1
|
Porat-Dahlerbruch G, Polenova T. Simultaneous recoupling of chemical shift tensors of two nuclei by R-symmetry sequences. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 348:107382. [PMID: 36716616 PMCID: PMC10023370 DOI: 10.1016/j.jmr.2023.107382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 05/18/2023]
Abstract
Chemical shift tensors (CSTs) are sensitive probes of structure and dynamics. R-symmetry pulse sequences (RNCSA) can efficiently recouple CSTs of varying magnitudes in magic angle spinning (MAS) NMR experiments, for a broad range of conditions and MAS frequencies. Herein, we introduce dual-channel R-symmetry pulse sequences for simultaneously recording CSTs of two different nuclei in a single experiment (DORNE-CSA). We demonstrate the performance of DORNE-CSA sequences for simultaneous measurement of 13C and 15N CSTs, on a U-13C,15N-labeled microcrystalline l-histidine. We show that the DORNE-CSA method is robust, provides accurate CST parameters, and takes only half of the measurement time compared to a pair of RNCSA experiments otherwise required for recording the CSTs of individual nuclei. DORNE-CSA approach is broadly applicable to a wide range of biological and inorganic systems.
Collapse
Affiliation(s)
- Gal Porat-Dahlerbruch
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Tatyana Polenova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States; Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, 1051 Biomedical Science Tower 3, 3501 Fifth Avenue, Pittsburgh, PA 15261, United States.
| |
Collapse
|
2
|
Ahlawat S, Mote KR, Lakomek NA, Agarwal V. Solid-State NMR: Methods for Biological Solids. Chem Rev 2022; 122:9643-9737. [PMID: 35238547 DOI: 10.1021/acs.chemrev.1c00852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In the last two decades, solid-state nuclear magnetic resonance (ssNMR) spectroscopy has transformed from a spectroscopic technique investigating small molecules and industrial polymers to a potent tool decrypting structure and underlying dynamics of complex biological systems, such as membrane proteins, fibrils, and assemblies, in near-physiological environments and temperatures. This transformation can be ascribed to improvements in hardware design, sample preparation, pulsed methods, isotope labeling strategies, resolution, and sensitivity. The fundamental engagement between nuclear spins and radio-frequency pulses in the presence of a strong static magnetic field is identical between solution and ssNMR, but the experimental procedures vastly differ because of the absence of molecular tumbling in solids. This review discusses routinely employed state-of-the-art static and MAS pulsed NMR methods relevant for biological samples with rotational correlation times exceeding 100's of nanoseconds. Recent developments in signal filtering approaches, proton methodologies, and multiple acquisition techniques to boost sensitivity and speed up data acquisition at fast MAS are also discussed. Several examples of protein structures (globular, membrane, fibrils, and assemblies) solved with ssNMR spectroscopy have been considered. We also discuss integrated approaches to structurally characterize challenging biological systems and some newly emanating subdisciplines in ssNMR spectroscopy.
Collapse
Affiliation(s)
- Sahil Ahlawat
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Kaustubh R Mote
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| | - Nils-Alexander Lakomek
- University of Düsseldorf, Institute for Physical Biology, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Vipin Agarwal
- Tata Institute of Fundamental Research Hyderabad, Survey No. 36/P Gopanpally, Serilingampally, Ranga Reddy District, Hyderabad 500046, Telangana, India
| |
Collapse
|
3
|
Kupče Ē, Yong JRJ, Widmalm G, Claridge TDW. Parallel NMR Supersequences: Ten Spectra in a Single Measurement. JACS AU 2021; 1:1892-1897. [PMID: 34841408 PMCID: PMC8611666 DOI: 10.1021/jacsau.1c00423] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Indexed: 05/05/2023]
Abstract
The principles employed in parallel NMR and MRI are applied to NMR supersequences yielding as many as ten 2D NMR spectra in one measurement. We present a number of examples where two NOAH (NMR by Ordered Acquisition using 1H-detection) supersequences are recorded in parallel, thus dramatically increasing the information content obtained in a single NMR experiment. The two parallel supersequences entangled by time-sharing schemes (IPAP-seHSQC, HSQC-COSY, and HSQC-TOCSY) incorporate also modified (sequential and/or interleaved) conventional pulse schemes (modules), including HMBC, TOCSY, COSY, CLIP-COSY, NOESY, and ROESY. Such parallel supersequences can be tailored for specific applications, for instance, the analysis and characterization of molecular structure of complex organic molecules from a single measurement. In particular, the CASPER software was used to establish the structure of a tetrasaccharide, β-LNnTOMe, with a high degree of confidence from a single measurement involving a parallel NOAH-5 supersequence.
