeria Química, Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Edifici Gaia, Rambla de Sant Nebridi 22, 08222, Terrassa, Catalonia, Spain
| | - Cecylia S Lupala
- Departament d'Enginyeria Química, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, ETSEIB, Avda. Diagonal 647, 08028, Barcelona, Catalonia, Spain
| | - Juan J Pérez
- Departament d'Enginyeria Química, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, ETSEIB, Avda. Diagonal 647, 08028, Barcelona, Catalonia, Spain
| | - Karl-W Koch
- Department of Neurosciences, Biochemistry Group, University of Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129, Oldenburg, Germany
| | - Pere Garriga
- Departament d'Enginyeria Química, Grup de Biotecnologia Molecular i Industrial, Centre de Biotecnologia Molecular, Universitat Politècnica de Catalunya, Edifici Gaia, Rambla de Sant Nebridi 22, 08222, Terrassa, Catalonia, Spain.
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Effect of temperature on the phase behaviour of fully saturated DAPC lipid bilayer: a comparative molecular dynamics simulation study. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014. [PMID: 25408349 DOI: 10.1007/978-3-319-11280-0_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
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6
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Assembly and stability of Salmonella enterica ser. Typhi TolC protein in POPE and DMPE. J Biol Phys 2014; 40:387-400. [PMID: 25011632 DOI: 10.1007/s10867-014-9357-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022] Open
Abstract
In this work we assessed the suitability of two different lipid membranes for the simulation of a TolC protein from Salmonella enterica serovar Typhi. The TolC protein family is found in many pathogenic Gram-negative bacteria including Vibrio cholera and Pseudomonas aeruginosa and acts as an outer membrane channel for expulsion of drug and toxin from the cell. In S. typhi, the causative agent for typhoid fever, the TolC outer membrane protein is an antigen for the pathogen. The lipid environment is an important modulator of membrane protein structure and function. We evaluated the conformation of the TolC protein in the presence of DMPE and POPE bilayers using molecular dynamics simulation. The S. typhi TolC protein exhibited similar conformational dynamics to TolC and its homologues. Conformational flexibility of the protein is seen in the C-terminal, extracellular loops, and α-helical region. Despite differences in the two lipids, significant similarities in the motion of the protein in POPE and DMPE were observed, including the rotational motion of the C-terminal residues and the partially open extracellular loops. However, analysis of the trajectories demonstrated effects of hydrophobic matching of the TolC protein in the membrane, particularly in the lengthening of the lipids and subtle movements of the protein's β-barrel towards the lower leaflet in DMPE. The study exhibited the use of molecular dynamics simulation in revealing the differential effect of membrane proteins and lipids on each other. In this study, POPE is potentially a more suitable model for future simulation of the S. typhi TolC protein.
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Poojari C, Strodel B. Stability of transmembrane amyloid β-peptide and membrane integrity tested by molecular modeling of site-specific Aβ42 mutations. PLoS One 2013; 8:e78399. [PMID: 24244308 PMCID: PMC3820573 DOI: 10.1371/journal.pone.0078399] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 09/11/2013] [Indexed: 11/20/2022] Open
Abstract
Interactions of the amyloid β-protein (Aβ) with neuronal cell membranes, leading to the disruption of membrane integrity, are considered to play a key role in the development of Alzheimer’s disease. Natural mutations in Aβ42, such as the Arctic mutation (E22G) have been shown to increase Aβ42 aggregation and neurotoxicity, leading to the early-onset of Alzheimer’s disease. A correlation between the propensity of Aβ42 to form protofibrils and its effect on neuronal dysfunction and degeneration has been established. Using rational mutagenesis of the Aβ42 peptide it was further revealed that the aggregation of different Aβ42 mutants in lipid membranes results in a variety of polymorphic aggregates in a mutation dependent manner. The mutant peptides also have a variable ability to disrupt bilayer integrity. To further test the connection between Aβ42 mutation and peptide–membrane interactions, we perform molecular dynamics simulations of membrane-inserted Aβ42 variants (wild-type and E22G, D23G, E22G/D23G, K16M/K28M and K16M/E22G/D23G/K28M mutants) as β-sheet monomers and tetramers. The effects of charged residues on transmembrane Aβ42 stability and membrane integrity are analyzed at atomistic level. We observe an increased stability for the E22G Aβ42 peptide and a decreased stability for D23G compared to wild-type Aβ42, while D23G has the largest membrane-disruptive effect. These results support the experimental observation that the altered toxicity arising from mutations in Aβ is not only a result of the altered aggregation propensity, but also originates from modified Aβ interactions with neuronal membranes.
