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Lacabanne D, Wiegand T, Di Cesare M, Orelle C, Ernst M, Jault JM, Meier BH, Böckmann A. Solid-State NMR Reveals Asymmetric ATP Hydrolysis in the Multidrug ABC Transporter BmrA. J Am Chem Soc 2022; 144:12431-12442. [PMID: 35776907 PMCID: PMC9284561 DOI: 10.1021/jacs.2c04287] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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The detailed mechanism
of ATP hydrolysis in ATP-binding cassette
(ABC) transporters is still not fully understood. Here, we employed 31P solid-state NMR to probe the conformational changes and
dynamics during the catalytic cycle by locking the multidrug ABC transporter
BmrA in prehydrolytic, transition, and posthydrolytic states, using
a combination of mutants and ATP analogues. The 31P spectra
reveal that ATP binds strongly in the prehydrolytic state to both
ATP-binding sites as inferred from the analysis of the nonhydrolytic
E504A mutant. In the transition state of wild-type BmrA, the symmetry
of the dimer is broken and only a single site is tightly bound to
ADP:Mg2+:vanadate, while the second site is more ‘open’
allowing exchange with the nucleotides in the solvent. In the posthydrolytic
state, weak binding, as characterized by chemical exchange with free
ADP and by asymmetric 31P–31P two-dimensional
(2D) correlation spectra, is observed for both sites. Revisiting the 13C spectra in light of these findings confirms the conformational
nonequivalence of the two nucleotide-binding sites in the transition
state. Our results show that following ATP binding, the symmetry of
the ATP-binding sites of BmrA is lost in the ATP-hydrolysis step,
but is then recovered in the posthydrolytic ADP-bound state.
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Affiliation(s)
| | - Thomas Wiegand
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Margot Di Cesare
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Cédric Orelle
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Jean-Michel Jault
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Anja Böckmann
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
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2
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The effect of drug binding on specific sites in transmembrane helices 4 and 6 of the ABC exporter MsbA studied by DNP-enhanced solid-state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:833-840. [PMID: 29069570 DOI: 10.1016/j.bbamem.2017.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/09/2017] [Accepted: 10/15/2017] [Indexed: 02/05/2023]
Abstract
MsbA, a homodimeric ABC exporter, translocates its native substrate lipid A as well as a range of smaller, amphiphilic substrates across the membrane. Magic angle sample spinning (MAS) NMR, in combination with dynamic nuclear polarization (DNP) for signal enhancement, has been used to probe two specific sites in transmembrane helices 4 and 6 of full length MsbA embedded in lipid bilayers. Significant chemical shift changes in both sites were observed in the vanadate-trapped state compared to apo state MsbA. The reduced spectral line width indicates a more confined conformational space upon trapping. In the presence of substrates Hoechst 33342 and daunorubicin, further chemical shift changes and line shape alterations mainly in TM6 in the vanadate trapped state were detected. These data illustrate the conformational response of MsbA towards the presence of drugs during the catalytic cycle. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane Proteins edited by Ute Hellmich, Rupak Doshi and Benjamin McIlwain.
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3
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Hellmich UA, Mönkemeyer L, Velamakanni S, van Veen HW, Glaubitz C. Effects of nucleotide binding to LmrA: A combined MAS-NMR and solution NMR study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:3158-65. [PMID: 26449340 DOI: 10.1016/j.bbamem.2015.10.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/25/2015] [Accepted: 10/01/2015] [Indexed: 11/26/2022]
Abstract
ABC transporters are fascinating examples of fine-tuned molecular machines that use the energy from ATP hydrolysis to translocate a multitude of substrates across biological membranes. While structural details have emerged on many members of this large protein superfamily, a number of functional details are still under debate. High resolution structures yield valuable insights into protein function, but it is the combination of structural, functional and dynamic insights that facilitates a complete understanding of the workings of their complex molecular mechanisms. NMR is a technique well-suited to investigate proteins in atomic resolution while taking their dynamic properties into account. It thus nicely complements other structural techniques, such as X-ray crystallography, that have contributed high-resolution data to the architectural understanding of ABC transporters. Here, we describe the heterologous expression of LmrA, an ABC exporter from Lactococcus lactis, in Escherichia coli. This allows for more flexible isotope labeling for nuclear magnetic resonance (NMR) studies and the easy study of LmrA's multidrug resistance phenotype. We use a combination of solid-state magic angle spinning (MAS) on the reconstituted transporter and solution NMR on its isolated nucleotide binding domain to investigate consequences of nucleotide binding to LmrA. We find that nucleotide binding affects the protein globally, but that NMR is also able to pinpoint local dynamic effects to specific residues, such as the Walker A motif's conserved lysine residue.
