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Porat G, Lusky OS, Dayan N, Goldbourt A. Nonuniformly sampled exclusively- 13 C/ 15 N 4D solid-state NMR experiments: Assignment and characterization of IKe phage capsid. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2021; 59:237-246. [PMID: 32603513 DOI: 10.1002/mrc.5072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/11/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
An important step in the process of protein research by NMR is the assignment of chemical shifts. In the coat protein of IKe bacteriophage, there are 53 residues making up a long helix resulting in relatively high spectral ambiguity. Assignment thus requires the collection of a set of three-dimensional (3D) experiments and the preparation of sparsely labeled samples. Increasing the dimensionality can facilitate fast and reliable assignment of IKe and of larger proteins. Recent progress in nonuniform sampling techniques made the application of multidimensional NMR solid-state experiments beyond 3D more practical. 4D 1 H-detected experiments have been demonstrated in high-fields and at spinning speeds of 60 kHz and higher but are not practical at spinning speeds of 10-20 kHz for fully protonated proteins. Here, we demonstrate the applicability of a nonuniformly sampled 4D 13 C/15 N-only correlation experiment performed at a moderate field of 14.1 T, which can incorporate sufficiently long acquisition periods in all dimensions. We show how a single CANCOCX experiment, supported by several 2D carbon-based correlation experiments, is utilized for the assignment of heteronuclei in the coat protein of the IKe bacteriophage. One sparsely labeled sample was used to validate sidechain assignment of several hydrophobic-residue sidechains. A comparison to solution NMR studies of isolated IKe coat proteins embedded in micelles points to key residues involved in structural rearrangement of the capsid upon assembly of the virus. The benefits of 4D to a quicker assignment are discussed, and the method may prove useful for studying proteins at relatively low fields.
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Affiliation(s)
- Gal Porat
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, 19716, USA
| | - Orr Simon Lusky
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Nir Dayan
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
- Schulich Faculty of Chemistry, Technion-Institute of Technology, Haifa, Israel
| | - Amir Goldbourt
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
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2
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Mukhopadhyay D, Gupta C, Theint T, Jaroniec CP. Peptide bond conformation in peptides and proteins probed by dipolar coupling-chemical shift tensor correlation solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 297:152-160. [PMID: 30396157 PMCID: PMC6289736 DOI: 10.1016/j.jmr.2018.10.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 05/30/2023]
Abstract
Multidimensional magic-angle spinning solid-state NMR experiments are described that permit cis and trans peptide bonds in uniformly 13C,15N-labeled peptides and proteins to be unambiguously distinguished in residue-specific manner by determining the relative orientations of the amide 13C' CSA and 1H-15N dipolar coupling tensors. The experiments are demonstrated for model peptides glycylglycine and 2,5-diketopiperazine containing trans and cis peptide bonds, respectively. Subsequently, the measurements are extended to two representative proteins that contain exclusively trans peptide bonds, microcrystalline B3 immunoglobulin domain of protein G and Y145Stop human prion protein amyloid fibrils, to illustrate their applicability to a wide range of protein systems.
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Affiliation(s)
- Dwaipayan Mukhopadhyay
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States
| | - Chitrak Gupta
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States
| | - Theint Theint
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States
| | - Christopher P Jaroniec
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States.