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Affiliation(s)
- Chetan Poojari
- Institute of Complex Systems: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Birgit Strodel
- Institute of Complex Systems: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- * E-mail:
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8
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Petruk AA, Varriale S, Coscia MR, Mazzarella L, Merlino A, Oreste U. The structure of the CD3 ζζ transmembrane dimer in POPC and raft-like lipid bilayer: a molecular dynamics study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2637-45. [PMID: 23896554 DOI: 10.1016/j.bbamem.2013.07.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 07/05/2013] [Accepted: 07/16/2013] [Indexed: 12/15/2022]
Abstract
Plasma membrane lipids significantly affect assembly and activity of many signaling networks. The present work is aimed at analyzing, by molecular dynamics simulations, the structure and dynamics of the CD3 ζζ dimer in palmitoyl-oleoyl-phosphatidylcholine bilayer (POPC) and in POPC/cholesterol/sphingomyelin bilayer, which resembles the raft membrane microdomain supposed to be the site of the signal transducing machinery. Both POPC and raft-like environment produce significant alterations in structure and flexibility of the CD3 ζζ with respect to nuclear magnetic resonance (NMR) model: the dimer is more compact, its secondary structure is slightly less ordered, the arrangement of the Asp6 pair, which is important for binding to the Arg residue in the alpha chain of the T cell receptor (TCR), is stabilized by water molecules. Different interactions of charged residues with lipids at the lipid-cytoplasm boundary occur when the two environments are compared. Furthermore, in contrast to what is observed in POPC, in the raft-like environment correlated motions between transmembrane and cytoplasmic regions are observed. Altogether the data suggest that when the TCR complex resides in the raft domains, the CD3 ζζ dimer assumes a specific conformation probably necessary to the correct signal transduction.
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Affiliation(s)
- Ariel Alcides Petruk
- Instituto Superior de Investigaciones Biológicas (INSIBIO-CONICET), Chacabuco 461, S. M. de Tucumán, Tucumán T4000ILI, Argentina
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9
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Zhu S, Brown MF, Feller SE. Retinal conformation governs pKa of protonated Schiff base in rhodopsin activation. J Am Chem Soc 2013; 135:9391-8. [PMID: 23701524 PMCID: PMC5176254 DOI: 10.1021/ja4002986] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have explored the relationship between conformational energetics and the protonation state of the Schiff base in retinal, the covalently bound ligand responsible for activating the G protein-coupled receptor rhodopsin, using quantum chemical calculations. Guided by experimental structural determinations and large-scale molecular simulations on this system, we examined rotation about each bond in the retinal polyene chain, for both the protonated and deprotonated states that represent the dark and photoactivated states, respectively. Particular attention was paid to the torsional degrees of freedom that determine the shape of the molecule, and hence its interactions with the protein binding pocket. While most torsional degrees of freedom in retinal are characterized by large energetic barriers that minimize structural fluctuations under physiological temperatures, the C6-C7 dihedral defining the relative orientation of the β-ionone ring to the polyene chain has both modest barrier heights and a torsional energy surface that changes dramatically with protonation of the Schiff base. This surprising coupling between conformational degrees of freedom and protonation state is further quantified by calculations of the pKa as a function of the C6-C7 dihedral angle. Notably, pKa shifts of greater than two units arise from torsional fluctuations observed in molecular dynamics simulations of the full ligand-protein-membrane system. It follows that fluctuations in the protonation state of the Schiff base occur prior to forming the activated MII state. These new results shed light on important mechanistic aspects of retinal conformational changes that are involved in the activation of rhodopsin in the visual process.
