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Gao Y, Saccuzzo EG, Hill SE, Huard DJE, Robang AS, Lieberman RL, Paravastu AK. Structural Arrangement within a Peptide Fibril Derived from the Glaucoma-Associated Myocilin Olfactomedin Domain. J Phys Chem B 2021; 125:2886-2897. [PMID: 33683890 DOI: 10.1021/acs.jpcb.0c11460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Myocilin-associated glaucoma is a new addition to the list of diseases linked to protein misfolding and amyloid formation. Single point variants of the ∼257-residue myocilin olfactomedin domain (mOLF) lead to mutant myocilin aggregation. Here, we analyze the 12-residue peptide P1 (GAVVYSGSLYFQ), corresponding to residues 326-337 of mOLF, previously shown to form amyloid fibrils in vitro and in silico. We applied solid-state NMR structural measurements to test the hypothesis that P1 fibrils adopt one of three predicted structures. Our data are consistent with a U-shaped fibril arrangement for P1, one that is related to the U-shape predicted previously in silico. Our data are also consistent with an antiparallel fibril arrangement, likely driven by terminal electrostatics. Our proposed structural model is reminiscent of fibrils formed by the Aβ(1-40) Iowa mutant peptide, but with a different arrangement of molecular turn regions. Taken together, our results strengthen the connection between mOLF fibrils and the broader amylome and contribute to our understanding of the fundamental molecular interactions governing fibril architecture and stability.
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Jardón-Álvarez D, Kahn N, Houben L, Leskes M. Oxygen Vacancy Distribution in Yttrium-Doped Ceria from 89Y- 89Y Correlations via Dynamic Nuclear Polarization Solid-State NMR. J Phys Chem Lett 2021; 12:2964-2969. [PMID: 33730494 PMCID: PMC8006133 DOI: 10.1021/acs.jpclett.1c00221] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/12/2021] [Indexed: 05/25/2023]
Abstract
Comprehending the oxygen vacancy distribution in oxide ion conductors requires structural insights over various length scales: from the local coordination preferences to the possible formation of agglomerates comprising a large number of vacancies. In Y-doped ceria, 89Y NMR enables differentiation of yttrium sites by quantification of the oxygen vacancies in their first coordination sphere. Because of the extremely low sensitivity of 89Y, longer-range information was so far not available from NMR. Herein, we utilize metal ion-based dynamic nuclear polarization, where polarization from Gd(III) dopants provides large sensitivity enhancements homogeneously throughout the bulk of the sample. This enables following 89Y-89Y homonuclear dipolar correlations and probing the local distribution of yttrium sites, which show no evidence of the formation of oxygen vacancy rich regions. The presented approach can provide valuable structural insights for designing oxide ion conductors.
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Affiliation(s)
- Daniel Jardón-Álvarez
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Nitzan Kahn
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Lothar Houben
- Department
of Chemical Research Support, Weizmann Institute
of Science, Rehovot 76100, Israel
| | - Michal Leskes
- Department
of Materials and Interfaces, Weizmann Institute
of Science, Rehovot 76100, Israel
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3
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Roos M, Mandala VS, Hong M. Determination of Long-Range Distances by Fast Magic-Angle-Spinning Radiofrequency-Driven 19F- 19F Dipolar Recoupling NMR. J Phys Chem B 2018; 122:9302-9313. [PMID: 30211552 DOI: 10.1021/acs.jpcb.8b06878] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanometer-range distances are important for restraining the three-dimensional structure and oligomeric assembly of proteins and other biological molecules. Solid-state NMR determination of protein structures typically utilizes 13C-13C and 13C-15N distance restraints, which can only be measured up to ∼7 Å because of the low gyromagnetic ratios of these nuclear spins. To extend the distance reach of NMR, one can harvest the power of 19F, whose large gyromagnetic ratio in principle allows distances up to 2 nm to be measured. However, 19F possesses large chemical shift anisotropies (CSAs) as well as large isotropic chemical shift dispersions, which pose challenges to dipolar coupling measurements. Here, we demonstrate 19F-19F distance measurements at high magnetic fields under fast magic-angle spinning (MAS) using radiofrequency-driven dipolar recoupling (RFDR). We show that 19F-19F cross-peaks for distances up to 1 nm can be readily observed in two-dimensional 19F-19F correlation spectra using less than 5 ms of RFDR mixing. This efficient 19F-19F dipolar recoupling is achieved using practically accessible MAS frequencies of 15-55 kHz, moderate 19F radio frequency field strengths, and no 1H decoupling. Experiments and simulations show that the fastest polarization transfer for aromatic fluorines with the highest distance accuracy is achieved using either fast MAS (e.g., 60 kHz) with large pulse duty cycles (>50%) or slow MAS with strong 19F pulses. Fast MAS considerably reduces relaxation losses during the RFDR π-pulse train, making finite-pulse RFDR under fast-MAS the method of choice. Under intermediate MAS frequencies (25-40 kHz) and intermediate pulse duty cycles (15-30%), the 19F CSA tensor orientation has a quantifiable effect on the polarization transfer rate; thus, the RFDR buildup curves encode both distance and orientation information. At fast MAS, the impact of CSA orientation is minimized, allowing pure distance restraints to be extracted. We further investigate how relayed transfer and dipolar truncation in multifluorine environments affect polarization transfer. This fast-MAS 19F RFDR approach is complementary to 19F spin diffusion for distance measurements and will be the method of choice under high-field fast-MAS conditions that are increasingly important for protein structure determination by solid-state NMR.