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3
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Petrović D, Wang X, Strodel B. How accurately do force fields represent protein side chain ensembles? Proteins 2018; 86:935-944. [DOI: 10.1002/prot.25525] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 05/02/2018] [Accepted: 05/14/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Dušan Petrović
- Institute of Complex Systems, Structural Biochemistry, Forschungszentrum Jülich; Jülich, 52425 Germany
- Department of Cell and Molecular Biology; Uppsala University, BMC Box 596; Uppsala, 751 24 Sweden
| | - Xue Wang
- Institute of Complex Systems, Structural Biochemistry, Forschungszentrum Jülich; Jülich, 52425 Germany
- Institute of Theoretical and Computational Chemistry; Heinrich Heine University Düsseldorf, Universitätsstraße 1; Düsseldorf, 40225 Germany
| | - Birgit Strodel
- Institute of Complex Systems, Structural Biochemistry, Forschungszentrum Jülich; Jülich, 52425 Germany
- Institute of Theoretical and Computational Chemistry; Heinrich Heine University Düsseldorf, Universitätsstraße 1; Düsseldorf, 40225 Germany
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4
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Knight MJ, Felli IC, Pierattelli R, Emsley L, Pintacuda G. Magic angle spinning NMR of paramagnetic proteins. Acc Chem Res 2013; 46:2108-16. [PMID: 23506094 DOI: 10.1021/ar300349y] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Metal ions are ubiquitous in biochemical and cellular processes. Since many metal ions are paramagnetic due to the presence of unpaired electrons, paramagnetic molecules are an important class of targets for research in structural biology and related fields. Today, NMR spectroscopy plays a central role in the investigation of the structure and chemical properties of paramagnetic metalloproteins, linking the observed paramagnetic phenomena directly to electronic and molecular structure. A major step forward in the study of proteins by solid-state NMR came with the advent of ultrafast magic angle spinning (MAS) and the ability to use (1)H detection. Combined, these techniques have allowed investigators to observe nuclei that previously were invisible in highly paramagnetic metalloproteins. In addition, these techniques have enabled quantitative site-specific measurement of a variety of long-range paramagnetic effects. Instead of limiting solid-state NMR studies of biological systems, paramagnetism provides an information-rich phenomenon that can be exploited in these studies. This Account emphasizes state-of-the-art methods and applications of solid-state NMR in paramagnetic systems in biological chemistry. In particular, we discuss the use of ultrafast MAS and (1)H-detection in perdeuterated paramagnetic metalloproteins. Current methodology allows us to determine the structure and dynamics of metalloenzymes, and, as an example, we describe solid-state NMR studies of microcrystalline superoxide dismutase, a 32 kDa dimer. Data were acquired with remarkably short times, and these experiments required only a few milligrams of sample.
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Affiliation(s)
- Michael J. Knight
- Université de Lyon, Institut de Sciences Analytiques (CNRS / ENS-Lyon / UCB Lyon 1), Centre de RMN à Très Hauts Champs, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Isabella C. Felli
- Department of Chemistry “Ugo Schiff“ and Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6 − 50019 Sesto Fiorentino, FI, Italy
| | - Roberta Pierattelli
- Department of Chemistry “Ugo Schiff“ and Magnetic Resonance Center (CERM), University of Florence, via Luigi Sacconi 6 − 50019 Sesto Fiorentino, FI, Italy
| | - Lyndon Emsley
- Université de Lyon, Institut de Sciences Analytiques (CNRS / ENS-Lyon / UCB Lyon 1), Centre de RMN à Très Hauts Champs, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Guido Pintacuda
- Université de Lyon, Institut de Sciences Analytiques (CNRS / ENS-Lyon / UCB Lyon 1), Centre de RMN à Très Hauts Champs, 5 rue de la Doua, 69100 Villeurbanne, France
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5
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Siriwardana K, Wang A, Vangala K, Fitzkee N, Zhang D. Probing the effects of cysteine residues on protein adsorption onto gold nanoparticles using wild-type and mutated GB3 proteins. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10990-10996. [PMID: 23927741 DOI: 10.1021/la402239h] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The role of cysteine residues in the protein binding kinetics and stability on gold nanoparticles (AuNP) was studied using AuNP localized surface plasmon resonance (LSPR) in combination with an organothiol (OT) displacement method. GB3, the third IgG-binding domain of protein G, was used to model protein-AuNP adsorption. While wild-type GB3 (GB30) contains no cysteine residues, bioengineered GB3 variants containing one (GB31) and two (GB32) cysteine residues were also tested. The cysteine content has no significant effect on GB3 binding kinetics with AuNPs, and most protein adsorption occurs within the first few seconds upon protein/AuNP mixing. However, the stability of GB3 on the AuNP surface against OT displacement depends strongly on the cysteine content and the age of the AuNP/GB3 mixture. The GB30 covered AuNPs can be completely destabilized and aggregated by OTs, regardless of the age of the GB30/AuNP mixtures. Long-time incubation of GB31 or GB32 with AuNPs can stabilize AuNPs against the OT adsorption inducted aggregation. This study indicates that multiple forces involved in the GB3/AuNP interaction, and covalent binding between cysteine and AuNP is essential for a stable protein/AuNP complex.