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Affiliation(s)
- Shengshuang Zhu
- Department of Chemistry, Wabash College, Crawfordsville IN 47933
| | - Michael F. Brown
- Department of Chemistry and Biochemistry, University of Arizona, Tucson AZ 85721
- Department of Physics, University of Arizona, Tucson AZ 85721
| | - Scott E. Feller
- Department of Chemistry, Wabash College, Crawfordsville IN 47933
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10
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Tjörnhammar R, Edholm O. The shape and free energy of a lipid bilayer surrounding a membrane inclusion. Chem Phys Lipids 2013; 169:2-8. [DOI: 10.1016/j.chemphyslip.2012.12.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 12/21/2012] [Accepted: 12/24/2012] [Indexed: 11/30/2022]
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11
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Poojari C, Kukol A, Strodel B. How the amyloid-β peptide and membranes affect each other: An extensive simulation study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:327-39. [DOI: 10.1016/j.bbamem.2012.09.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 09/03/2012] [Accepted: 09/04/2012] [Indexed: 11/24/2022]
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12
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Computational Studies of Biomembrane Systems: Theoretical Considerations, Simulation Models, and Applications. FROM SINGLE MOLECULES TO NANOSCOPICALLY STRUCTURED MATERIALS 2013. [DOI: 10.1007/12_2013_258] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Abel S, Dupradeau FY, Marchi M. Molecular Dynamics Simulations of a Characteristic DPC Micelle in Water. J Chem Theory Comput 2012; 8:4610-23. [DOI: 10.1021/ct3003207] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Stéphane Abel
- Commissariat à l’Energie Atomique et aux Energies Alternatives, DSV/iBiTEC-S/SB2SM/LBMS, Saclay, France, CNRS UMR 8221, Saclay,
France
| | - François-Yves Dupradeau
- Laboratoire des glucides, UFR de Pharmacie & CNRS FRE 3517, Université de Picardie-Jules Verne, Amiens, France
| | - Massimo Marchi
- Commissariat à l’Energie Atomique et aux Energies Alternatives, DSV/iBiTEC-S/SB2SM/LBMS, Saclay, France, CNRS UMR 8221, Saclay,
France
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14
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Cordomí A, Perez JJ. Structural Rearrangements of Rhodopsin Subunits in a Dimer Complex: a Molecular Dynamics Simulation Study. J Biomol Struct Dyn 2012; 27:127-47. [DOI: 10.1080/07391102.2009.10507303] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Arnau Cordomí
- a Dept d'Enginyeria Química , Technical University of Catalonia (UPC), ETS d'Enginyeria Industrial , Av. Diagonal 647, 08028 , Barcelona , Spain
| | - Juan J. Perez
- a Dept d'Enginyeria Química , Technical University of Catalonia (UPC), ETS d'Enginyeria Industrial , Av. Diagonal 647, 08028 , Barcelona , Spain
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Xu J, Xu J, Chen H. Interpreting the structural mechanism of action for MT7 and human muscarinic acetylcholine receptor 1 complex by modeling protein–protein interaction. J Biomol Struct Dyn 2012; 30:30-44. [DOI: 10.1080/07391102.2012.674188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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16
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Kim T, Lee KI, Morris P, Pastor RW, Andersen OS, Im W. Influence of hydrophobic mismatch on structures and dynamics of gramicidin a and lipid bilayers. Biophys J 2012; 102:1551-60. [PMID: 22500755 DOI: 10.1016/j.bpj.2012.03.014] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 02/14/2012] [Accepted: 03/05/2012] [Indexed: 11/19/2022] Open
Abstract
Gramicidin A (gA) is a 15-amino-acid antibiotic peptide with an alternating L-D sequence, which forms (dimeric) bilayer-spanning, monovalent cation channels in biological membranes and synthetic bilayers. We performed molecular dynamics simulations of gA dimers and monomers in all-atom, explicit dilauroylphosphatidylcholine (DLPC), dimyristoylphosphatidylcholine (DMPC), dioleoylphosphatidylcholine (DOPC), and 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayers. The variation in acyl chain length among these different phospholipids provides a way to alter gA-bilayer interactions by varying the bilayer hydrophobic thickness, and to determine the influence of hydrophobic mismatch on the structure and dynamics of both gA channels (and monomeric subunits) and the host bilayers. The simulations show that the channel structure varied little with changes in hydrophobic mismatch, and that the lipid bilayer adapts to the bilayer-spanning channel to minimize the exposure of hydrophobic residues. The bilayer thickness, however, did not vary monotonically as a function of radial distance from the channel. In all simulations, there was an initial decrease in thickness within 4-5 Å from the channel, which was followed by an increase in DOPC and POPC or a further decrease in DLPC and DMPC bilayers. The bilayer thickness varied little in the monomer simulations-except one of three independent simulations for DMPC and all three DLPC simulations, where the bilayer thinned to allow a single subunit to form a bilayer-spanning water-permeable pore. The radial dependence of local lipid area and bilayer compressibility is also nonmonotonic in the first shell around gA dimers due to gA-phospholipid interactions and the hydrophobic mismatch. Order parameters, acyl chain dynamics, and diffusion constants also differ between the lipids in the first shell and the bulk. The lipid behaviors in the first shell around gA dimers are more complex than predicted from a simple mismatch model, which has implications for understanding the energetics of membrane protein-lipid interactions.