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Affiliation(s)
- Matthias Roos
- Department of Chemistry , Massachusetts Institute of Technology , 170 Albany Street , Cambridge , Massachusetts 02139 , United States
| | - Venkata S Mandala
- Department of Chemistry , Massachusetts Institute of Technology , 170 Albany Street , Cambridge , Massachusetts 02139 , United States
| | - Mei Hong
- Department of Chemistry , Massachusetts Institute of Technology , 170 Albany Street , Cambridge , Massachusetts 02139 , United States
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4
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Abstract
We describe a more broad-banded version of the DREAM double-quantum dipolar-recoupling sequence, which is devised by superimposing a phase-alternating RF irradiation scheme, that is, XiX pulses, on top of the original DREAM sequence. We call this sequence XiX(CW) DREAM. The recoupling conditions and the corresponding first-order effective Hamiltonian are analyzed using triple-mode Floquet theory. The performance of the XiX(CW) DREAM sequence is compared to the original DREAM sequence by numerical simulations and experiments on small model substances and the model protein ubiquitin. The results confirm that XiX(CW) DREAM shows a wider recoupling bandwidth compared to that of DREAM, therefore making the choice for the position of the carrier frequency less critical.
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Affiliation(s)
- Kong Ooi Tan
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Anders B Nielsen
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Beat H Meier
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Matthias Ernst
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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5
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Wang S, Ladizhansky V. Recent advances in magic angle spinning solid state NMR of membrane proteins. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2014; 82:1-26. [PMID: 25444696 DOI: 10.1016/j.pnmrs.2014.07.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2014] [Revised: 07/16/2014] [Accepted: 07/20/2014] [Indexed: 05/14/2023]
Abstract
Membrane proteins mediate many critical functions in cells. Determining their three-dimensional structures in the native lipid environment has been one of the main objectives in structural biology. There are two major NMR methodologies that allow this objective to be accomplished. Oriented sample NMR, which can be applied to membrane proteins that are uniformly aligned in the magnetic field, has been successful in determining the backbone structures of a handful of membrane proteins. Owing to methodological and technological developments, Magic Angle Spinning (MAS) solid-state NMR (ssNMR) spectroscopy has emerged as another major technique for the complete characterization of the structure and dynamics of membrane proteins. First developed on peptides and small microcrystalline proteins, MAS ssNMR has recently been successfully applied to large membrane proteins. In this review we describe recent progress in MAS ssNMR methodologies, which are now available for studies of membrane protein structure determination, and outline a few examples, which highlight the broad capability of ssNMR spectroscopy.
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Affiliation(s)
- Shenlin Wang
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing 100871, China; College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
| | - Vladimir Ladizhansky
- Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada; Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
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6
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7
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SivaRanjan U, Ramachandran R. Unraveling multi-spin effects in rotational resonance nuclear magnetic resonance using effective reduced density matrix theory. J Chem Phys 2014; 140:054101. [DOI: 10.1063/1.4863212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Li J, van der Wel PCA. Spinning-rate encoded chemical shift correlations from rotational resonance solid-state NMR experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:117-24. [PMID: 23475055 PMCID: PMC3635064 DOI: 10.1016/j.jmr.2013.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/22/2013] [Accepted: 02/04/2013] [Indexed: 05/23/2023]
Abstract
Structural measurements in magic-angle-spinning (MAS) solid-state NMR rely heavily on (13)C-(13)C distance measurements. Broadbanded recoupling methods are used to generate many cross-peaks, but have complex polarization transfer mechanisms that limit the precision of distance constraints and can suffer from weak intensities for distant peaks due to relaxation, the broad distribution of polarization, as well as dipolar truncation. Frequency-selective methods that feature narrow-banded recoupling can reduce these effects. Indeed, rotational resonance (R(2)) experiments have found application in many different biological systems, where they have afforded improved precision and accuracy. Unfortunately, a highly selective transfer mechanism also leads to few cross-peaks in the resulting spectra, which complicates the extraction of multiple constraints. R(2)-width (R(2)W) measurements that scan a range of MAS rates to probe the R(2) matching conditions of one or more sites can improve precision, and also permit multiple simultaneous distance measurements. However, multidimensional R(2)W can be very time-consuming. Here, we present an approach that facilitates the acquisition of 2D-like spectra based on a series of 1D R(2)W experiments, by taking advantage of the chemical shift information encoded in the MAS rates where matching occurs. This yields a more time-efficient experiment with many of the benefits of more conventional multidimensional R(2)W measurements. The obtained spectra reveal long-distance (13)C-(13)C cross-peaks resulting from R(2)-mediated polarization transfer. This experiment also enables the efficient setup and targeted implementation of traditional R(2) or R(2)W experiments. Analogous applications may extend to other variable-MAS and frequency-selective solid-state NMR experiments.