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Affiliation(s)
- Ute A Hellmich
- Department of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Germany; Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany.
| | - Leonie Mönkemeyer
- Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany; Department of Biophysical Chemistry, J.W. Goethe University, Frankfurt, Germany
| | | | | | - Clemens Glaubitz
- Centre for Biomolecular Magnetic Resonance (BMRZ), J.W. Goethe University, Frankfurt, Germany; Department of Biophysical Chemistry, J.W. Goethe University, Frankfurt, Germany; Cluster of Excellence Macromolecular Complexes Frankfurt, Germany.
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4
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Kunert B, Gardiennet C, Lacabanne D, Calles-Garcia D, Falson P, Jault JM, Meier BH, Penin F, Böckmann A. Efficient and stable reconstitution of the ABC transporter BmrA for solid-state NMR studies. Front Mol Biosci 2014; 1:5. [PMID: 25988146 PMCID: PMC4428385 DOI: 10.3389/fmolb.2014.00005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 05/26/2014] [Indexed: 01/20/2023] Open
Abstract
We present solid-state NMR sample preparation and first 2D spectra of the Bacillus subtilis ATP-binding cassette (ABC) transporter BmrA, a membrane protein involved in multidrug resistance. The homodimeric 130-kDa protein is a challenge for structural characterization due to its membrane-bound nature, size, inherent flexibility and insolubility. We show that reconstitution of this protein in lipids from Bacillus subtilis at a lipid-protein ratio of 0.5 w/w allows for optimal protein insertion in lipid membranes with respect to two central NMR requirements, high signal-to-noise in the spectra and sample stability over a time period of months. The obtained spectra point to a well-folded protein and a highly homogenous preparation, as witnessed by the narrow resonance lines and the signal dispersion typical for the expected secondary structure distribution of BmrA. This opens the way for studies of the different conformational states of the transporter in the export cycle, as well as on interactions with substrates, via chemical-shift fingerprints and sequential resonance assignments.
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Affiliation(s)
- Britta Kunert
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Carole Gardiennet
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Denis Lacabanne
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Daniel Calles-Garcia
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Pierre Falson
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Jean-Michel Jault
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | | | - François Penin
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
| | - Anja Böckmann
- Labex Ecofect, Bases Moleculaires et Structurales des Systemes Infectieux, UMR 5086 CNRS, IBCP, Université de Lyon 1Lyon, France
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5
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Roberson KJ, Brady PN, Sweeney MM, Macnaughtan MA. Methods to identify the NMR resonances of the ¹³C-dimethyl N-terminal amine on reductively methylated proteins. J Vis Exp 2013:e50875. [PMID: 24378713 PMCID: PMC4105138 DOI: 10.3791/50875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a proven technique for protein structure and dynamic studies. To study proteins with NMR, stable magnetic isotopes are typically incorporated metabolically to improve the sensitivity and allow for sequential resonance assignment. Reductive (13)C-methylation is an alternative labeling method for proteins that are not amenable to bacterial host over-expression, the most common method of isotope incorporation. Reductive (13)C-methylation is a chemical reaction performed under mild conditions that modifies a protein's primary amino groups (lysine ε-amino groups and the N-terminal α-amino group) to (13)C-dimethylamino groups. The structure and function of most proteins are not altered by the modification, making it a viable alternative to metabolic labeling. Because reductive (13)C-methylation adds sparse, isotopic labels, traditional methods of assigning the NMR signals are not applicable. An alternative assignment method using mass spectrometry (MS) to aid in the assignment of protein (13)C-dimethylamine NMR signals has been developed. The method relies on partial and different amounts of (13)C-labeling at each primary amino group. One limitation of the method arises when the protein's N-terminal residue is a lysine because the α- and ε-dimethylamino groups of Lys1 cannot be individually measured with MS. To circumvent this limitation, two methods are described to identify the NMR resonance of the (13)C-dimethylamines associated with both the N-terminal α-amine and the side chain ε-amine. The NMR signals of the N-terminal α-dimethylamine and the side chain ε-dimethylamine of hen egg white lysozyme, Lys1, are identified in (1)H-(13)C heteronuclear single-quantum coherence spectra.