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Affiliation(s)
- Kumudu Siriwardana
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi 39762, USA
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Helmus JJ, Jaroniec CP. Nmrglue: an open source Python package for the analysis of multidimensional NMR data. JOURNAL OF BIOMOLECULAR NMR 2013; 55:355-67. [PMID: 23456039 PMCID: PMC3636164 DOI: 10.1007/s10858-013-9718-x] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 02/19/2013] [Indexed: 05/04/2023]
Abstract
Nmrglue, an open source Python package for working with multidimensional NMR data, is described. When used in combination with other Python scientific libraries, nmrglue provides a highly flexible and robust environment for spectral processing, analysis and visualization and includes a number of common utilities such as linear prediction, peak picking and lineshape fitting. The package also enables existing NMR software programs to be readily tied together, currently facilitating the reading, writing and conversion of data stored in Bruker, Agilent/Varian, NMRPipe, Sparky, SIMPSON, and Rowland NMR Toolkit file formats. In addition to standard applications, the versatility offered by nmrglue makes the package particularly suitable for tasks that include manipulating raw spectrometer data files, automated quantitative analysis of multidimensional NMR spectra with irregular lineshapes such as those frequently encountered in the context of biomacromolecular solid-state NMR, and rapid implementation and development of unconventional data processing methods such as covariance NMR and other non-Fourier approaches. Detailed documentation, install files and source code for nmrglue are freely available at http://nmrglue.com. The source code can be redistributed and modified under the New BSD license.
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7
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Lakomek NA, Ying J, Bax A. Measurement of ¹⁵N relaxation rates in perdeuterated proteins by TROSY-based methods. JOURNAL OF BIOMOLECULAR NMR 2012; 53:209-21. [PMID: 22689066 PMCID: PMC3412688 DOI: 10.1007/s10858-012-9626-5] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 04/04/2012] [Indexed: 05/11/2023]
Abstract
While extracting dynamics parameters from backbone (15)N relaxation measurements in proteins has become routine over the past two decades, it is increasingly recognized that accurate quantitative analysis can remain limited by the potential presence of systematic errors associated with the measurement of (15)N R(1) and R(2) or R(1ρ) relaxation rates as well as heteronuclear (15)N-{(1)H} NOE values. We show that systematic errors in such measurements can be far larger than the statistical error derived from either the observed signal-to-noise ratio, or from the reproducibility of the measurement. Unless special precautions are taken, the problem of systematic errors is shown to be particularly acute in perdeuterated systems, and even more so when TROSY instead of HSQC elements are used to read out the (15)N magnetization through the NMR-sensitive (1)H nucleus. A discussion of the most common sources of systematic errors is presented, as well as TROSY-based pulse schemes that appear free of systematic errors to the level of <1 %. Application to the small perdeuterated protein GB3, which yields exceptionally high S/N and therefore is an ideal test molecule for detection of systematic errors, yields relaxation rates that show considerably less residue by residue variation than previous measurements. Measured R(2)'/R(1)' ratios fit an axially symmetric diffusion tensor with a Pearson's correlation coefficient of 0.97, comparable to fits obtained for backbone amide RDCs to the Saupe matrix.