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Affiliation(s)
- Jun Li
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, USA
| | - Patrick C. A. van der Wel
- Department of Structural Biology, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, 3501 Fifth Ave, Pittsburgh, Pennsylvania 15260, USA
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9
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Giffard M, Hediger S, Lewandowski JR, Bardet M, Simorre JP, Griffin RG, De Paëpe G. Compensated second-order recoupling: application to third spin assisted recoupling. Phys Chem Chem Phys 2012; 14:7246-55. [PMID: 22513727 PMCID: PMC4440590 DOI: 10.1039/c2cp40406k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We consider the effect of phase shifts in the context of second-order recoupling techniques in solid-state NMR. Notably we highlight conditions leading to significant improvements for the Third Spin Assisted Recoupling (TSAR) mechanism and demonstrate the benefits of resulting techniques for detecting long-distance transfer in biomolecular systems. The modified pulse sequences of PAR and PAIN-CP, Phase-Shifted Proton Assisted Recoupling (AH-PS-PAR) and Phase-Shifted Proton-Assisted Insensitive Nuclei Cross Polarization (ABH-PS-PAIN-CP), still rely on cross terms between heteronuclear dipolar couplings involving assisting protons that mediate zero-quantum polarization transfer between low-γ nuclei ((13)C-(13)C, (15)N-(15)N, (15)N-(13)C polarization transfer). Using Average Hamiltonian Theory we show that phase inversion compensates off-resonance contributions and yields improved polarization transfer as well as substantial broadening of the matching conditions. PS-TSAR greatly improves on the standard TSAR based methods because it alleviates their sensitivity to precise RF settings which significantly enhances robustness of the experiments. We demonstrate these new methods on a 19.6 kDa protein (U-[(15)N, (13)C]-YajG) at high magnetic fields (up to 900 MHz (1)H frequency) and fast sample spinning (up to 65 kHz MAS frequency).
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Affiliation(s)
- Mathilde Giffard
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | - Sabine Hediger
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | | | - Michel Bardet
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale, UMR 5075 (CEA/CNRS/UJF), 38027 Grenoble, France
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Gaël De Paëpe
- Laboratoire de Chimie Inorganique et Biologique, UMR-E3 (CEA/UJF) and CNRS, CEA/DSM/INAC–38054, Grenoble, France
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10
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Reutter S, Privalov A, Buntkowsky G, Fujara F. Rotational Resonance in milli-tesla fields detected by Field Cycling NMR. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2012; 41:74-77. [PMID: 22239819 DOI: 10.1016/j.ssnmr.2011.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 12/20/2011] [Accepted: 12/26/2011] [Indexed: 05/31/2023]
Abstract
Rotational Resonance (R(2)) between different spin Zeeman levels in samples of adamantane C(10)H(16) (homonuclear R(2)) and a mixture of C(10)H(16) and C(10)D(16) (both homonuclear and heteronuclear R(2)) has been studied. A Field Cycling NMR instrument was used to match the external field frequency ν(0) to a fixed frequency of sample rotation ν(r) at ν(r) = 40, 50 or 60 kHz. Rotational Resonance is observed at rational frequency ratios of ν(0)/ν(r), such as 12, 23, 32 and 1. The method may prove to become a useful tool for the determination of spin-spin distances in condensed matter.
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Affiliation(s)
- S Reutter
- Institut für Festkörperphysik, TU Darmstadt, Hochschulstr 6, 64289 Darmstadt, Germany.
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11
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Chan JCC. Solid-state NMR techniques for the structural determination of amyloid fibrils. Top Curr Chem (Cham) 2011; 306:47-88. [PMID: 21630137 DOI: 10.1007/128_2011_154] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This review discusses the solid-state NMR techniques developed for the study of amyloid fibrils. Literature up to the end of 2010 has been surveyed and the materials are organized according to five categories, viz. homonuclear dipolar recoupling and polarization transfer via J-coupling, heteronuclear dipolar recoupling, correlation spectroscopy, recoupling of chemical shift anisotropy, and tensor correlation. Our emphasis is on the NMR techniques and their practical aspects. The biological implications of the results obtained for amyloid fibrils are only briefly discussed. Our main objective is to showcase the power of NMR in the study of biological unoriented solids.
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Affiliation(s)
- Jerry C C Chan
- Department of Chemistry, National Taiwan University, Taipei, Taiwan.