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6
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Lange V, Becker-Baldus J, Kunert B, van Rossum BJ, Casagrande F, Engel A, Roske Y, Scheffel FM, Schneider E, Oschkinat H. A MAS NMR study of the bacterial ABC transporter ArtMP. Chembiochem 2010; 11:547-55. [PMID: 20099290 DOI: 10.1002/cbic.200900472] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
ATP-binding cassette (ABC) transport systems facilitate the translocation of substances, like amino acids, across cell membranes energised by ATP hydrolysis. This work describes first structural studies on the ABC transporter ArtMP from Geobacillus stearothermophilus in native lipid environment by magic-angle spinning NMR spectroscopy. The 2D crystals of ArtMP and 3D crystals of isolated ArtP were prepared in different nucleotide-bound or -unbound states. From selectively (13)C,(15)N-labelled ArtP, several sequence-specific assignments were obtained, most of which could be transferred to spectra of ArtMP. Residues Tyr133 and Pro134 protrude directly into the ATP-binding pocket at the interface of the ArtP subunits, and hence, are sensitive monitors for structural changes during nucleotide binding and hydrolysis. Distinct sets of NMR shifts were obtained for ArtP with different phosphorylation states of the ligand. Indications were found for an asymmetric or inhomogeneous state of the ArtP dimer bound with triphosphorylated nucleotides. With this investigation, a model system was established for screening all functional states occurring in one ABC transporter in native lipid environment.
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Affiliation(s)
- Vivien Lange
- NMR-Supported Structural Biology, Leibniz-Institut für Molekulare Pharmakologie, R.-Rössle-Strasse 10, 13125 Berlin, Germany
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7
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Abstract
AbstractIn order to fulfill their function, membrane transport proteins have to cycle through a number of conformational and/or energetic states. Thus, understanding the role of conformational dynamics seems to be the key for elucidation of the functional mechanism of these proteins. However, membrane proteins in general are often difficult to express heterologously and in sufficient amounts for structural studies. It is especially challenging to trap a stable energy minimum, e.g., for crystallographic analysis. Furthermore, crystallization is often only possible by subjecting the protein to conditions that do not resemble its native environment and crystals can only be snapshots of selected conformational states. Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy are complementary methods that offer unique possibilities for studying membrane proteins in their natural membrane environment and for investigating functional conformational changes, lipid interactions, substrate-lipid and substrate-protein interactions, oligomerization states and overall dynamics of membrane transporters. Here, we review recent progress in the field including studies from primary and secondary active transporters.
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8
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Abstract
MsbA is an essential ABC (ATP-binding cassette) transporter involved in lipid A transport across the cytoplasmic membrane of Gram-negative bacteria. The protein has also been linked to efflux of amphipathic drugs. Purified wild-type MsbA was labelled stoichiometrically with the fluorescent probe MIANS [2-(4′-maleimidylanilino)naphthalene-6-sulfonic acid] on C315, which is located within the intracellular domain connecting transmembrane helix 6 and the nucleotide-binding domain. MsbA–MIANS displayed high ATPase activity, and its folding and stability were unchanged. The initial rate of MsbA labelling by MIANS was reduced in the presence of amphipathic drugs, suggesting that binding of these compounds alters the protein conformation. The fluorescence of MsbA–MIANS was saturably quenched by nucleotides, lipid A and various drugs, and estimates of the Kd values for binding fell in the range of 0.35–10 μM. Lipid A and daunorubicin were able to bind to MsbA–MIANS simultaneously, implying that they occupy different binding sites. The effects of nucleotide and lipid A/daunorubicin binding were additive, and binding was not ordered. The Kd of MsbA for binding lipid A was substantially decreased when the daunorubicin binding site was occupied first, and prior binding of nucleotide also modulated lipid A binding affinity. These results indicate that MsbA contains two substrate-binding sites that communicate with both the nucleotide-binding domain and with each other. One is a high affinity binding site for the physiological substrate, lipid A, and the other site interacts with drugs with comparable affinity. Thus MsbA may function as both a lipid flippase and a multidrug transporter.
