1
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Pawar AB, Sengupta D. Role of Cholesterol in Transmembrane Dimerization of the ErbB2 Growth Factor Receptor. J Membr Biol 2021; 254:301-310. [PMID: 33506276 DOI: 10.1007/s00232-021-00168-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/05/2021] [Indexed: 11/28/2022]
Abstract
The association of ErbB2 growth factor receptors is critical for cell growth and potentiates tumor proliferation in several cancer types. An important aspect in ErbB2 association is the role of lipids such as cholesterol, especially since their metabolism is often reprogrammed in cancer cells. Here, we have coupled metadynamics with coarse-grain simulations to identify cholesterol effects in the transmembrane dimerization of ErbB2 receptors. Overall, cholesterol interactions are observed with the receptor that directly tunes the association energetics. Several dimer conformations are identified both in the presence and absence of cholesterol, although the dimer regime appears to be more favorable in the presence of cholesterol. We observe an overall modulation of the underlying energy profile and the symmetric active and inactive conformational states are not distinguished in the presence of cholesterol. We show that cholesterol binds to the receptor transmembrane domain at a site (CRAC motif) that overlaps with the dimer interface (SmXXXSm motif). The competition between the transmembrane interactions and cholesterol interactions decides the final conformational landscape. Our work is an important step toward characterizing cholesterol effects in ErbB2 membrane receptor function.
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Affiliation(s)
- Aiswarya B Pawar
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Durba Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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2
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Kukol A. Meet Our Editorial Board Member. Protein Pept Lett 2019. [DOI: 10.2174/092986652602190220155059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Andreas Kukol
- Department of Biological and Environmental Sciences School of Life and Medical Sciences University of Hertfordshire Hatfield AL10 9AB, United Kingdom
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3
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Leonard AN, Wang E, Monje-Galvan V, Klauda JB. Developing and Testing of Lipid Force Fields with Applications to Modeling Cellular Membranes. Chem Rev 2019; 119:6227-6269. [DOI: 10.1021/acs.chemrev.8b00384] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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4
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Kar P, Gopal SM, Cheng YM, Panahi A, Feig M. Transferring the PRIMO Coarse-Grained Force Field to the Membrane Environment: Simulations of Membrane Proteins and Helix-Helix Association. J Chem Theory Comput 2014; 10:3459-3472. [PMID: 25136271 PMCID: PMC4132866 DOI: 10.1021/ct500443v] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Indexed: 12/03/2022]
Abstract
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An
extension of the recently developed PRIMO coarse-grained force
field to membrane environments, PRIMO-M, is described. The membrane
environment is modeled with the heterogeneous dielectric generalized
Born (HDGB) methodology that simply replaces the standard generalized
Born model in PRIMO without further parametrization. The resulting
model was validated by comparing amino acid insertion free energy
profiles and application in molecular dynamics simulations of membrane
proteins and membrane-interacting peptides. Membrane proteins with
148–661 amino acids show stable root-mean-squared-deviations
(RMSD) between 2 and 4 Å for most systems. Transmembrane helical
peptides maintain helical shape and exhibit tilt angles in good agreement
with experimental or other simulation data. The association of two
glycophorin A (GpA) helices was simulated using replica exchange molecular
dynamics simulations yielding the correct dimer structure with a crossing
angle in agreement with previous studies. Finally, conformational
sampling of the influenza fusion peptide also generates structures
in agreement with previous studies. Overall, these findings suggest
that PRIMO-M can be used to study membrane bound peptides and proteins
and validates the transferable nature of the PRIMO coarse-grained
force field.