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12
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van der Wel PC, Lewandowski JR, Griffin RG. Structural characterization of GNNQQNY amyloid fibrils by magic angle spinning NMR. Biochemistry 2010; 49:9457-69. [PMID: 20695483 PMCID: PMC3026921 DOI: 10.1021/bi100077x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Several human diseases are associated with the formation of amyloid aggregates, but experimental characterization of these amyloid fibrils and their oligomeric precursors has remained challenging. Experimental and computational analysis of simpler model systems has therefore been necessary, for instance, on the peptide fragment GNNQQNY7−13 of yeast prion protein Sup35p. Expanding on a previous publication, we report here a detailed structural characterization of GNNQQNY fibrils using magic angle spinning (MAS) NMR. On the basis of additional chemical shift assignments we confirm the coexistence of three distinct peptide conformations within the fibrillar samples, as reflected in substantial chemical shift differences. Backbone torsion angle measurements indicate that the basic structure of these coexisting conformers is an extended β-sheet. We structurally characterize a previously identified localized distortion of the β-strand backbone specific to one of the conformers. Intermolecular contacts are consistent with each of the conformers being present in its own parallel and in-register sheet. Overall the MAS NMR data indicate a substantial difference between the structure of the fibrillar and crystalline forms of these peptides, with a clearly increased complexity in the GNNQQNY fibril structure. These experimental data can provide guidance for future work, both experimental and theoretical, and provide insights into the distinction between fibril growth and crystal formation.
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Affiliation(s)
| | | | - Robert G. Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
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Caporini MA, Bajaj VS, Veshtort M, Fitzpatrick A, MacPhee CE, Vendruscolo M, Dobson CM, Griffin RG. Accurate determination of interstrand distances and alignment in amyloid fibrils by magic angle spinning NMR. J Phys Chem B 2010; 114:13555-61. [PMID: 20925357 PMCID: PMC2959142 DOI: 10.1021/jp106675h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amyloid fibrils are structurally ordered aggregates of proteins whose formation is associated with many neurodegenerative and other diseases. For that reason, their high-resolution structures are of considerable interest and have been studied using a wide range of techniques, notably electron microscopy, X-ray diffraction, and magic angle spinning (MAS) NMR. Because of the excellent resolution in the spectra, MAS NMR is uniquely capable of delivering site-specific, atomic resolution information about all levels of amyloid structure: (1) the monomer, which packs into several (2) protofilaments that in turn associate to form a (3) fibril. Building upon our high-resolution structure of the monomer of an amyloid-forming peptide from transthyretin (TTR(105-115)), we introduce single 1-(13)C labeled amino acids at seven different sites in the peptide and measure intermolecular carbonyl-carbonyl distances with an accuracy of ~0.11 A. Our results conclusively establish a parallel, in register, topology for the packing of this peptide into a β-sheet and provide constraints essential for the determination of an atomic resolution structure of the fibril. Furthermore, the approach we employ, based on a combination of a double-quantum filtered variant of the DRAWS recoupling sequence and multispin numerical simulations in SPINEVOLUTION, is general and should be applicable to a wide range of systems.
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Affiliation(s)
- Marc A Caporini
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Spano J, Wi S. Dipolar-coupling-mediated total correlation spectroscopy in solid-state 13C NMR: selection of individual 13C-13C dipolar interactions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 204:314-326. [PMID: 20392659 DOI: 10.1016/j.jmr.2010.03.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 03/10/2010] [Accepted: 03/18/2010] [Indexed: 05/29/2023]
Abstract
Herein is described a useful approach in solid-state NMR, for selecting homonuclear (13)C-(13)C spin pairs in a multiple-(13)C homonuclear dipolar coupled spin system. This method builds upon the zero-quantum (ZQ) dipolar recoupling method introduced by Levitt and coworkers (Marin-Montesinos et al., 2006) by extending the originally introduced one-dimensional (1D) experiment into a two-dimensional (2D) method with selective irradiation scheme, while moving the (13)C-(13)C mixing scheme from the transverse to the longitudinal mode, together with a dramatic improvement in the proton decoupling efficiency. Selective spin-pair recoupling experiments incorporating Gaussian and cosine-modulated Gaussian pulses for inverting specific spins were performed, demonstrating the ability to detect informative, simplified/individualized, long-range (13)C-(13)C homonuclear dipolar coupling interactions more accurately by removing less informative, stronger, short-range (13)C-(13)C interactions from 2D correlation spectra. The capability of this new approach was demonstrated experimentally on uniformly (13)C-labeled Glutamine and a tripeptide sample, GAL.
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Affiliation(s)
- Justin Spano
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, USA
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15
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Pandey MK, Ramachandran R. A theoretical perspective on the accuracy of rotational resonance (R2)-based distance measurements in solid-state NMR. Mol Phys 2010. [DOI: 10.1080/00268971003645347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Ladizhansky V. Homonuclear dipolar recoupling techniques for structure determination in uniformly 13C-labeled proteins. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 36:119-128. [PMID: 19729285 DOI: 10.1016/j.ssnmr.2009.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 07/21/2009] [Indexed: 05/28/2023]
Abstract
In solid-state NMR magic angle spinning is often used to remove line broadening associated with anisotropic interactions, such as chemical shift anisotropy and dipolar couplings. Dipolar recoupling refers to sequences of pulses designed to reintroduce dipolar interactions that are otherwise averaged by magic angle spinning. One of the key applications of homonuclear (and heteronuclear) dipolar recoupling is for the purpose of protein structure determination. Recoupling experiments, originally designed for applications in spin-pair labeled samples, have been revised in recent years for applications in samples with extensive or uniform incorporation of isotopic labels. In these samples multiple internuclear distances can in principle be probed simultaneously, but the dipolar truncation effects (i.e. attenuation of the effects of weak couplings by strong ones) circumvent such measurements. In this article we review some of the recent developments in homonuclear recoupling methods that allow overcoming this problem.