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Affiliation(s)
| | | | - Ad Bax
- Correspondence: Ad Bax, National Institutes of Health, DHHS NIDDK LCP, Building 5, Room 126, 9000 Rockville Pike, Bethesda, MD 20892-0520, Tel.:301-496-2848, Fax: 301-402-0907,
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8
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Jones EM, Wu B, Surewicz K, Nadaud PS, Helmus JJ, Chen S, Jaroniec CP, Surewicz WK. Structural polymorphism in amyloids: new insights from studies with Y145Stop prion protein fibrils. J Biol Chem 2011; 286:42777-42784. [PMID: 22002245 PMCID: PMC3234922 DOI: 10.1074/jbc.m111.302539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/05/2011] [Indexed: 11/06/2022] Open
Abstract
The C-terminally-truncated human prion protein variant Y145Stop (or PrP23-144), associated with a familial prion disease, provides a valuable model for studying the fundamental properties of protein amyloids. In previous solid-state NMR experiments, we established that the β-sheet core of the PrP23-144 amyloid is composed of two β-strand regions encompassing residues ∼113-125 and ∼130-140. The former segment contains a highly conserved hydrophobic palindrome sequence, (113)AGAAAAGA(120), which has been considered essential to PrP conformational conversion. Here, we examine the role of this segment in fibrillization of PrP23-144 using a deletion variant, Δ113-120 PrP23-144, in which the palindrome sequence is missing. Surprisingly, we find that deletion of the palindrome sequence affects neither the amyloidogenicity nor the polymerization kinetics of PrP23-144, although it does alter amyloid conformation and morphology. Using two-dimensional and three-dimensional solid-state NMR methods, we find that Δ113-120 PrP23-144 fibrils contain an altered β-core extended N-terminally to residue ∼106, encompassing residues not present in the core of wild-type PrP23-144 fibrils. The C-terminal β-strand of the core, however, is similar in both fibril types. Collectively, these data indicate that amyloid cores of PrP23-144 variants contain "essential" (i.e. nucleation-determining) and "nonessential" regions, with the latter being "movable" in amino acid sequence space. These findings reveal an intriguing new mechanism for structural polymorphism in amyloids and suggest a potential means for modulating the physicochemical properties of amyloid fibrils without compromising their polymerization characteristics.
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Affiliation(s)
- Eric M Jones
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Bo Wu
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Krystyna Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Philippe S Nadaud
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Jonathan J Helmus
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Shugui Chen
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | | | - Witold K Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106.
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9
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Abramov G, Morag O, Goldbourt A. Magic-Angle Spinning NMR of a Class I Filamentous Bacteriophage Virus. J Phys Chem B 2011; 115:9671-80. [DOI: 10.1021/jp2040955] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gili Abramov
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Omry Morag
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
| | - Amir Goldbourt
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv 69978, Tel Aviv, Israel
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10
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Cai L, Kosov DS, Fushman D. Density functional calculations of backbone 15N shielding tensors in beta-sheet and turn residues of protein G. JOURNAL OF BIOMOLECULAR NMR 2011; 50:19-33. [PMID: 21305337 PMCID: PMC3085593 DOI: 10.1007/s10858-011-9474-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 01/18/2011] [Indexed: 05/30/2023]
Abstract
We performed density functional calculations of backbone (15)N shielding tensors in the regions of beta-sheet and turns of protein G. The calculations were carried out for all twenty-four beta-sheet residues and eight beta-turn residues in the protein GB3 and the results were compared with the available experimental data from solid-state and solution NMR measurements. Together with the alpha-helix data, our calculations cover 39 out of the 55 residues (or 71%) in GB3. The applicability of several computational models developed previously (Cai et al. in J Biomol NMR 45:245-253, 2009) to compute (15)N shielding tensors of alpha-helical residues is assessed. We show that the proposed quantum chemical computational model is capable of predicting isotropic (15)N chemical shifts for an entire protein that are in good correlation with experimental data. However, the individual components of the predicted (15)N shielding tensor agree with experiment less well: the computed values show much larger spread than the experimental data, and there is a profound difference in the behavior of the tensor components for alpha-helix/turns and beta-sheet residues. We discuss possible reasons for this.