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Affiliation(s)
- Parimal Kar
- Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
| | - Srinivasa Murthy Gopal
- Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
| | - Yi-Ming Cheng
- Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
| | - Afra Panahi
- Departments of Chemistry and Biophysics, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Michael Feig
- Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States ; Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University , East Lansing, Michigan 48824, United States
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5
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Brooks AJ, Dai W, O'Mara ML, Abankwa D, Chhabra Y, Pelekanos RA, Gardon O, Tunny KA, Blucher KM, Morton CJ, Parker MW, Sierecki E, Gambin Y, Gomez GA, Alexandrov K, Wilson IA, Doxastakis M, Mark AE, Waters MJ. Mechanism of activation of protein kinase JAK2 by the growth hormone receptor. Science 2014; 344:1249783. [PMID: 24833397 DOI: 10.1126/science.1249783] [Citation(s) in RCA: 280] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Signaling from JAK (Janus kinase) protein kinases to STAT (signal transducers and activators of transcription) transcription factors is key to many aspects of biology and medicine, yet the mechanism by which cytokine receptors initiate signaling is enigmatic. We present a complete mechanistic model for activation of receptor-bound JAK2, based on an archetypal cytokine receptor, the growth hormone receptor. For this, we used fluorescence resonance energy transfer to monitor positioning of the JAK2 binding motif in the receptor dimer, substitution of the receptor extracellular domains with Jun zippers to control the position of its transmembrane (TM) helices, atomistic modeling of TM helix movements, and docking of the crystal structures of the JAK2 kinase and its inhibitory pseudokinase domain with an opposing kinase-pseudokinase domain pair. Activation of the receptor dimer induced a separation of its JAK2 binding motifs, driven by a ligand-induced transition from a parallel TM helix pair to a left-handed crossover arrangement. This separation leads to removal of the pseudokinase domain from the kinase domain of the partner JAK2 and pairing of the two kinase domains, facilitating trans-activation. This model may well generalize to other class I cytokine receptors.
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Affiliation(s)
- Andrew J Brooks
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
| | - Wei Dai
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Megan L O'Mara
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Daniel Abankwa
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yash Chhabra
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Rebecca A Pelekanos
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Olivier Gardon
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kathryn A Tunny
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kristopher M Blucher
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Craig J Morton
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Michael W Parker
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia. Department of Biochemistry and Molecular Biology and Bio21 Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Emma Sierecki
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yann Gambin
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Guillermo A Gomez
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kirill Alexandrov
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Ian A Wilson
- Scripps Research Institute, La Jolla, CA 92037, USA
| | - Manolis Doxastakis
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Alan E Mark
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia. The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Michael J Waters
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
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6
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Li LH, Fischer WB. Correlation of biological activity with computationally derived structural features from transmembrane hetero-dimers of HIV-1 Vpu with host factors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:1104-12. [PMID: 24036078 DOI: 10.1016/j.bbamem.2013.07.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/26/2013] [Accepted: 07/31/2013] [Indexed: 01/29/2023]
Abstract
Vpu is an 81 amino acid type I integral membrane protein encoded by human immunodeficiency virus type 1 (HIV-1). It is identified to support viral release by potentially forming ion and substrate conducting channels and by modulating the function of host factors. The focus is on the interaction of the transmembrane domains of Vpu with those of host factors using a combination of molecular dynamics simulations and docking approach. Binding poses and adopted tilt angles of the dimers are analyzed and correlated with experimentally derived activity data from literature. Vpu activity is driven by dimerization with the host protein via its alanine rim Ala-8/11/15/19. Tight binding is shown by an almost parallel alignment of the helices in the dimers. Less parallel alignment is proposed to correlate with lower activity. This article is part of a Special Issue entitled: Viral Membrane Proteins - Channels for Cellular Networking.
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Affiliation(s)
- Li-Hua Li
- Institute of Biophotonics, School of Biomedical Science and Engineering, and Biophotonics & Molecular Imaging Research Center (BMIRC), National Yang-Ming University, Taipei 112, Taiwan
| | - Wolfgang B Fischer
- Institute of Biophotonics, School of Biomedical Science and Engineering, and Biophotonics & Molecular Imaging Research Center (BMIRC), National Yang-Ming University, Taipei 112, Taiwan.