Collapse
Affiliation(s)
- Ēriks Kupče
- Bruker
UK Ltd, R&D, Banner
Lane, Coventry CV4 9GH, United Kingdom
| | - Jonathan R. J. Yong
- Department
of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| | - Göran Widmalm
- Department
of Organic Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
| | - Tim D. W. Claridge
- Department
of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United
Kingdom
| |
Collapse
|
4
|
Kupče Ē, Mote KR, Webb A, Madhu PK, Claridge TDW. Multiplexing experiments in NMR and multi-nuclear MRI. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 124-125:1-56. [PMID: 34479710 DOI: 10.1016/j.pnmrs.2021.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 05/22/2023]
Abstract
Multiplexing NMR experiments by direct detection of multiple free induction decays (FIDs) in a single experiment offers a dramatic increase in the spectral information content and often yields significant improvement in sensitivity per unit time. Experiments with multi-FID detection have been designed with both homonuclear and multinuclear acquisition, and the advent of multiple receivers on commercial spectrometers opens up new possibilities for recording spectra from different nuclear species in parallel. Here we provide an extensive overview of such techniques, designed for applications in liquid- and solid-state NMR as well as in hyperpolarized samples. A brief overview of multinuclear MRI is also provided, to stimulate cross fertilization of ideas between the two areas of research (NMR and MRI). It is shown how such techniques enable the design of experiments that allow structure elucidation of small molecules from a single measurement. Likewise, in biomolecular NMR experiments multi-FID detection allows complete resonance assignment in proteins. Probes with multiple RF microcoils routed to multiple NMR receivers provide an alternative way of increasing the throughput of modern NMR systems, effectively reducing the cost of NMR analysis and increasing the information content at the same time. Solid-state NMR experiments have also benefited immensely from both parallel and sequential multi-FID detection in a variety of multi-dimensional pulse schemes. We are confident that multi-FID detection will become an essential component of future NMR methodologies, effectively increasing the sensitivity and information content of NMR measurements.
Collapse
Affiliation(s)
- Ēriks Kupče
- Bruker UK Ltd., Banner Lane, Coventry CV4 9GH, United Kingdom.
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research-Hyderabad, 36/P Gopanpally Village, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Andrew Webb
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, Netherlands
| | - Perunthiruthy K Madhu
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research-Hyderabad, 36/P Gopanpally Village, Ranga Reddy District, Hyderabad 500 046, Telangana, India
| | - Tim D W Claridge
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, UK
| |
Collapse
|
5
|
Stanek J, Schubeis T, Paluch P, Güntert P, Andreas LB, Pintacuda G. Automated Backbone NMR Resonance Assignment of Large Proteins Using Redundant Linking from a Single Simultaneous Acquisition. J Am Chem Soc 2020; 142:5793-5799. [DOI: 10.1021/jacs.0c00251] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jan Stanek
- Centre de RMN à Très Hauts Champs (FRE 2034 CNRS, UCB Lyon 1, ENS Lyon), Université de Lyon, 5 rue de la Doua, Villeurbanne 69100, France
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, Warsaw 02089, Poland
| | - Tobias Schubeis
- Centre de RMN à Très Hauts Champs (FRE 2034 CNRS, UCB Lyon 1, ENS Lyon), Université de Lyon, 5 rue de la Doua, Villeurbanne 69100, France
| | - Piotr Paluch
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, Warsaw 02089, Poland
| | - Peter Güntert
- Physical Chemistry, Eidgenössische Technische Hochschule Zurich, Hochschule Zürich, Vladimir-Prelog-Weg 2, Zurich 8093, Switzerland
- Center for Biomolecular Magnetic Resonance, Institute of Biophysical Chemistry, Goethe University Frankfurt am Main, Max-von-Laue-Str. 9, Frankfurt am Main 60438, Germany
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji 192-0397, Japan
| | - Loren B. Andreas
- Centre de RMN à Très Hauts Champs (FRE 2034 CNRS, UCB Lyon 1, ENS Lyon), Université de Lyon, 5 rue de la Doua, Villeurbanne 69100, France
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen D-37077, Germany
| | - Guido Pintacuda
- Centre de RMN à Très Hauts Champs (FRE 2034 CNRS, UCB Lyon 1, ENS Lyon), Université de Lyon, 5 rue de la Doua, Villeurbanne 69100, France
| |
Collapse
|
6
|
Kupče Ē, Mote KR, Madhu PK. Experiments with direct detection of multiple FIDs. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 304:16-34. [PMID: 31077929 DOI: 10.1016/j.jmr.2019.04.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/26/2019] [Accepted: 04/29/2019] [Indexed: 05/04/2023]
Abstract
Pulse schemes with direct observation of multiple free induction decays (FIDs) offer a dramatic increase in the spectral information content of NMR experiments and often yield substantial improvement in measurement sensitivity per unit time. Availability of multiple receivers on the state-of-the-art commercial spectrometers allows spectra from different nuclear species to be recorded in parallel routinely. Experiments with multi-FID detection have been designed with both, homonuclear and multinuclear acquisition. We provide a brief overview of such techniques designed for applications in liquid- and solid- state NMR as well as in hyperpolarized samples. Here we show how these techniques have led to design of experiments that allow structure elucidation of small molecules and resonance assignment in proteins from a single measurement. Probes with multiple RF micro-coils routed to multiple NMR receivers provide an alternative way of increasing the throughput of modern NMR systems. Solid-state NMR experiments have also benefited immensely from both parallel and simultaneous FID acquisition in a variety of multi-dimensional pulse schemes. We believe that multi-FID detection will become an essential component of the future NMR methodologies effectively increasing the information content of NMR experiments and reducing the cost of NMR analysis.