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Affiliation(s)
- Taehoon Kim
- Department of Molecular Biosciences and Center for Bioinformatics, The University of Kansas, Lawrence, Kansas, USA
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Molecular modeling of the M3 acetylcholine muscarinic receptor and its binding site. J Biomed Biotechnol 2012; 2012:789741. [PMID: 22500107 PMCID: PMC3303834 DOI: 10.1155/2012/789741] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 11/08/2011] [Indexed: 11/21/2022] Open
Abstract
The present study reports the results of a combined computational and site mutagenesis study designed to provide new insights into the orthosteric binding site of the human M3 muscarinic acetylcholine receptor. For this purpose a three-dimensional structure of the receptor at atomic resolution was built by homology modeling, using the crystallographic structure of bovine rhodopsin as a template. Then, the antagonist N-methylscopolamine was docked in the model and subsequently embedded in a lipid bilayer for its refinement using molecular dynamics simulations. Two different lipid bilayer compositions were studied: one component palmitoyl-oleyl phosphatidylcholine (POPC) and two-component palmitoyl-oleyl phosphatidylcholine/palmitoyl-oleyl phosphatidylserine (POPC-POPS). Analysis of the results suggested that residues F222 and T235 may contribute to the ligand-receptor recognition. Accordingly, alanine mutants at positions 222 and 235 were constructed, expressed, and their binding properties determined. The results confirmed the role of these residues in modulating the binding affinity of the ligand.
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18
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Cordomí A, Caltabiano G, Pardo L. Membrane Protein Simulations Using AMBER Force Field and Berger Lipid Parameters. J Chem Theory Comput 2012; 8:948-58. [PMID: 26593357 DOI: 10.1021/ct200491c] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
AMBER force fields are among the most commonly used in molecular dynamics (MD) simulations of proteins. Unfortunately, they lack a specific set of lipid parameters, thus limiting its use in membrane protein simulations. In order to overcome this limitation we assessed whether the widely used united-atom lipid parameters described by Berger and co-workers could be used in conjunction with AMBER force fields in simulations of membrane proteins. Thus, free energies of solvation in water and in cyclohexane, and free energies of water to cyclohexane transfer, were computed by thermodynamic integration procedures for neutral amino acid side-chains employing AMBER99, AMBER03, and OPLS-AA amino acid force fields. In addition, MD simulations of three membrane proteins in a POPC lipid bilayer, the β2 adrenergic G protein-coupled receptor, Aquaporin-1, and the outer membrane protein Omp32, were performed with the aim of comparing the AMBER99SB/Berger combination of force fields with the OPLS-AA/Berger combination. We have shown that AMBER99SB and Berger force fields are compatible, they provide reliable free energy estimations relative to experimental values, and their combination properly describes both membrane and protein structural properties. We then suggest that the AMBER99SB/Berger combination is a reliable choice for the simulation of membrane proteins, which links the easiness of ligand parametrization and the ability to reproduce secondary structure of AMBER99SB force field with the largely validated Berger lipid parameters.