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7
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Beevers AJ, Nash A, Salazar-Cancino M, Scott DJ, Notman R, Dixon AM. Effects of the Oncogenic V664E Mutation on Membrane Insertion, Structure, and Sequence-Dependent Interactions of the Neu Transmembrane Domain in Micelles and Model Membranes: An Integrated Biophysical and Simulation Study. Biochemistry 2012; 51:2558-68. [DOI: 10.1021/bi201269w] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - David J. Scott
- Department of Biosciences, University of Nottingham, Nottingham, U.K
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8
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Wan CK, Han W, Wu YD. Parameterization of PACE Force Field for Membrane Environment and Simulation of Helical Peptides and Helix–Helix Association. J Chem Theory Comput 2011; 8:300-13. [DOI: 10.1021/ct2004275] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Cheuk-Kin Wan
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Wei Han
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yun-Dong Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- School of Chemical Biology and Biotechnology, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
- College of Chemistry, Peking University, Beijing, 100871, China
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9
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Pandey PR, Roy S. Headgroup mediated water insertion into the DPPC bilayer: a molecular dynamics study. J Phys Chem B 2011; 115:3155-63. [PMID: 21384811 DOI: 10.1021/jp1090203] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular dynamics simulation was performed on the 1,2-dipalmitoyl-sn-phosphocholine (DPPC) bilayer-water system using the GROMOS96 53a6 united atom force field. The transferability of force field was tested by reproducing the area per lipid within 3% accuracy from the experimental value. The simulation shows that water can penetrate much deeper inside the bilayer almost up to the starting point of the aliphatic chain. There is significant evidence from experiments that water goes deep in the DPPC bilayer, but it has not been reported from theoretical work. The mechanism of insertion of water deep inside the lipid bilayer is still not clear. In this report, for the first time, the mechanism of water insertion deep into the bilayer has been proposed. Water transport occurs by the headgroup and its first solvation shell. The trimethyl ammonium (NMe(3)) group (headgroup of DPPC) has two stable conformations at the bilayer-water interface, one outside the bilayer and another inside it. The NMe(3) group has a large clustering of water around it and takes the water molecules inside the bilayer with it during its entry into the bilayer. The water molecules penetrate into the bilayer with the help of the NMe(3) group present at the headgroup of DPPC and eventually form hydrogen bonds with carbonyl oxygen present deep inside the bilayer. Structural characteristics at the bilayer-water interface region are also reported.
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10
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Beevers AJ, Damianoglou A, Oates J, Rodger A, Dixon AM. Sequence-Dependent Oligomerization of the Neu Transmembrane Domain Suggests Inhibition of “Conformational Switching” by an Oncogenic Mutant. Biochemistry 2010; 49:2811-20. [DOI: 10.1021/bi902087v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew J. Beevers
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | | | - Joanne Oates
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Alison Rodger
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Ann M. Dixon
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
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11
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Chugunov AO, Efremov RG. [Prediction of the spatial structure of proteins: emphasis on membrane targets]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 35:744-60. [PMID: 20208575 DOI: 10.1134/s106816200906003x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Knowledge of the spatial structure of proteins is a prerequisite for both awareness of their functional mechanisms and the framework for rational drug discovery and design. Meanwhile, direct structural determination is often hampered or impractical due to the complexity, expensiveness, and limited capabilities of experimental techniques. These issues are especially pronounced for integral membrane proteins. On numerous occasions, the theoretical prediction of protein structures may facilitate the process by exploiting physical or empirical principles. This paper surveys modern techniques for the prediction of the spatial structure of proteins using computer algorithms, and the main emphasis is placed on the most "complex" targets - membrane proteins (MPs). The first part of the review describes de novo methods based on empirical physical principles; in the second part, a comparative modeling philosophy, which accounts for the structure of related proteins, is described. Special focus is made regarding pharmacologically relevant classes of G-coupled receptors, receptor tyrosine ki-nases, and other MPs. Algorithms for the assessment of the models quality and potential fields of application of computer models are discussed.