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Affiliation(s)
- Vladimir Ladizhansky
- Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada.
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van der Wel PCA, Eddy MT, Ramachandran R, Griffin RG. Targeted 13C-13C distance measurements in a microcrystalline protein via J-decoupled rotational resonance width measurements. Chemphyschem 2009; 10:1656-63. [PMID: 19565580 DOI: 10.1002/cphc.200900102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Rotational resonance width (R(2)W) magic-angle spinning (MAS) NMR experiments are performed to measure (13)C-(13)C distances in the hydrophobic core of the microcrystalline model protein G(Beta1). Such inter-residue distances are of particular value in NMR structure determinations. The experiments are done at a Larmor frequency of 750 MHz (1)H where the contribution of (13)C chemical shift anisotropy (CSA) to the R(2) transfer mechanism is significant. To minimize line broadening in the 2D spectra, we employ a combination of even/odd isotopic labeling with [1,3-(13)C] glycerol, and J-decoupling in the indirect dimension. This results in high-precision distance measurements between aromatic side chains of three tyrosine residues and distant methyl groups in the hydrophobic core of the protein. Even in the absence of information on the relative orientation of the shift tensors, we obtain relatively high precision data, which can be further improved by additional constraints on the tensor orientations.
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Affiliation(s)
- Patrick C A van der Wel
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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18
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Barnes AB, Andreas LB, Huber M, Ramachandran R, van der Wel PC, Veshtort M, Griffin RG, Mehta MA. High-resolution solid-state NMR structure of alanyl-prolyl-glycine. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:95-100. [PMID: 19596601 PMCID: PMC4133121 DOI: 10.1016/j.jmr.2009.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2009] [Revised: 06/05/2009] [Accepted: 06/10/2009] [Indexed: 05/21/2023]
Abstract
We present a de novo high-resolution structure of the peptide Alanyl-Prolyl-Glycine using a combination of sensitive solid-state NMR techniques that each yield precise structural constraints. High-quality (13)C-(13)C distance constraints are extracted by fitting rotational resonance width (R(2)W) experiments using Multimode Multipole Floquet Theory and experimental chemical shift anisotropy (CSA) orientations. In this strategy, a structure is first calculated using DANTE-REDOR and torsion angle measurements and the resulting relative CSA orientations are used as an input parameter in the (13)C-(13)C distance calculations. Finally, a refined structure is calculated using all the constraints. We investigate the effect of different structural constraints on structure quality, as determined by comparison to the crystal structure and also self-consistency of the calculated structures. Inclusion of all or subsets of these constraints into CNS calculations resulted in high-quality structures (0.02A backbone RMSD using all 11 constraints).
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Affiliation(s)
- Alexander B. Barnes
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
| | - Loren B. Andreas
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
- Department of Chemistry, Oberlin College, 119 Woodland Street, Oberlin, OH 44074, USA
| | - Matthias Huber
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
- ETH Zurich, Physical Chemistry, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
| | - Ramesh Ramachandran
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
- Indian Institute of Science Education Research (IISER), Mohali, Chandigarh, India
| | - Patrick C.A. van der Wel
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
- University of Pittsburgh, Department of Structural Biology, Pittsburgh, PA 15260, USA
| | - Mikhail Veshtort
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
| | - Robert G. Griffin
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts, Institute of Technology, Cambridge, MA 02139, USA
| | - Manish A. Mehta
- Department of Chemistry, Oberlin College, 119 Woodland Street, Oberlin, OH 44074, USA
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19
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Bayro MJ, Huber M, Ramachandran R, Davenport TC, Meier BH, Ernst M, Griffin RG. Dipolar truncation in magic-angle spinning NMR recoupling experiments. J Chem Phys 2009; 130:114506. [PMID: 19317544 DOI: 10.1063/1.3089370] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Quantitative solid-state NMR distance measurements in strongly coupled spin systems are often complicated due to the simultaneous presence of multiple noncommuting spin interactions. In the case of zeroth-order homonuclear dipolar recoupling experiments, the recoupled dipolar interaction between distant spins is attenuated by the presence of stronger couplings to nearby spins, an effect known as dipolar truncation. In this article, we quantitatively investigate the effect of dipolar truncation on the polarization-transfer efficiency of various homonuclear recoupling experiments with analytical theory, numerical simulations, and experiments. In particular, using selectively (13)C-labeled tripeptides, we compare the extent of dipolar truncation in model three-spin systems encountered in protein samples produced with uniform and alternating labeling. Our observations indicate that while the extent of dipolar truncation decreases in the absence of directly bonded nuclei, two-bond dipolar couplings can generate significant dipolar truncation of small, long-range couplings. Therefore, while alternating labeling alleviates the effects of dipolar truncation, and thus facilitates the application of recoupling experiments to large spin systems, it does not represent a complete solution to this outstanding problem.