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Affiliation(s)
- Arnau Cordomí
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Gianluigi Caltabiano
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
| | - Leonardo Pardo
- Laboratori de Medicina Computacional, Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona , 08193 Bellaterra, Spain
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Merlino A, Vitiello G, Grimaldi M, Sica F, Busi E, Basosi R, D’Ursi AM, Fragneto G, Paduano L, D’Errico G. Destabilization of Lipid Membranes by a Peptide Derived from Glycoprotein gp36 of Feline Immunodeficiency Virus: A Combined Molecular Dynamics/Experimental Study. J Phys Chem B 2011; 116:401-12. [DOI: 10.1021/jp204781a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Antonello Merlino
- Department of Chemistry, University of Naples ‘‘Federico II’’, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
- Istituto di Biostrutture e Bioimmagini, CNR, Naples, Italy
| | - Giuseppe Vitiello
- Department of Chemistry, University of Naples ‘‘Federico II’’, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
- CSGI (Consorzio per lo Sviluppo dei Sistemi a Grande Interfase), Florence, Italy
| | - Manuela Grimaldi
- Department of Pharmaceutical Science, University of Salerno, Fisciano, Italy
| | - Filomena Sica
- Department of Chemistry, University of Naples ‘‘Federico II’’, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
- Istituto di Biostrutture e Bioimmagini, CNR, Naples, Italy
| | - Elena Busi
- CSGI (Consorzio per lo Sviluppo dei Sistemi a Grande Interfase), Florence, Italy
- Department of Chemistry, University of Siena, Siena, Italy
| | - Riccardo Basosi
- CSGI (Consorzio per lo Sviluppo dei Sistemi a Grande Interfase), Florence, Italy
- Department of Chemistry, University of Siena, Siena, Italy
| | - Anna Maria D’Ursi
- Department of Pharmaceutical Science, University of Salerno, Fisciano, Italy
| | | | - Luigi Paduano
- Department of Chemistry, University of Naples ‘‘Federico II’’, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
- CSGI (Consorzio per lo Sviluppo dei Sistemi a Grande Interfase), Florence, Italy
| | - Gerardino D’Errico
- Department of Chemistry, University of Naples ‘‘Federico II’’, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
- CSGI (Consorzio per lo Sviluppo dei Sistemi a Grande Interfase), Florence, Italy
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20
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Fanelli F, De Benedetti PG. Update 1 of: computational modeling approaches to structure-function analysis of G protein-coupled receptors. Chem Rev 2011; 111:PR438-535. [PMID: 22165845 DOI: 10.1021/cr100437t] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Francesca Fanelli
- Dulbecco Telethon Institute, University of Modena and Reggio Emilia, via Campi 183, 41125 Modena, Italy.
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21
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Cerezo J, Zúñiga J, Bastida A, Requena A, Cerón-Carrasco JP. Atomistic Molecular Dynamics Simulations of the Interactions of Oleic and 2-Hydroxyoleic Acids with Phosphatidylcholine Bilayers. J Phys Chem B 2011; 115:11727-38. [DOI: 10.1021/jp203498x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Javier Cerezo
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - José Zúñiga
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - Adolfo Bastida
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - Alberto Requena
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - José Pedro Cerón-Carrasco
- CEISAM, UMR CNRS 6230, BP 92208, Université de Nantes, 2, rue de la Houssiniére, 44322 Nantes Cedex 3, France
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22
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Dai W, You Z, Zhou H, Zhang J, Hu Y. Structure–function relationships of the human bitter taste receptor hTAS2R1: insights from molecular modeling studies. J Recept Signal Transduct Res 2011; 31:229-40. [DOI: 10.3109/10799893.2011.578141] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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23
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Manna M, Mukhopadhyay C. Molecular dynamics simulations of the interactions of kinin peptides with an anionic POPG bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:3713-3722. [PMID: 21355573 DOI: 10.1021/la104046z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have performed molecular dynamics simulations of peptide hormone bradykinin (BK) and its fragment des-Arg9-BK in the presence of an anionic lipid bilayer, with an aim toward delineating the mechanism of action related to their bioactivity. Starting from the initial aqueous environment, both of the peptides are quickly adsorbed and stabilized on the cell surface. Whereas BK exhibits a stronger interaction with the membrane and prefers to stay on the interface, des-Arg9-BK, with the loss of C-terminal Arg, penetrates further. The heterogeneous lipid-water interface induces β-turn-like structure in the otherwise inherently flexible peptides. In the membrane-bound state, we observed C-terminal β-turn formation in BK, whereas for des-Arg9-BK, with the deletion of Arg9, turn formation occurred in the middle of the peptide. The basic Arg residues anchor the peptide to the bilayer by strong electrostatic interactions with charged lipid headgroups. Simulations with different starting orientations of the peptides with respect to the bilayer surface lead to the same observations, namely, the relative positioning of the peptides on the membrane surface, deeper penetration of the des-Arg9-BK, and the formation of turn structures. The lipid headgroups adjacent to the bound peptides become substantially tilted, causing bilayer thinning near the peptide contact region and increase the degree of disorder in nearby lipids. Again, because of hydrogen bonding with the peptide, the neighboring lipid's polar heads exhibit considerably reduced flexibility. Corroborating findings from earlier experiments, our results provide important information about how the lipid environment promotes peptide orientation/conformation and how the peptide adapts to the environment.