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12
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Langosch D, Arkin IT. Interaction and conformational dynamics of membrane-spanning protein helices. Protein Sci 2009; 18:1343-58. [PMID: 19530249 PMCID: PMC2775205 DOI: 10.1002/pro.154] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 04/19/2009] [Accepted: 04/20/2009] [Indexed: 12/23/2022]
Abstract
Within 1 or 2 decades, the reputation of membrane-spanning alpha-helices has changed dramatically. Once mostly regarded as dull membrane anchors, transmembrane domains are now recognized as major instigators of protein-protein interaction. These interactions may be of exquisite specificity in mediating assembly of stable membrane protein complexes from cognate subunits. Further, they can be reversible and regulatable by external factors to allow for dynamic changes of protein conformation in biological function. Finally, these helices are increasingly regarded as dynamic domains. These domains can move relative to each other in different functional protein conformations. In addition, small-scale backbone fluctuations may affect their function and their impact on surrounding lipid shells. Elucidating the ways by which these intricate structural features are encoded by the amino acid sequences will be a fascinating subject of research for years to come.
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Affiliation(s)
- Dieter Langosch
- Lehrstuhl Chemie der Biopolymere, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany.
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13
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Kukol A. Lipid Models for United-Atom Molecular Dynamics Simulations of Proteins. J Chem Theory Comput 2009; 5:615-26. [PMID: 26610227 DOI: 10.1021/ct8003468] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
United-atom force fields for molecular dynamics (MD) simulations provide a higher computational efficiency, especially in lipid membrane simulations, with little sacrifice in accuracy, when compared to all-atom force fields. Excellent united-atom lipid models are available, but in combination with depreciated protein force fields. In this work, a united-atom model of the lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine has been built with standard parameters of the force field GROMOS96 53a6 that reproduces the experimental area per lipid of a lipid bilayer within 3% accuracy to a value of 0.623 ± 0.011 nm(2) without the assumption of a constant surface area or the inclusion of surface pressure. In addition, the lateral self-diffusion constant and deuterium order parameters of the acyl chains are in agreement with experimental data. Furthermore, models for 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) result in areas per lipid of 0.625 nm(2) (DMPC), 0.693 nm(2) (POPC), and 0.700 nm(2) (POPG) from 40 ns MD simulations. Experimental lateral self-diffusion coefficients are reproduced satisfactorily by the simulation. The lipid models can form the basis for molecular dynamics simulations of membrane proteins with current and future versions of united-atom protein force fields.
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Affiliation(s)
- Andreas Kukol
- School of Life Sciences, University of Hertfordshire, Hatfield AL10 9AB, United Kingdom
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14
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Beevers AJ, Kukol A. Transmembrane protein models based on high-throughput molecular dynamics simulations with experimental constraints. Methods Mol Biol 2008; 443:213-227. [PMID: 18446290 DOI: 10.1007/978-1-59745-177-2_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Elucidating the structure of transmembrane proteins domains with high-resolution methods is a difficult and sometimes impossible task. Here, we explain the method of combining a limited amount of experimental data with automated high-throughput molecular dynamics (MD) simulations of alpha-helical transmembrane bundles in an explicit lipid bilayer/water environment. The procedure uses a systematic conformational search of the helix rotation with experimentally constrained MDs simulations. The experimentally determined helix tilt and rotational angle of a labeled residue with site-specific infrared dichroism allows us to select a unique high-resolution model from a number of possible energy minima encountered in the systematic conformational search.