Collapse
Affiliation(s)
- Ēriks Kupče
- Bruker UK Ltd., Banner Lane, Coventry CV4 9GH, United Kingdom.
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Ranga Reddy District, Hyderabad 500107, India
| | - Perunthiruthy K Madhu
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/P Gopanpally Village, Ranga Reddy District, Hyderabad 500107, India
| |
Collapse
|
7
|
Sharma K, Madhu PK, Mote KR. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins. JOURNAL OF BIOMOLECULAR NMR 2016; 65:127-141. [PMID: 27364976 DOI: 10.1007/s10858-016-0043-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/14/2016] [Indexed: 05/04/2023]
Abstract
One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text] can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping.
Collapse
Affiliation(s)
- Kshama Sharma
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India
| | - Perunthiruthy K Madhu
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India.
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400 005, India.
| | - Kaustubh R Mote
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad, 21, Brundavan Colony, Narsingi, Hyderabad, 500 075, India.
| |
Collapse
|
8
|
Gopinath T, Veglia G. Multiple acquisitions via sequential transfer of orphan spin polarization (MAeSTOSO): How far can we push residual spin polarization in solid-state NMR? JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 267:1-8. [PMID: 27039168 PMCID: PMC4862926 DOI: 10.1016/j.jmr.2016.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/22/2016] [Accepted: 03/07/2016] [Indexed: 05/05/2023]
Abstract
Conventional multidimensional magic angle spinning (MAS) solid-state NMR (ssNMR) experiments detect the signal arising from the decay of a single coherence transfer pathway (FID), resulting in one spectrum per acquisition time. Recently, we introduced two new strategies, namely DUMAS (DUal acquisition Magic Angle Spinning) and MEIOSIS (Multiple ExperIments via Orphan SpIn operatorS), that enable the simultaneous acquisitions of multidimensional ssNMR experiments using multiple coherence transfer pathways. Here, we combined the main elements of DUMAS and MEIOSIS to harness both orphan spin operators and residual polarization and increase the number of simultaneous acquisitions. We show that it is possible to acquire up to eight two-dimensional experiments using four acquisition periods per each scan. This new suite of pulse sequences, called MAeSTOSO for Multiple Acquisitions via Sequential Transfer of Orphan Spin pOlarization, relies on residual polarization of both (13)C and (15)N pathways and combines low- and high-sensitivity experiments into a single pulse sequence using one receiver and commercial ssNMR probes. The acquisition of multiple experiments does not affect the sensitivity of the main experiment; rather it recovers the lost coherences that are discarded, resulting in a significant gain in experimental time. Both merits and limitations of this approach are discussed.
Collapse
Affiliation(s)
- T Gopinath
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States; Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, United States.
