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Taware PP, Jain MG, Raran-Kurussi S, Agarwal V, Madhu PK, Mote KR. Measuring Dipolar Order Parameters in Nondeuterated Proteins Using Solid-State NMR at the Magic-Angle-Spinning Frequency of 100 kHz. J Phys Chem Lett 2023; 14:3627-3635. [PMID: 37026698 DOI: 10.1021/acs.jpclett.3c00492] [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: 06/19/2023]
Abstract
Proteins are dynamic molecules, relying on conformational changes to carry out function. Measurement of these conformational changes can provide insight into how function is achieved. For proteins in the solid state, this can be done by measuring the decrease in the strength of anisotropic interactions due to motion-induced fluctuations. The measurement of one-bond heteronuclear dipole-dipole coupling at magic-angle-spinning (MAS) frequencies >60 kHz is ideal for this purpose. However, rotational-echo double resonance (REDOR), an otherwise gold-standard technique for the quantitative measurement of these couplings, is difficult to implement under these conditions, especially in nondeuterated samples. We present here a combination of strategies based on REDOR variants ϵ-REDOR and DEDOR (deferred REDOR) and simultaneously measure residue-specific 15N-1H and 13Cα-1Hα dipole-dipole couplings in nondeuterated systems at the MAS frequency of 100 kHz. These strategies open up avenues to access dipolar order parameters in a variety of systems at the increasingly fast MAS frequencies that are now available.
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Affiliation(s)
- Pravin P Taware
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Mukul G Jain
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Sreejith Raran-Kurussi
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Vipin Agarwal
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - P K Madhu
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500 046, Telangana, India
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Pacull EM, Sendker F, Bernhard F, Scheidt HA, Schmidt P, Huster D, Krug U. Integration of Cell-Free Expression and Solid-State NMR to Investigate the Dynamic Properties of Different Sites of the Growth Hormone Secretagogue Receptor. Front Pharmacol 2020; 11:562113. [PMID: 33324203 PMCID: PMC7723455 DOI: 10.3389/fphar.2020.562113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/21/2020] [Indexed: 01/09/2023] Open
Abstract
Cell-free expression represents an attractive method to produce large quantities of selectively labeled protein for NMR applications. Here, cell-free expression was used to label specific regions of the growth hormone secretagogue receptor (GHSR) with NMR-active isotopes. The GHSR is a member of the class A family of G protein-coupled receptors. A cell-free expression system was established to produce the GHSR in the precipitated form. The solubilized receptor was refolded in vitro and reconstituted into DMPC lipid membranes. Methionines, arginines, and histidines were chosen for 13C-labeling as they are representative for the transmembrane domains, the loops and flanking regions of the transmembrane α-helices, and the C-terminus of the receptor, respectively. The dynamics of the isotopically labeled residues was characterized by solid-state NMR measuring motionally averaged 1H-13C dipolar couplings, which were converted into molecular order parameters. Separated local field DIPSHIFT experiments under magic-angle spinning conditions using either varying cross polarization contact times or direct excitation provided order parameters for these residues showing that the C-terminus was the segment with the highest motional amplitude. The loop regions and helix ends as well as the transmembrane regions of the GHSR represent relatively rigid segments in the overall very flexible receptor molecule. Although no site resolution could be achieved in the experiments, the previously reported highly dynamic character of the receptor concluded from uniformly 13C labeled receptor samples could be further specified by this segmental labeling approach, leading to a more diversified understanding of the receptor dynamics under equilibrium conditions.
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Affiliation(s)
- Emelyne M Pacull
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | - Franziska Sendker
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | - Frank Bernhard
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt am Main, Germany.,Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Holger A Scheidt
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | - Peter Schmidt
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
| | - Ulrike Krug
- Institute for Medical Physics and Biophysics, University of Leipzig, Leipzig, Germany
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Jain MG, Rajalakshmi G, Madhu PK, Agarwal V, Mote KR. Overcoming Prohibitively Large Radiofrequency Demands for the Measurement of Internuclear Distances with Solid-State NMR under Fast Magic-Angle Spinning. J Phys Chem B 2020; 124:1444-1451. [DOI: 10.1021/acs.jpcb.9b11849] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Mukul G. Jain
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad, Telangana 500107, India
| | - G. Rajalakshmi
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad, Telangana 500107, India
| | - P. K. Madhu
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad, Telangana 500107, India
| | - Vipin Agarwal
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad, Telangana 500107, India
| | - Kaustubh R. Mote
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad, Telangana 500107, India
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Expression, Functional Characterization, and Solid-State NMR Investigation of the G Protein-Coupled GHS Receptor in Bilayer Membranes. Sci Rep 2017; 7:46128. [PMID: 28387359 PMCID: PMC5384189 DOI: 10.1038/srep46128] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 03/13/2017] [Indexed: 01/14/2023] Open
Abstract
The expression, functional reconstitution and first NMR characterization of the human growth hormone secretagogue (GHS) receptor reconstituted into either DMPC or POPC membranes is described. The receptor was expressed in E. coli. refolded, and reconstituted into bilayer membranes. The molecule was characterized by 15N and 13C solid-state NMR spectroscopy in the absence and in the presence of its natural agonist ghrelin or an inverse agonist. Static 15N NMR spectra of the uniformly labeled receptor are indicative of axially symmetric rotational diffusion of the G protein-coupled receptor in the membrane. In addition, about 25% of the 15N sites undergo large amplitude motions giving rise to very narrow spectral components. For an initial quantitative assessment of the receptor mobility, 1H-13C dipolar coupling values, which are scaled by molecular motions, were determined quantitatively. From these values, average order parameters, reporting the motional amplitudes of the individual receptor segments can be derived. Average backbone order parameters were determined with values between 0.56 and 0.69, corresponding to average motional amplitudes of 40–50° of these segments. Differences between the receptor dynamics in DMPC or POPC membranes were within experimental error. Furthermore, agonist or inverse agonist binding only insignificantly influenced the average molecular dynamics of the receptor.