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Affiliation(s)
- Moutusi Manna
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata-700 009, India
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24
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Abstract
Membrane proteins play a key role in energy conversion, transport, signal recognition, transduction, and other fundamental biological processes. Despite considerable progress in experimental techniques, the determination of structure and dynamics of membrane proteins still represents a great challenge. Computer simulation methods are becoming an increasingly important tool not only in the interpretation of experiments but also in the prediction of membrane protein dynamics. In the present review, we give a brief introduction to molecular modeling techniques currently used to explore protein dynamics on time scales ranging from femtoseconds to microseconds. We then describe a few recent example applications of these techniques to membrane proteins. In conclusion, we also discuss some of the newest developments in simulation methodology that have the potential to further extend the time scale accessible to explore (membrane) protein dynamics.
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25
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Bortolato A, Mobarec JC, Provasi D, Filizola M. Progress in elucidating the structural and dynamic character of G Protein-Coupled Receptor oligomers for use in drug discovery. Curr Pharm Des 2010; 15:4017-25. [PMID: 20028319 DOI: 10.2174/138161209789824768] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
G Protein-Coupled Receptors (GPCRs) are the most targeted group of proteins for the development of therapeutic drugs. Until the last decade, structural information about this family of membrane proteins was relatively scarce, and their mechanisms of ligand binding and signal transduction were modeled on the assumption that GPCRs existed and functioned as monomeric entities. New crystal structures of native and engineered GPCRs, together with important biochemical and biophysical data that reveal structural details of the activation mechanism(s) of this receptor family, provide a valuable framework to improve dynamic molecular models of GPCRs with the ultimate goal of elucidating their allostery and functional selectivity. Since the dynamic movements of single GPCR protomers are likely to be affected by the presence of neighboring interacting subunits, oligomeric arrangements should be taken into account to improve the predictive ability of computer-assisted structural models of GPCRs for effective use in drug design.
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Affiliation(s)
- A Bortolato
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, NY 10029-6574, USA
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26
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Cordomí A, Prades J, Frau J, Vögler O, Funari SS, Perez JJ, Escribá PV, Barceló F. Interactions of fatty acids with phosphatidylethanolamine membranes: X-ray diffraction and molecular dynamics studies. J Lipid Res 2009; 51:1113-24. [PMID: 19965616 DOI: 10.1194/jlr.m003012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An experimental and theoretical study on 1,2-dielaidoyl-sn-glycero-3-phosphoethanolamine (DEPE) membranes containing fatty acids (FAs) was performed by means of X-ray diffraction analysis and molecular dynamics (MD) simulations. The study was aimed at understanding the interactions of several structurally related FAs with biomembranes, which is necessary for further rational lipid drug design in membrane-lipid therapy. The main effect of FAs was to promote the formation of a H(II) phase, despite a stabilization of the coexisting L(alpha) + H(II) phases. Derivatives of OA exhibited a specific density profile in the direction perpendicular to the bilayer that reflects differences in the relative localization of the carboxylate group within the polar region of the membrane as well as in the degree of membrane penetration of the FA acyl chain. Hydroxyl and methyl substituents at carbon-2 in the FA acyl chain were identified as effective modulators of the position of carboxylate group in the lipid bilayer. Our data highlight the specific potential of each FA in modulating the membrane structure properties.
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Affiliation(s)
- Arnau Cordomí
- Department d'Enginyeria Química, Technical University of Catalonia, Barcelona, Spain
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27
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Zobnina V, Roterman I. Application of the fuzzy-oil-drop model to membrane protein simulation. Proteins 2009; 77:378-94. [PMID: 19455711 DOI: 10.1002/prot.22443] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The analysis of structural properties and biological activity of membrane proteins requires long lasting simulation of molecular dynamics. The large number of atoms present in protein molecule, membrane (phospholipids), and water environment makes the simulation of large scale. The implementation of simplified model representing the natural environment for membrane proteins is presented and compared with the vacuum simulation and simulation in the presence of water molecules and membrane phospholipids presented explicite. The comparative structural analysis and computational times for these three models makes the simplified model promising.