| |
Collapse
|
9
|
Molugu TR, Brown MF. Cholesterol-induced suppression of membrane elastic fluctuations at the atomistic level. Chem Phys Lipids 2016; 199:39-51. [PMID: 27154600 DOI: 10.1016/j.chemphyslip.2016.05.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 04/29/2016] [Accepted: 05/02/2016] [Indexed: 12/14/2022]
Abstract
Applications of solid-state NMR spectroscopy for investigating the influences of lipid-cholesterol interactions on membrane fluctuations are reviewed in this paper. Emphasis is placed on understanding the energy landscapes and fluctuations at an emergent atomistic level. Solid-state (2)H NMR spectroscopy directly measures residual quadrupolar couplings (RQCs) due to individual C-(2)H labeled segments of the lipid molecules. Moreover, residual dipolar couplings (RDCs) of (13)C-(1)H bonds are obtained in separated local-field NMR spectroscopy. The distributions of RQC or RDC values give nearly complete profiles of the order parameters as a function of acyl segment position. Measured equilibrium properties of glycerophospholipids and sphingolipids including their binary and tertiary mixtures with cholesterol show unequal mixing associated with liquid-ordered domains. The entropic loss upon addition of cholesterol to sphingolipids is less than for glycerophospholipids and may drive the formation of lipid rafts. In addition relaxation time measurements enable one to study the molecular dynamics over a wide time-scale range. For (2)H NMR the experimental spin-lattice (R1Z) relaxation rates follow a theoretical square-law dependence on segmental order parameters (SCD) due to collective slow dynamics over mesoscopic length scales. The functional dependence for the liquid-crystalline lipid membranes is indicative of viscoelastic properties as they emerge from atomistic-level interactions. A striking decrease in square-law slope upon addition of cholesterol denotes stiffening relative to the pure lipid bilayers that is diminished in the case of lanosterol. Measured equilibrium properties and relaxation rates infer opposite influences of cholesterol and detergents on collective dynamics and elasticity at an atomistic scale that potentially affects lipid raft formation in cellular membranes.
Collapse
Affiliation(s)
- Trivikram R Molugu
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
| | - Michael F Brown
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA; Department of Physics, University of Arizona, Tucson, AZ 85721, USA.
| |
Collapse
|
10
|
Das BB, Opella SJ. Simultaneous cross polarization to (13)C and (15)N with (1)H detection at 60kHz MAS solid-state NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 262:20-26. [PMID: 26705905 PMCID: PMC4716881 DOI: 10.1016/j.jmr.2015.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 05/05/2023]
Abstract
We describe high resolution MAS solid-state NMR experiments that utilize (1)H detection with 60kHz magic angle spinning; simultaneous cross-polarization from (1)H to (15)N and (13)C nuclei; bidirectional cross-polarization between (13)C and (15)N nuclei; detection of both amide nitrogen and aliphatic carbon (1)H; and measurement of both (13)C and (15)N chemical shifts through multi-dimensional correlation experiments. Three-dimensional experiments correlate amide (1)H and alpha (1)H selectively with (13)C or (15)N nuclei in a polypeptide chain. Two separate three-dimensional spectra correlating (1)Hα/(13)Cα/(1)H(N) and (1)H(N)/(15)N/(1)Hα are recorded simultaneously in a single experiment, demonstrating that a twofold savings in experimental time is potentially achievable. Spectral editing using bidirectional coherence transfer pathways enables simultaneous magnetization transfers between (15)N, (13)Cα(()(i)()) and (13)C'(()(i)(-1)), facilitating intra- and inter-residue correlations for sequential resonance assignment. Non-uniform sampling is integrated into the experiments, further reducing the length of experimental time.
Collapse
Affiliation(s)
- Bibhuti B Das
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stanley J Opella
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
11
|
Gopinath T, Veglia G. Multiple acquisition of magic angle spinning solid-state NMR experiments using one receiver: application to microcrystalline and membrane protein preparations. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 253:143-53. [PMID: 25797011 PMCID: PMC4399235 DOI: 10.1016/j.jmr.2015.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 01/02/2015] [Accepted: 01/04/2015] [Indexed: 05/05/2023]
Abstract
Solid-state NMR spectroscopy of proteins is a notoriously low-throughput technique. Relatively low-sensitivity and poor resolution of protein samples require long acquisition times for multidimensional NMR experiments. To speed up data acquisition, we developed a family of experiments called Polarization Optimized Experiments (POE), in which we utilized the orphan spin operators that are discarded in classical multidimensional NMR experiments, recovering them to allow simultaneous acquisition of multiple 2D and 3D experiments, all while using conventional probes with spectrometers equipped with one receiver. POE allow the concatenation of multiple 2D or 3D pulse sequences into a single experiment, thus potentially combining all of the aforementioned advances, boosting the capability of ssNMR spectrometers at least two-fold without the addition of any hardware. In this perspective, we describe the first generation of POE, such as dual acquisition MAS (or DUMAS) methods, and then illustrate the evolution of these experiments into MEIOSIS, a method that enables the simultaneous acquisition of multiple 2D and 3D spectra. Using these new pulse schemes for the solid-state NMR investigation of biopolymers makes it possible to obtain sequential resonance assignments, as well as distance restraints, in about half the experimental time. While designed for acquisition of heteronuclei, these new experiments can be easily implemented for proton detection and coupled with other recent advancements, such as dynamic nuclear polarization (DNP), to improve signal to noise. Finally, we illustrate the application of these methods to microcrystalline protein preparations as well as single and multi-span membrane proteins reconstituted in lipid membranes.
Collapse
Affiliation(s)
- T Gopinath
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States; Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, United States.
| |
Collapse
|