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Affiliation(s)
- Ling Cai
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
- Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Daniel S. Kosov
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
- Department of Physics and Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Campus Plaine, CP 231, Blvd du Triomphe, B-1050 Brussels, Belgium
| | - David Fushman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
- Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
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11
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Plevin MJ, Bryce DL, Boisbouvier J. Direct detection of CH/π interactions in proteins. Nat Chem 2010; 2:466-71. [DOI: 10.1038/nchem.650] [Citation(s) in RCA: 225] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 03/23/2010] [Indexed: 11/09/2022]
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12
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Janik R, Ritz E, Gravelle A, Shi L, Peng X, Ladizhansky V. Interresidue carbonyl-carbonyl polarization transfer experiments in uniformly 13C,15N-labeled peptides and proteins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 203:177-84. [PMID: 20060344 DOI: 10.1016/j.jmr.2009.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 12/16/2009] [Indexed: 05/04/2023]
Abstract
In this work, we demonstrate that Homonuclear Rotary Resonance Recoupling (HORROR) can be used to reintroduce carbonyl-carbonyl interresidue dipolar interactions and to achieve efficient polarization transfer between carbonyl atoms in uniformly (13)C,(15)N-labeled peptides and proteins. We show that the HORROR condition is anisotropically broadened and overall shifted to higher radio frequency intensities because of the CSA effects. These effects are analyzed theoretically using Average Hamiltonian Theory. At spinning frequencies used in this study, 22kHz, this broadening is experimentally found to be on the order of a kilohertz at a proton field of 600MHz. To match HORROR condition over all powder orientations, variable amplitude radio frequency (RF) fields are required, and efficient direct transfers on the order of 20-30% can be straightforwardly established. Two- and three-dimensional chemical shift correlation experiments establishing long-range interresidue connectivities (e.g., (N[i]-CO[i-2])) are demonstrated on the model peptide N-acetyl-valine-leucine, and on the third immunoglobulin binding domain of protein G. Possible future developments are discussed.
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Affiliation(s)
- Rafal Janik
- Department of Physics, University of Guelph, 50 Stone Road East, Guelph, Ont, Canada
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13
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Cai L, Fushman D, Kosov DS. Density functional calculations of chemical shielding of backbone 15N in helical residues of protein G. JOURNAL OF BIOMOLECULAR NMR 2009; 45:245-253. [PMID: 19644655 PMCID: PMC2884268 DOI: 10.1007/s10858-009-9358-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 07/09/2009] [Indexed: 05/28/2023]
Abstract
We performed density functional calculations of backbone (15)N chemical shielding tensors in selected helical residues of protein G. Here we describe a computationally efficient methodology to include most of the important effects in the calculation of chemical shieldings of backbone (15)N. We analyzed the role of long-range intra-protein electrostatic interactions by comparing models with different complexity in vacuum and in charge field. Our results show that the dipole moment of the alpha-helix can cause significant deshielding of (15)N; therefore, it needs to be considered when calculating (15)N chemical shielding. We found that it is important to include interactions with the side chains that are close in space when the charged form for ionizable side chains is adopted in the calculation. We also illustrate how the ionization state of these side chains can affect the chemical shielding tensor elements. Chemical shielding calculations using a 8-residue fragment model in vacuum and adopting the charged form of ionizable side chains yield a generally good agreement with experimental data.