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Affiliation(s)
- Marvin J Bayro
- Department of Chemistry, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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20
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De Paëpe G, Lewandowski JR, Loquet A, Böckmann A, Griffin RG. Proton assisted recoupling and protein structure determination. J Chem Phys 2008; 129:245101. [PMID: 19123534 PMCID: PMC2755343 DOI: 10.1063/1.3036928] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 11/03/2008] [Indexed: 11/14/2022] Open
Abstract
We introduce a homonuclear version of third spin assisted recoupling, a second-order mechanism that can be used for polarization transfer between (13)C or (15)N spins in magic angle spinning (MAS) NMR experiments, particularly at high spinning frequencies employed in contemporary high field MAS experiments. The resulting sequence, which we refer to as proton assisted recoupling (PAR), relies on a cross-term between (1)H-(13)C (or (1)H-(15)N) couplings to mediate zero quantum (13)C-(13)C (or (15)N-(15)N recoupling). In particular, using average Hamiltonian theory we derive an effective Hamiltonian for PAR and show that the transfer is mediated by trilinear terms of the form C(1) (+/-)C(2) (-/+)H(Z) for (13)C-(13)C recoupling experiments (or N(1) (+/-)N(2) (-/+)H(Z) for (15)N-(15)N). We use analytical and numerical simulations to explain the structure of the PAR optimization maps and to delineate the PAR matching conditions. We also detail the PAR polarization transfer dependence with respect to the local molecular geometry and explain the observed reduction in dipolar truncation. Finally, we demonstrate the utility of PAR in structural studies of proteins with (13)C-(13)C spectra of uniformly (13)C, (15)N labeled microcrystalline Crh, a 85 amino acid model protein that forms a domain swapped dimer (MW=2 x 10.4 kDa). The spectra, which were acquired at high MAS frequencies (omega(r)2pi>20 kHz) and magnetic fields (750-900 MHz (1)H frequencies) using moderate rf fields, exhibit numerous cross peaks corresponding to long (up to 6-7 A) (13)C-(13)C distances which are particularly useful in protein structure determination. Using results from PAR spectra we calculate the structure of the Crh protein.
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Affiliation(s)
- Gaël De Paëpe
- Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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21
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Peng X, Libich D, Janik R, Harauz G, Ladizhansky V. Dipolar Chemical Shift Correlation Spectroscopy for Homonuclear Carbon Distance Measurements in Proteins in the Solid State: Application to Structure Determination and Refinement. J Am Chem Soc 2007; 130:359-69. [DOI: 10.1021/ja076658v] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaohu Peng
- Department of Physics, Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1
| | - David Libich
- Department of Physics, Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1
| | - Rafal Janik
- Department of Physics, Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1
| | - George Harauz
- Department of Physics, Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1
| | - Vladimir Ladizhansky
- Department of Physics, Department of Molecular and Cellular Biology, and Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada, N1G 2W1
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22
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Janik R, Peng X, Ladizhansky V. (13)C-(13)C distance measurements in U-(13)C, (15)N-labeled peptides using rotational resonance width experiment with a homogeneously broadened matching condition. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 188:129-40. [PMID: 17644014 DOI: 10.1016/j.jmr.2007.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 06/06/2007] [Accepted: 06/06/2007] [Indexed: 05/16/2023]
Abstract
In this publication, we introduce a version of the rotational resonance width experiment with a homogeneously broadened matching condition. The increase in the bandwidth is achieved by the reduction of the proton decoupling power during mixing, which results in the reduction of zero-quantum relaxation, and broadens the rotational resonance condition. We show that one can achieve recoupling of the carbonyl-aliphatic side chain dipolar interactions band selectively, while avoiding the recoupling of strongly interacting C'-Calpha and C'-Cbeta spin pairs. The attenuation of the multi-spin effects in the presence of short zero-quantum relaxation enables a two-spin approximation to be employed for the analysis of the experimental data. The systematic error introduced by this approximation is estimated by comparing the results with a three-spin simulation. The experiment is demonstrated in [U-(13)C,(15)N]N-acetyl-L-Val-L-Leu dipeptide, where 11 distances, ranging from 2.5 to 6 A, were measured.
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Affiliation(s)
- Rafal Janik
- Department of Physics and Biophysics, Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1
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23
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Ramachandran R, Griffin RG. Description of depolarization effects in double-quantum solid state nuclear magnetic resonance experiments using multipole-multimode Floquet theory. J Chem Phys 2007; 125:44510. [PMID: 16942159 DOI: 10.1063/1.2216711] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Using an analytical model based on multipole-multimode Floquet theory (MMFT), we describe the polarization loss (or depolarization) observed in double-quantum (DQ) dipolar recoupling magic angle spinning (MAS) experiments. Specifically, the factors responsible for depolarization are analyzed in terms of higher order corrections to the spin Hamiltonian in addition to the usual phenomenological decay rate constant. From the MMFT model and the effective Hamiltonians, we elucidate the rationale behind the inclusion of a phenomenological damping term in DQ recoupling experiments. As a test of this theoretical approach, the recoupling efficiency of one class of (13)C-(13)C and (13)C-(15)N resonance width dipolar recoupling experiments are investigated at different magnetic field strengths and compared with the more exact numerical simulations. In contrast to existing analytical treatments, the role of higher order corrections is clearly explained in the context of the MMFT approach leading to a better understanding of the underlying spin physics. Furthermore, the analytical model presented herein provides a general framework for describing coherent and incoherent effects in homonuclear and heteronuclear DQ MAS recoupling experiments.