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Affiliation(s)
- Veronica Zobnina
- Department of Bioinformatics and Telemedicine, Collegium Medicum-Jagiellonian University, Krakow, Poland
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28
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Manna M, Mukhopadhyay C. Cause and effect of melittin-induced pore formation: a computational approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:12235-12242. [PMID: 19754202 DOI: 10.1021/la902660q] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Melittin embedded in a palmitoyl oleyl phosphatidylcholine bilayer at a high peptide/lipid ratio (1:30) was simulated in the presence of explicit water and ions. The simulation results indicate the incipience of an ion-permeable water pore through collective membrane perturbation by bound peptides. The positively charged residues of melittin not only act as "anchors" but also disrupt the membrane, leading to cell lysis. A detailed analysis of the lipid tail order parameter profile depicts localized membrane perturbation. The lipids in the vicinity of the aqueous cavity adopt a tilted conformation, which allows local bilayer thinning. The prepore thus formed can be considered as the melittin-induced structural defects in the bilayer membrane. Because of the strong cationic nature, the melittin-induced prepore exhibits selectivity toward anions over cations. As Cl(-) ions entered into the prepore, they are electrostatically entrapped by positively charged residues located at its wall. The confined motion of the Cl(-) ions in the membrane interior is obvious from calculated diffusion coefficients. Moreover, reorientation of the local lipids occurs in such a way that few lipid heads along with peptide helices can line the surface of the penetrating aqueous phase. The flipping of lipids argued in favor of melittin-induced toroidal pore over a barrel-stave mechanism. Thus, our result provides atomistic level details of the mechanism of membrane disruption by antimicrobial peptide melittin.
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Affiliation(s)
- Moutusi Manna
- Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata-700 009, India
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29
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Schmid F. Toy amphiphiles on the computer: What can we learn from generic models? Macromol Rapid Commun 2009; 30:741-51. [DOI: 10.1002/marc.200800750] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Accepted: 01/20/2009] [Indexed: 11/08/2022]
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30
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Toledo D, Cordomí A, Proietti MG, Benfatto M, del Valle LJ, Pérez JJ, Garriga P, Sepulcre F. Structural Characterization of a Zinc High-affinity Binding Site in Rhodopsin. Photochem Photobiol 2009; 85:479-84. [DOI: 10.1111/j.1751-1097.2008.00529.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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31
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West B, Brown FLH, Schmid F. Membrane-protein interactions in a generic coarse-grained model for lipid bilayers. Biophys J 2009; 96:101-15. [PMID: 18835907 PMCID: PMC2710048 DOI: 10.1529/biophysj.108.138677] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 09/04/2008] [Indexed: 11/18/2022] Open
Abstract
We study membrane-protein interactions and membrane-mediated protein-protein interactions by Monte Carlo simulations of a generic coarse-grained model for lipid bilayers with cylindrical hydrophobic inclusions. The strength of the hydrophobic force and the hydrophobic thickness of the proteins are systematically varied. The results are compared with analytical predictions of two popular analytical theories: The Landau-de Gennes theory and the elastic theory. The elastic theory provides an excellent description of the fluctuation spectra of pure membranes and successfully reproduces the deformation profiles of membranes around single proteins. However, its prediction for the potential of mean force between proteins is not compatible with the simulation data for large distances. The simulations show that the lipid-mediated interactions are governed by five competing factors: direct interactions; lipid-induced depletion interactions; lipid bridging; lipid packing; and a smooth long-range contribution. The mechanisms leading to hydrophobic mismatch interactions are critically analyzed.
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Affiliation(s)
- Beate West
- Fakultät für Physik, Universität Bielefeld, Bielefeld, Germany.
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32
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Tikhonova IG, Best RB, Engel S, Gershengorn MC, Hummer G, Costanzi S. Atomistic insights into rhodopsin activation from a dynamic model. J Am Chem Soc 2008; 130:10141-9. [PMID: 18620390 DOI: 10.1021/ja0765520] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rhodopsin, the light sensitive receptor responsible for blue-green vision, serves as a prototypical G protein-coupled receptor (GPCR). Upon light absorption, it undergoes a series of conformational changes that lead to the active form, metarhodopsin II (META II), initiating a signaling cascade through binding to the G protein transducin (G(t)). Here, we first develop a structural model of META II by applying experimental distance restraints to the structure of lumi-rhodopsin (LUMI), an earlier intermediate. The restraints are imposed by using a combination of biased molecular dynamics simulations and perturbations to an elastic network model. We characterize the motions of the transmembrane helices in the LUMI-to-META II transition and the rearrangement of interhelical hydrogen bonds. We then simulate rhodopsin activation in a dynamic model to study the path leading from LUMI to our META II model for wild-type rhodopsin and a series of mutants. The simulations show a strong correlation between the transition dynamics and the pharmacological phenotypes of the mutants. These results help identify the molecular mechanisms of activation in both wild type and mutant rhodopsin. While static models can provide insights into the mechanisms of ligand recognition and predict ligand affinity, a dynamic model of activation could be applicable to study the pharmacology of other GPCRs and their ligands, offering a key to predictions of basal activity and ligand efficacy.