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9
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Hellmich UA, Haase W, Velamakanni S, van Veen HW, Glaubitz C. Caught in the act: ATP hydrolysis of an ABC-multidrug transporter followed by real-time magic angle spinning NMR. FEBS Lett 2008; 582:3557-62. [PMID: 18817774 DOI: 10.1016/j.febslet.2008.09.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 09/01/2008] [Accepted: 09/14/2008] [Indexed: 10/21/2022]
Abstract
The ATP binding cassette (ABC) transporter LmrA from Lactococcus lactis transports cytotoxic molecules at the expense of ATP. Molecular and kinetic details of LmrA can be assessed by solid-state nuclear magnetic resonance (ssNMR), if functional reconstitution at a high protein-lipid ratio can be achieved and the kinetic rate constants are small enough. In order to follow ATP hydrolysis directly by 31P-magic angle spinning (MAS) nuclear magnetic resonance (NMR), we generated such conditions by reconstituting LmrA-dK388, a mutant with slower ATP turnover rate, at a protein-lipid ration of 1:150. By analysing time-resolved 31P spectra, protein activity has been directly assessed. These data demonstrate the general possibility to perform ssNMR studies on a fully active full length ABC transporter and also form the foundation for further kinetic studies on LmrA by NMR.
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Affiliation(s)
- Ute A Hellmich
- Institute for Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, Cluster of Excellence Macromolecular Complexes, J.W. Goethe University, Frankfurt am Main, Germany
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10
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Shastri S, Vonck J, Pfleger N, Haase W, Kuehlbrandt W, Glaubitz C. Proteorhodopsin: characterisation of 2D crystals by electron microscopy and solid state NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:3012-9. [PMID: 17964280 DOI: 10.1016/j.bbamem.2007.10.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 09/29/2007] [Accepted: 10/02/2007] [Indexed: 11/15/2022]
Abstract
Proteorhodopsin (PR) a recent addition to retinal type 1 protein family, is a bacterial homologue of archaeal bacteriorhodopsin. It was found to high abundance in gamma-proteobacteria in the photic zone of the oceans and has been shown to act as a photoactive proton pump. It is therefore involved in the utilisation of light energy for energy production within the cell. Based on data from biodiversity screens, hundreds of variants were discovered worldwide, which are spectrally tuned to the available light at different locations in the sea. Here, we present a characterisation of 2D crystals of the green variant of proteorhodopsin by electron microscopy and solid state NMR. 2D crystal formation with hexagonal protein packing was observed under a very wide range of conditions indicating that PR might be also closely packed under native conditions. A low-resolution 2D projection map reveals a ring-shaped oligomeric assembly of PR. The protein state was analysed by 15N MAS NMR on lysine, tryptophan and methionine labelled samples. The chemical shift of the protonated Schiff base was almost identical to non-crystalline preparations. All residues could be cross-polarised in non-frozen samples. Lee-Goldberg cross-polarisation has been used to probe protein backbone mobility.
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Affiliation(s)
- Sarika Shastri
- Institute of Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe University, Max von Laue Str. 9, D-60438 Frankfurt am Main, Germany
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11
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Nakajima T, Nakayama K, Shimizu I. Synthesis of isotope-labelled [1-13C]-amino acids from13CO2. J Labelled Comp Radiopharm 2007. [DOI: 10.1002/jlcr.1379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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13
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Basting D, Lehner I, Lorch M, Glaubitz C. Investigating transport proteins by solid state NMR. Naunyn Schmiedebergs Arch Pharmacol 2006; 372:451-64. [PMID: 16506075 DOI: 10.1007/s00210-006-0039-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 01/17/2006] [Indexed: 10/25/2022]
Abstract
Transporters form an interesting and complex class of membrane proteins. Many of them are potential drug targets due to their role in translocation of ions, small molecules and peptides across the membrane or due to their role in multidrug resistance. Hence elucidating their structure and mechanism is of great importance and may lead to a host of new drugs and methods to alter or inhibit their function. Solid state NMR is an emerging technique for investigating transport proteins. Along with other biochemical and biophysical techniques solid state NMR can provide data on drug binding, protein dynamics and structure at the interface between structural biology and functional analysis. Here, we review solid state NMR applications to primary active and secondary transporters involved in translocation of small molecules. We discuss current experimental limitations and give an overall perspective on how the technique may be used to address some pertinent questions relevant to transporters.