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Affiliation(s)
- Ling Cai
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - David Fushman
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Daniel S. Kosov
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
- Department of Physics and Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, Campus Plaine, CP 231, Blvd du Triomphe, B-1050 Brussels, Belgium
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14
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Nadaud PS, Helmus JJ, Kall SL, Jaroniec CP. Paramagnetic Ions Enable Tuning of Nuclear Relaxation Rates and Provide Long-Range Structural Restraints in Solid-State NMR of Proteins. J Am Chem Soc 2009; 131:8108-20. [DOI: 10.1021/ja900224z] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Philippe S. Nadaud
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Jonathan J. Helmus
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
| | - Stefanie L. Kall
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
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15
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Shen Y, Vernon R, Baker D, Bax A. De novo protein structure generation from incomplete chemical shift assignments. JOURNAL OF BIOMOLECULAR NMR 2009; 43:63-78. [PMID: 19034676 PMCID: PMC2683404 DOI: 10.1007/s10858-008-9288-5] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Accepted: 10/28/2008] [Indexed: 05/19/2023]
Abstract
NMR chemical shifts provide important local structural information for proteins. Consistent structure generation from NMR chemical shift data has recently become feasible for proteins with sizes of up to 130 residues, and such structures are of a quality comparable to those obtained with the standard NMR protocol. This study investigates the influence of the completeness of chemical shift assignments on structures generated from chemical shifts. The Chemical-Shift-Rosetta (CS-Rosetta) protocol was used for de novo protein structure generation with various degrees of completeness of the chemical shift assignment, simulated by omission of entries in the experimental chemical shift data previously used for the initial demonstration of the CS-Rosetta approach. In addition, a new CS-Rosetta protocol is described that improves robustness of the method for proteins with missing or erroneous NMR chemical shift input data. This strategy, which uses traditional Rosetta for pre-filtering of the fragment selection process, is demonstrated for two paramagnetic proteins and also for two proteins with solid-state NMR chemical shift assignments.
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Affiliation(s)
- Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, USA
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16
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Helmus JJ, Nadaud PS, Höfer N, Jaroniec CP. Determination of methyl 13C-15N dipolar couplings in peptides and proteins by three-dimensional and four-dimensional magic-angle spinning solid-state NMR spectroscopy. J Chem Phys 2008; 128:052314. [PMID: 18266431 DOI: 10.1063/1.2817638] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We describe three- and four-dimensional semiconstant-time transferred echo double resonance (SCT-TEDOR) magic-angle spinning solid-state nuclear magnetic resonance (NMR) experiments for the simultaneous measurement of multiple long-range (15)N-(13)C(methyl) dipolar couplings in uniformly (13)C, (15)N-enriched peptides and proteins with high resolution and sensitivity. The methods take advantage of (13)C spin topologies characteristic of the side-chain methyl groups in amino acids alanine, isoleucine, leucine, methionine, threonine, and valine to encode up to three distinct frequencies ((15)N-(13)C(methyl) dipolar coupling, (15)N chemical shift, and (13)C(methyl) chemical shift) within a single SCT evolution period of initial duration approximately 1(1)J(CC) (where (1)J(CC) approximately 35 Hz, is the one-bond (13)C(methyl)-(13)C J-coupling) while concurrently suppressing the modulation of NMR coherences due to (13)C-(13)C and (15)N-(13)C J-couplings and transverse relaxation. The SCT-TEDOR schemes offer several important advantages over previous methods of this type. First, significant (approximately twofold to threefold) gains in experimental sensitivity can be realized for weak (15)N-(13)C(methyl) dipolar couplings (corresponding to structurally interesting, approximately 3.5 A or longer, distances) and typical (13)C(methyl) transverse relaxation rates. Second, the entire SCT evolution period can be used for (13)C(methyl) and/or (15)N frequency encoding, leading to increased spectral resolution with minimal additional coherence decay. Third, the experiments are inherently "methyl selective," which results in simplified NMR spectra and obviates the use of frequency-selective pulses or other spectral filtering techniques. Finally, the (15)N-(13)C cross-peak buildup trajectories are purely dipolar in nature (i.e., not influenced by J-couplings or relaxation), which enables the straightforward extraction of (15)N-(13)C(methyl) distances using an analytical model. The SCT-TEDOR experiments are demonstrated on a uniformly (13)C, (15)N-labeled peptide, N-acetyl-valine, and a 56 amino acid protein, B1 immunoglobulin-binding domain of protein G (GB1), where the measured (15)N-(13)C(methyl) dipolar couplings provide site-specific information about side-chain dihedral angles and the packing of protein molecules in the crystal lattice.
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Affiliation(s)
- Jonathan J Helmus
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA
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