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Affiliation(s)
- Ramesh Ramachandran
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Ramachandran R, Lewandowski JR, van der Wel PCA, Griffin RG. Multipole-multimode Floquet theory of rotational resonance width experiments: C13–C13 distance measurements in uniformly labeled solids. J Chem Phys 2006; 124:214107. [PMID: 16774398 DOI: 10.1063/1.2194905] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A formal description of zero-quantum (ZQ) NMR processes using multipole-multimode Floquet theory is proposed for studying polarization transfer in magic angle spinning experiments. Specifically, we investigate the factors affecting the accuracy and precision of 13C-13C distance measurements that are based on ZQ-magnetization exchange processes in rotational resonance width experiments. With suitable examples drawn from measurements in N-acetyl-[U-13C,15N]-L-valine-L-leucine, we substantiate our approach and propose methods for improving the accuracy and reliability of such 13C-13C distance measurements in uniformly 13C, 15N-labeled solids. In addition, the theoretical model presented in this article provides a more general framework for describing relaxation phenomena involving multiple decay rate constants in zero-quantum processes.
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Affiliation(s)
- Ramesh Ramachandran
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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25
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Todokoro Y, Yumen I, Fukushima K, Kang SW, Park JS, Kohno T, Wakamatsu K, Akutsu H, Fujiwara T. Structure of tightly membrane-bound mastoparan-X, a G-protein-activating peptide, determined by solid-state NMR. Biophys J 2006; 91:1368-79. [PMID: 16714348 PMCID: PMC1518647 DOI: 10.1529/biophysj.106.082735] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The structure of mastoparan-X (MP-X), a G-protein activating peptide from wasp venom, in the state tightly bound to anionic phospholipid bilayers was determined by solid-state NMR spectroscopy. Carbon-13 and nitrogen-15 NMR signals of uniformly labeled MP-X were completely assigned by multidimensional intraresidue C-C, N-CalphaCbeta, and N-Calpha-C', and interresidue Calpha-CalphaCbeta, N-CalphaCbeta, and N-C'-Calpha correlation experiments. The backbone torsion angles were predicted from the chemical shifts of 13C', 13Calpha, 13Cbeta, and 15N signals with the aid of protein NMR database programs. In addition, two 13C-13C and three 13C-15N distances between backbone nuclei were precisely measured by rotational resonance and REDOR experiments, respectively. The backbone structure of MP-X was determined from the 26 dihedral angle restraints and five distances with an average root-mean-square deviation of 0.6 A. Peptide MP-X in the bilayer-bound state formed an amphiphilic alpha-helix for residues Trp3-Leu14 and adopted an extended conformation for Asn2. This membrane-bound conformation is discussed in relation to the peptide's activities to form pores in membranes and to activate G-proteins. This study demonstrates the power of multidimensional solid-state NMR of uniformly isotope-labeled molecules and distance measurements for determining the structures of peptides bound to lipid membranes.
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Affiliation(s)
- Yasuto Todokoro
- Institute for Protein Research, Osaka University, Suita, Japan
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26
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Magusin PCMM, Zorin VE, Aerts A, Houssin CJY, Yakovlev AL, Kirschhock CEA, Martens JA, van Santen RA. Template-Aluminosilicate Structures at the Early Stages of Zeolite ZSM-5 Formation. A Combined Preparative, Solid-state NMR, and Computational Study. J Phys Chem B 2005; 109:22767-74. [PMID: 16853966 DOI: 10.1021/jp053217u] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Species at three stages in the self-assembly of zeolite ZSM-5 have been studied with one- and two-dimensional magic-angle-spinning 13C, 27Al, 29Si, and 1H NMR spectroscopy and compared with the earlier proposed structures: (1) precursor species containing 33-36 T sites around a tetrapropylammonium (TPA) cation, (2) nanoslabs consisting of a flat 4 x 3 array of such precursors, and (3) the final TPA-ZSM-5 zeolite. Synthesis was carried out in D2O to suppress the water and silanol protons. Under such conditions, the effective Si-H and Al-H distances measured with 29Si-{1H} and 27Al-{1H} rotational echo double resonance (REDOR) reflect the interactions between TPA cations and the surrounding aluminosilica. The 29Si-{1H} REDOR curves for Q4-type silicon atoms at the three mentioned stages are closely similar, as well as the observed 27Al-1H REDOR curve for the precursor species compared to that for the TPA-ZSM-5. This indicates that in addition to externally attached TPA, there is also internal TPA already incorporated at an early stage into the aluminosilicate in a similar way as in the final zeolite, in accordance with the earlier proposed MFI self-assembly pathway (Kirschhock et al. Angew. Chem. Int. Ed. 2001, 40, 2637). However, the effective distances extracted from the initial REDOR curvatures are significantly (10-15%) larger than those computed for the model. Since there is no temperature effect, we tentatively assign this difference to a reduction of the 29Si-1H and 27Al-1H interactions by multispin decoherence effects or self-decoupling caused by proton spin diffusion. By assuming the computed model distances and fitting Anderson-Weiss curves to the observed REDOR data, we obtain similar "decoherence times" in the order of 0.1 ms. The observed 29Si-{1H} REDOR dephasing for the Q3 sites in the precursors is significantly faster than that for the Q4 sites. This is tentatively ascribed to a partial deuteron-proton back exchange at the silanol positions.