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Affiliation(s)
- Daniel Basting
- Institute for Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J.W. Goethe Universität, Marie-Curie Str. 9, 60439, Frankfurt am Main, Germany
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14
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Lorch M, Faham S, Kaiser C, Weber I, Mason AJ, Bowie JU, Glaubitz C. How to prepare membrane proteins for solid-state NMR: A case study on the alpha-helical integral membrane protein diacylglycerol kinase from E. coli. Chembiochem 2006; 6:1693-700. [PMID: 16138309 DOI: 10.1002/cbic.200500054] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Several studies have demonstrated that it is viable to use microcrystalline preparations of water-soluble proteins as samples in solid-state NMR experiments [1-5]. Here, we investigate whether this approach holds any potential for studying water-insoluble systems, namely membrane proteins. For this case study, we have prepared proteoliposomes and small crystals of the alpha-helical membrane-protein diacylglycerol kinase (DGK). Preparations were characterised by 13C- and 15N-cross-polarization magic-angle spinning (CPMAS) NMR. It was found that crystalline samples produce better-resolved spectra than proteoliposomes. This makes them more suitable for structural NMR experiments. However, reconstitution is the method of choice for biophysical studies by solid-state NMR. In addition, we discuss the identification of lipids bound to membrane-protein crystals by 31P-MAS NMR.
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Affiliation(s)
- Mark Lorch
- Centre for Biomolecular Magnetic Resonance and Institut für Biophysikalische Chemie, J. W. Goethe Universität, Marie-Curie-Strasse 9, 60439 Frankfurt, Germany
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15
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Lorch M, Lehner I, Siarheyeva A, Basting D, Pfleger N, Manolikas T, Glaubitz C. NMR and fluorescence spectroscopy approaches to secondary and primary active multidrug efflux pumps. Biochem Soc Trans 2005; 33:873-7. [PMID: 16042617 DOI: 10.1042/bst0330873] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Multidrug efflux pumps are found in all major transporter families. Along with a lack of three-dimensional structure information, the mechanism of drug recognition, energy coupling with drug translocation and the catalytic cycle are so far not understood. In the present study, we present first data of a fluorescence-based assay to study the pH-gradient-mediated activity of the multidrug antiporter EmrE, by co-reconstitution with the light-driven proton pump bacteriorhodopsin. In addition to biochemical approaches, the emerging technique, solid-state NMR, can be used for the investigation of these transporters. A number of experiments based on MAS (magic angle sample spinning) NMR are available to provide data on protein structure and dynamics, drug binding and protein–lipid interactions. However, these experiments dictate a number of constraints with respect to sample preparation that will be discussed for proteins from the SMR (small multidrug resistance transporter) family. In addition, 2H-NMR is used to probe protein mobility of Lactococcus lactis ABC transporter, LmrA.
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Affiliation(s)
- M Lorch
- Institute for Biophysical Chemistry, Centre for Biomolecular Magnetic Resonance, J. W. Goethe Universität Frankfurt, Marie Curie Str. 9, 60439 Frankfurt am Main, Germany
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16
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Luca S, Heise H, Lange A, Baldus M. Investigation of Ligand-Receptor Systems by High-Resolution Solid-State NMR: Recent Progress and Perspectives. Arch Pharm (Weinheim) 2005; 338:217-28. [PMID: 15938000 DOI: 10.1002/ardp.200400991] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Solid-state Nuclear Magnetic Resonance (NMR) provides a general method to study molecular structure and dynamics in a non-crystalline and insoluble environment. We discuss the latest methodological progress to construct 3D molecular structures from solid-state NMR data obtained under magic-angle-spinning conditions. As shown for the neurotensin/NTS-1 system, these methods can be readily applied to the investigation of ligand-binding to G-protein coupled receptors.
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Affiliation(s)
- Sorin Luca
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, Bethesda, Maryland 20892, USA
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17
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McDermott AE. Structural and dynamic studies of proteins by solid-state NMR spectroscopy: rapid movement forward. Curr Opin Struct Biol 2005; 14:554-61. [PMID: 15465315 DOI: 10.1016/j.sbi.2004.09.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 08/24/2004] [Accepted: 09/03/2004] [Indexed: 10/26/2022]
Abstract
Starting only a few years ago, many solid-state NMR spectroscopy laboratories have become engaged in solving the complete structures of biological macromolecules using high-resolution methods based on magic angle spinning. These efforts typically involve structurally homogeneous samples, and utilize recently developed pulse sequences for the sequential correlation of resonances, the detection of tertiary contacts and the characterization of torsion angles. Thereby, systems have been studied that evaded other, more established, structure determination methods.
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Affiliation(s)
- Ann E McDermott
- Columbia University, Department of Chemistry, MC 3113, 3000 Broadway, New York, New York 10027, USA.
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