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Bärenwald R, Achilles A, Lange F, Ferreira TM, Saalwächter K. Applications of Solid-State NMR Spectroscopy for the Study of Lipid Membranes with Polyphilic Guest (Macro)Molecules. Polymers (Basel) 2016; 8:E439. [PMID: 30974716 PMCID: PMC6432237 DOI: 10.3390/polym8120439] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/01/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022] Open
Abstract
The incorporation of polymers or smaller complex molecules into lipid membranes allows for property modifications or the introduction of new functional elements. The corresponding molecular-scale details, such as changes in dynamics or features of potential supramolecular structures, can be studied by a variety of solid-state NMR techniques. Here, we review various approaches to characterizing the structure and dynamics of the guest molecules as well as the lipid phase structure and dynamics by different high-resolution magic-angle spinning proton and 13C NMR experiments as well as static 31P NMR experiments. Special emphasis is placed upon the incorporation of novel synthetic polyphilic molecules such as shape-persistent T- and X-shaped molecules as well as di- and tri-block copolymers. Most of the systems studied feature dynamic heterogeneities, for instance those arising from the coexistence of different phases; possibilities for a quantitative assessment are of particular concern.
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Affiliation(s)
- Ruth Bärenwald
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, D-06120 Halle, Germany
| | - Anja Achilles
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, D-06120 Halle, Germany
| | - Frank Lange
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, D-06120 Halle, Germany
| | - Tiago Mendes Ferreira
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, D-06120 Halle, Germany
| | - Kay Saalwächter
- Institut für Physik-NMR, Martin-Luther-Universität Halle-Wittenberg, D-06120 Halle, Germany.
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Achilles A, Bärenwald R, Lechner BD, Werner S, Ebert H, Tschierske C, Blume A, Bacia K, Saalwächter K. Self-Assembly of X-Shaped Bolapolyphiles in Lipid Membranes: Solid-State NMR Investigations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:673-682. [PMID: 26735449 DOI: 10.1021/acs.langmuir.5b03712] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A novel class of rigid-rod bolapolyphilic molecules with three philicities (rigid aromatic core, mobile aliphatic side chains, polar end groups) has recently been demonstrated to incorporate into and span lipid membranes, and to exhibit a rich variety of self-organization modes, including macroscopically ordered snowflake structures with 6-fold symmetry. In order to support a structural model and to better understand the self-organization on a molecular scale, we here report on proton and carbon-13 high-resolution magic-angle spinning solid-state NMR investigations of two different bolapolyphiles (BPs) in model membranes of two different phospholipids (DPPC, DOPC). We elucidate the changes in molecular dynamics associated with three new phase transitions detected by calorimetry in composite membranes of different composition, namely, a change in π-π-packing, the melting of lipid tails associated with the superstructure, and the dissolution and onset of free rotation of the BPs. We derive dynamic order parameters associated with different H-H and C-H bond directions of the BPs, demonstrating that the aromatic cores are well packed below the final phase transition, showing only 180° flips of the phenyl ring, and that they perform free rotations with additional oscillations of the long axis when dissolved in the fluid membrane. Our data suggests that BPs not only form ordered superstructures, but also rather homogeneously dispersed π-packed filaments within the lipid gel phase, thus reducing the corrugation of large vesicles.
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Affiliation(s)
- Anja Achilles
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Ruth Bärenwald
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Bob-Dan Lechner
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Stefan Werner
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Helgard Ebert
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Carsten Tschierske
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Alfred Blume
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Kirsten Bacia
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
| | - Kay Saalwächter
- Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany
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Bärenwald R, Goerlitz S, Godehardt R, Osichow A, Tong Q, Krumova M, Mecking S, Saalwächter K. Local Flips and Chain Motion in Polyethylene Crystallites: A Comparison of Melt-Crystallized Samples, Reactor Powders, and Nanocrystals. Macromolecules 2014. [DOI: 10.1021/ma500691k] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Ruth Bärenwald
- Institut
für Physik − NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.
7, D-06120 Halle, Germany
| | - Sylvia Goerlitz
- Institut
für Physik − Allgemeine Werkstoffwissenschaften, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle, Germany
| | - Reinhold Godehardt
- Institut
für Physik − Allgemeine Werkstoffwissenschaften, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle, Germany
| | - Anna Osichow
- Chemische
Materialwissenschaft, Fachbereich Chemie, Universität Konstanz, Universitätsstr. 10, D-78457 Konstanz, Germany
| | - Qiong Tong
- Chemische
Materialwissenschaft, Fachbereich Chemie, Universität Konstanz, Universitätsstr. 10, D-78457 Konstanz, Germany
| | - Marina Krumova
- Chemische
Materialwissenschaft, Fachbereich Chemie, Universität Konstanz, Universitätsstr. 10, D-78457 Konstanz, Germany
| | - Stefan Mecking
- Chemische
Materialwissenschaft, Fachbereich Chemie, Universität Konstanz, Universitätsstr. 10, D-78457 Konstanz, Germany
| | - Kay Saalwächter
- Institut
für Physik − NMR, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str.
7, D-06120 Halle, Germany
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