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Affiliation(s)
- Pieter C M M Magusin
- Schuit Institute of Catalysis, Eindhoven University of Technology, The Netherlands.
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Ladizhansky V, Griffin RG. Band-selective carbonyl to aliphatic side chain 13C-13C distance measurements in U-13C,15N-labeled solid peptides by magic angle spinning NMR. J Am Chem Soc 2004; 126:948-58. [PMID: 14733572 DOI: 10.1021/ja037138c] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe three-dimensional magic angle spinning NMR experiments that enable simultaneous band-selective measurement of the multiple distance constraints between carbonyl and side chain carbons in uniformly 13C,15N-labeled peptides. The approaches are designed to circumvent the dipolar truncation and to allow experimental separation of the multiple quantum (MQ) relaxation and dipolar effects. The pulse sequences employ the double quantum (DQ) rotational resonance in the tilted frame (R2TR) to perform selective polarization transfers that reintroduce the 13C'-13Cgamma,delta dipolar interactions. The scheme avoids recoupling of the strongly coupled C'-Calpha and C'-Cbeta spin pairs, therefore minimizing dipolar truncation effects. The experiment is performed in a constant time fashion as a function of the radio frequency irradiation intensity and measures the line shape of the DQ transition. The width and the intensity of this line shape are analyzed in terms of the DQ relaxation and dipolar coupling. The attenuation of the multispin effects in the presence of relaxation enables a two-spin approximation to be employed for the analysis of the experimental data. The systematic error introduced by this approximation is estimated by comparing the results with a three-spin simulation. The contributions of B1-inhomogeneity, CSA orientation effects, and the effects of inhomogeneous line broadening are also estimated. The experiments are demonstrated in model U-13C,15N-labeled peptides, N-acetyl-L-Val-L-Leu and N-formyl-L-Met-L-Leu-L-Phe, where 10 and 6 distances, ranging between 3 and 6 A, were measured, respectively.
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Affiliation(s)
- Vladimir Ladizhansky
- Department of Chemistry and Center for Magnetic Resonance, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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Sonnenberg L, Luca S, Baldus M. Multiple-spin analysis of chemical-shift-selective (13C, 13C) transfer in uniformly labeled biomolecules. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 166:100-110. [PMID: 14675825 DOI: 10.1016/j.jmr.2003.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Chemical-shift-selective (13C, 13C) polarization transfer is analyzed in uniformly labeled biomolecules. It is shown that the spin system dynamics remain sensitive to the distance of interest and can be well reproduced within a quantum-mechanical multiple-spin analysis. These results lead to a general approach on how to describe chemical-shift-selective transfer in uniformly labeled systems. As demonstrated in the case of ubiquitin, this methodology can be used to detect long-range distance constraints in uniformly labeled proteins.
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Affiliation(s)
- Lars Sonnenberg
- Department for NMR-Based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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Ramachandran R, Ladizhansky V, Bajaj VS, Griffin RG. 13C−13C Rotational Resonance Width Distance Measurements in Uniformly 13C-Labeled Peptides. J Am Chem Soc 2003; 125:15623-9. [PMID: 14664610 DOI: 10.1021/ja037761x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rotational resonance width (R2W) experiment is a constant-time version of the rotational resonance (R2) experiment, in which the magnetization exchange is measured as a function of sample spinning frequency rather than the mixing time. The significant advantage of this experiment over conventional R2 is that both the dipolar coupling and the relaxation parameters can be independently and unambiguously extracted from the magnetization exchange profile. In this paper, we combine R2W with two-dimensional 13C-13C chemical shift correlation spectroscopy and demonstrate the utility of this technique for the site-specific measurement of multiple 13C-13C distances in uniformly labeled solids. The dipolar truncation effects, usually associated with distance measurements in uniformly labeled solids, are considerably attenuated in R2W experiments. Thus, R2W experiments are applicable to uniformly labeled biological systems. To validate this statement, multiple 13C-13C distances (in the range of 3-6 A) were determined in N-acetyl-[U-13C,15N]l-Val-l-Leu with an average precision of +/-0.5 A. Furthermore, the distance constraints extracted using a two-spin model agree well with the X-ray crystallographic data.
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Affiliation(s)
- Ramesh Ramachandran
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139-4307, USA
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