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Affiliation(s)
- Irina G Tikhonova
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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33
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Cordomí A, Ramon E, Garriga P, Perez JJ. Molecular Dynamics Simulations of Rhodopsin Point Mutants at the Cytoplasmic Side of Helices 3 and 6. J Biomol Struct Dyn 2008; 25:573-87. [DOI: 10.1080/07391102.2008.10507204] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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34
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Mobarec JC, Filizola M. Advances in the Development and Application of Computational Methodologies for Structural Modeling of G-Protein Coupled Receptors. Expert Opin Drug Discov 2008; 3:343-355. [PMID: 19672320 DOI: 10.1517/17460441.3.3.343] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND: Despite the large amount of experimental data accumulated in the past decade on G-protein coupled receptor (GPCR) structure and function, understanding of the molecular mechanisms underlying GPCR signaling is still far from being complete, thus impairing the design of effective and selective pharmaceuticals. OBJECTIVE: Understanding of GPCR function has been challenged even further by more recent experimental evidence that several of these receptors are organized in the cell membrane as homo- or hetero-oligomers, and that they may exhibit unique pharmacological properties. Given the complexity of these new signaling systems, researcher's efforts are turning increasingly to molecular modeling, bioinformatics and computational simulations for mechanistic insights of GPCR functional plasticity. METHODS: We review here current advances in the development and application of computational approaches to improve prediction of GPCR structure and dynamics, thus enhancing current understanding of GPCR signaling. RESULTS/CONCLUSIONS: Models resulting from use of these computational approaches further supported by experiments are expected to help elucidate the complex allosterism that propagates through GPCR complexes, ultimately aiming at successful structure-based rational drug design.
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Affiliation(s)
- Juan Carlos Mobarec
- Department of Structural and Chemical Biology, Mount Sinai School of Medicine, Icahn Medical Institute Building, 1425 Madison Avenue, Box 1677, New York, NY 10029-6574, Tel: 212-241-8634
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35
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Cordomí A, Edholm O, Perez JJ. Effect of ions on a dipalmitoyl phosphatidylcholine bilayer. a molecular dynamics simulation study. J Phys Chem B 2008; 112:1397-408. [PMID: 18193856 DOI: 10.1021/jp073897w] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effect of physiological concentrations of different chlorides on the structure of a dipalmitoyl phosphatidylcholine (DPPC) bilayer has been investigated through atomistic molecular dynamics simulations. These calculations provide support to the concept that Li+, Na+, Ca2+, Mg2+, Sr2+, Ba2+, and Ac3+, but not K+, bind to the lipid-head oxygens. Ion binding exhibits an influence on lipid order, area per lipid, orientation of the lipid head dipole, the charge distribution in the system, and therefore the electrostatic potential across the head-group region of the bilayer. These structural effects are sensitive to the specific characteristics of each cation, i.e., radius, charge, and coordination properties. These results provide evidence aimed at shedding some light into the apparent contradictions among different studies reported recently regarding the ordering effect of ions on zwitterionic phosphatidylcholine lipid bilayers.
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Affiliation(s)
- Arnau Cordomí
- Department of Chemical Engineering, Technical University of Catalonia (UPC), Av. Diagonal 647, 08028 Barcelona, Spain
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36
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Jójárt B, Balogh B, Márki A. Modeling the human oxytocin receptor for drug discovery efforts. Expert Opin Drug Discov 2007; 2:1579-90. [PMID: 23488902 DOI: 10.1517/17460441.2.12.1579] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The oxytocin receptor belongs to class A receptors within the great family of G protein-coupled receptors. The endogenous ligand oxytocin is a nonapeptide hormone that induces the uterine contractions at parturition and is used to induce the labor. The peptide oxytocin and, even more, its non-peptide antagonist, could be valuable tools in tocolysis. The knowledge of the three-dimensional structure of the oxytocin receptor and the determination of the main interaction points between the receptor and the ligands may help to develop selective oxytocin agonists and antagonist. This review summarizes the knowledge about the mapping of the binding domain of the oxytocin receptor and the efforts in the field of molecular modeling studies related to oxytocin receptor-ligand interactions.
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Affiliation(s)
- Balázs Jójárt
- University of Szeged, Department of Chemistry and Chemical Informatics, Faculty of Education, Boldogasszony sgt. 6. 6725 Szeged, Hungary +36 62 544 720 ; +36 62 420 953 ;
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