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Affiliation(s)
- Andrew J Beevers
- Department of Biological Sciences, University of Warwick, Coventry, UK
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15
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Beevers AJ, Kukol A. Phospholemman Transmembrane Structure Reveals Potential Interactions with Na+/K+-ATPase. J Biol Chem 2007; 282:32742-8. [PMID: 17698851 DOI: 10.1074/jbc.m703676200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholemman (PLM) is a 72-residue bitopic cardiac transmembrane protein, which acts as a modulator of the Na(+)/K(+)-ATPase and the Na(+)/Ca(2+) exchanger and possibly forms taurine channels in nonheart tissue. This work presents a high resolution structural model obtained from a combination of site-specific infrared spectroscopy and experimentally constrained high throughput molecular dynamics (MD) simulations. Altogether, 37 experimental constraints, including nine long range orientational constraints, have been used during MD simulations in an explicit lipid bilayer/water system. The resulting tetrameric alpha-helical bundle has an average helix tilt of 7.3 degrees and a crossing angle close to 0 degrees . It does not reveal a hydrophilic pore, but instead strong interactions between various residues occlude any pore. The helix-helix packing is unusual, with Gly(19) and Gly(20) pointing to the outside of the helical bundle, facilitating potential interaction with other transmembrane proteins, thus providing a structural basis for the modulatory effect of PLM on the Na(+)/K(+)-ATPase. A two-stage model of interaction between PLM and the Na(+)/K(+)-ATPase is discussed involving PLM-ATPase interaction and subsequent formation of an unstable PLM trimer, which readily interacts with surrounding ATPase molecules. Further unconstrained MD simulations identified other packing models of PLM, one of which could potentially undergo a conformational transition to an open pore.
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Affiliation(s)
- Andrew J Beevers
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
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16
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Samna Soumana O, Garnier N, Genest M. Molecular dynamics simulation approach for the prediction of transmembrane helix–helix heterodimers assembly. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2007; 36:1071-82. [PMID: 17646979 DOI: 10.1007/s00249-007-0195-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 05/11/2007] [Accepted: 05/15/2007] [Indexed: 10/23/2022]
Abstract
Computational methods are useful to identify favorable structures of transmembrane (TM) helix oligomers when experimental data are not available or when they cannot help to interpret helix-helix association. We report here a global search method using molecular dynamics (MD) simulations to predict the structures of transmembrane homo and heterodimers. The present approach is based only on sequence information without any experimental data and is first applied to glycophorin A to validate the protocol and to the HER2-HER3 heterodimer receptor. The method successfully reproduces the experimental structures of the TM domain of glycophorin A (GpA(TM)) with a root mean square deviation of 1.5 A. The search protocol identifies three energetically stable models of the TM domain of HER2-HER3 receptor with favorable helix-helix arrangement, including right-handed and left-handed coiled-coils. The predicted TM structures exhibit the GxxxG-like motif at the dimer interface which is presumed to drive receptor oligomerization. We demonstrate that native structures of TM domain can be predicted without quantitative experimental data. This search protocol could help to predict structures of the TM domain of HER heterodimer family.
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Affiliation(s)
- Oumarou Samna Soumana
- Centre de Biophysique Moléculaire, UPR 4301, CNRS, University of Orléans, rue Charles Sadron, 45071, Orléans Cedex 02, France
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17
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18
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Aller P, Garnier N, Genest M. Transmembrane Helix Packing of ErbB/Neu Receptor in Membrane Environment: A Molecular Dynamics Study. J Biomol Struct Dyn 2006; 24:209-28. [PMID: 17054379 DOI: 10.1080/07391102.2006.10507114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dimerization or oligomerization of the ErbB/Neu receptors are necessary but not sufficient for initiation of receptor signaling. The two intracellular domains must be properly oriented for the juxtaposition of the kinase domains allowing trans-phosphorylation. This suggests that the transmembrane (TM) domain acts as a guide for defining the proper orientation of the intracellular domains. Two structural models, with the two helices either in left-handed or in right-handed coiling have been proposed as the TM domain structure of the active receptor. Because experimental data do not distinguish clearly helix-helix packing, molecular dynamics (MD) simulations are used to investigate the energetic factors that drive Neu TM-TM interactions of the wild and the oncogenic receptor (Val664/Glu mutation) in DMPC or in POPC environments. MD results indicate that helix-lipid interactions in the bilayer core are extremely similar in the two environments and raise the role of the juxtamembrane residues in helix insertion and helix-helix packing. The TM domain shows a greater propensity to adopt a left-handed structure in DMPC, with helices in optimal position for strong inter-helical Hbonds induced by the Glu mutation. In POPC, the right-handed structure is preferentially formed with the participation of water in inter-helical Hbonds. The two structural arrangements of the Neu(TM) helices both with GG4 residue motif in close contact at the interface are permissible in the membrane environment. According to the hypothesis of a monomer-dimer equilibrium of the proteins it is likely that the bilayer imposes structural constraints that favor dimerization-competent structure responsible of the proper topology necessary for receptor activation.
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Affiliation(s)
- Pierre Aller
- Centre de Biophysique Moléculaire, UPR 4301, CNRS, Affiliated to the University of Orléans and to INSERM, rue Charles Sadron, 45071 Orléans Cedex 02, France
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19
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Cuthbertson JM, Bond PJ, Sansom MSP. Transmembrane Helix−Helix Interactions: Comparative Simulations of the Glycophorin A Dimer. Biochemistry 2006; 45:14298-310. [PMID: 17128969 DOI: 10.1021/bi0610911] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The glycophorin helix dimer is a paradigm for the exploration of helix-helix interactions in integral membrane proteins. Two NMR structures of the dimer are known, one in a detergent micelle and one in a lipid bilayer. Multiple (4 x 50 ns) molecular dynamics simulations starting from each of the two NMR structures, with each structure in either a dodecyl phosphocholine (DPC) micelle or a dimyristoyl phosphatidylcholine (DMPC) bilayer, have been used to explore the conformational dynamics of the helix dimer. Analysis of the helix-helix interaction, mediated by the GxxxG sequence motif, suggests convergence of the simulations to a common model. This is closer to the NMR structure determined in a bilayer than to micelle structure. The stable dimer interface in the final simulation model is characterized by (i) Gly/Gly packing and (ii) Thr/Thr interhelix H-bonds. These results demonstrate the ability of extended molecular dynamics simulations in a lipid bilayer environment to refine membrane protein structures or models derived from experimental data obtained in protein/detergent micelles.
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Abstract
A large number of experimental studies have been devoted to quantifying the interaction between transmembrane (TM) helices in detergent micelles and, more recently, in bilayers. Theoretical calculation of association free energy of TM helices would be useful for predicting the propensity of given sequences to oligomerize and for understanding the difference between association in micelles and in bilayers. In this article, the theoretical foundation for calculating the standard association free energy of TM helices is laid out and is applied to glycophorin A in both micelles and bilayers. The standard association free energy is decomposed into the effective energy, translational, rotational, and conformational entropy terms. The effective energy of association is obtained by molecular dynamics simulations in an implicit membrane model. The translational and rotational entropy of association is calculated from the probability distribution of the translational and rotational degrees of freedom obtained from the molecular dynamics simulations. The side-chain conformational entropy of association is estimated from the probability distribution obtained by rigid rotation of all side-chain dihedral angles. The calculated standard association free energy of glycophorin A in N-dodecylphosphocholine micelles is in good agreement with the experimental value. The translational entropy cost is larger, whereas the rotational entropy cost is smaller in bilayers than in micelles. The standard association free energy in 1,2-dimyristoyl-sn-glycero-3-phosphocholine bilayers is calculated to be approximately 1.3 kcal/mol more favorable than in N-dodecylphosphocholine micelles, consistent with available experimental data.
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Affiliation(s)
- Jinming Zhang
- Department of Chemistry, The City College of New York/The City University of New York, New York, New York 10031, USA
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