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Hu Y, Wang Y, Singh J, Sun R, Xu L, Niu X, Huang K, Bai G, Liu G, Zuo X, Chen C, Qin PZ, Fang X. Phosphorothioate-Based Site-Specific Labeling of Large RNAs for Structural and Dynamic Studies. ACS Chem Biol 2022; 17:2448-2460. [PMID: 36069699 PMCID: PMC10186269 DOI: 10.1021/acschembio.2c00199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Pulsed electron-electron double resonance (PELDOR) spectroscopy, X-ray scattering interferometry (XSI), and single-molecule Förster resonance energy transfer (smFRET) are molecular rulers that provide inter- or intramolecular pair-wise distance distributions in the nanometer range, thus being ideally suitable for structural and dynamic studies of biomolecules including RNAs. The prerequisite for such applications requires site-specific labeling of biomolecules with spin labels, gold nanoparticles, and fluorescent tags, respectively. Recently, site-specific labeling of large RNAs has been achieved by a combination of transcription of an expanded genetic alphabet containing A-T/G-C base pairs and NaM-TPT3 unnatural base pair (UBP) with post-transcriptional modifications at UBP bases by click chemistry or amine-NHS ester reactions. However, due to the bulky sizes of functional groups or labeling probes used, such strategies might cause structural perturbation and decrease the accuracy of distance measurements. Here, we synthesize an α-thiophosphorylated variant of rTPT3TP (rTPT3αS), which allows for post-transcriptional site-specific labeling of large RNAs at the internal α-phosphate backbone via maleimide-modified probes. Subsequent PELDOR, XSI, and smFRET measurements result in narrower distance distributions than labeling at the TPT3 base. The presented strategy provides a new route to empower the molecular rulers for structural and dynamic studies of large RNA and its complex.
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Affiliation(s)
- Yanping Hu
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yan Wang
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jaideep Singh
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Ruirui Sun
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lilei Xu
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaolin Niu
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Keyun Huang
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Guangcan Bai
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Guoquan Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, Lemont Illinois 60439, United States
| | - Chunlai Chen
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Xianyang Fang
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
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Miao Q, Nitsche C, Orton H, Overhand M, Otting G, Ubbink M. Paramagnetic Chemical Probes for Studying Biological Macromolecules. Chem Rev 2022; 122:9571-9642. [PMID: 35084831 PMCID: PMC9136935 DOI: 10.1021/acs.chemrev.1c00708] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/11/2022]
Abstract
Paramagnetic chemical probes have been used in electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopy for more than four decades. Recent years witnessed a great increase in the variety of probes for the study of biological macromolecules (proteins, nucleic acids, and oligosaccharides). This Review aims to provide a comprehensive overview of the existing paramagnetic chemical probes, including chemical synthetic approaches, functional properties, and selected applications. Recent developments have seen, in particular, a rapid expansion of the range of lanthanoid probes with anisotropic magnetic susceptibilities for the generation of structural restraints based on residual dipolar couplings and pseudocontact shifts in solution and solid state NMR spectroscopy, mostly for protein studies. Also many new isotropic paramagnetic probes, suitable for NMR measurements of paramagnetic relaxation enhancements, as well as EPR spectroscopic studies (in particular double resonance techniques) have been developed and employed to investigate biological macromolecules. Notwithstanding the large number of reported probes, only few have found broad application and further development of probes for dedicated applications is foreseen.
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Affiliation(s)
- Qing Miao
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- School
of Chemistry &Chemical Engineering, Shaanxi University of Science & Technology, Xi’an710021, China
| | - Christoph Nitsche
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Henry Orton
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Mark Overhand
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Gottfried Otting
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Marcellus Ubbink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
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Nguyen PH, Popova AM, Hideg K, Qin PZ. A nucleotide-independent cyclic nitroxide label for monitoring segmental motions in nucleic acids. BMC BIOPHYSICS 2015; 8:6. [PMID: 25897395 PMCID: PMC4404236 DOI: 10.1186/s13628-015-0019-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/16/2015] [Indexed: 01/07/2023]
Abstract
Background Spin labels, which are chemically stable radicals attached at specific sites of a bio-molecule, enable investigations on structure and dynamics of proteins and nucleic acids using techniques such as site-directed spin labeling and paramagnetic NMR. Among spin labels developed, the class of rigid labels have limited or no independent motions between the radical bearing moiety and the target, and afford a number of advantages in measuring distances and monitoring local dynamics within the parent bio-molecule. However, a general method for attaching a rigid label to nucleic acids in a nucleotide-independent manner has not been reported. Results We developed an approach for installing a nearly rigid nitroxide spin label, designated as R5c, at a specific site of the nucleic acid backbone in a nucleotide-independent manner. The method uses a post-synthesis approach to covalently attach the nitroxide moiety in a cyclic fashion to phosphorothioate groups introduced at two consecutive nucleotides of the target strand. R5c-labeled nucleic acids are capable of pairing with their respective complementary strands, and the cyclic nature of R5c attachment significantly reduced independence motions of the label with respect to the parent duplex, although it may cause distortion of the local environment at the site of labeling. R5c yields enhanced sensitivity to the collective motions of the duplex, as demonstrated by its capability to reveal changes in collective motions of the substrate recognition duplex of the 120-kDa Tetrahymena group I ribozyme, which elude detection by a flexible label. Conclusions The cyclic R5c nitroxide can be efficiently attached to a target nucleic acid site using a post-synthetic coupling approach conducted under mild biochemical conditions, and serves as a viable label for experimental investigation of segmental motions in nucleic acids, including large folded RNAs. Electronic supplementary material The online version of this article (doi:10.1186/s13628-015-0019-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Phuong H Nguyen
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA ; Current Address: Bachem Americas, Torrance, CA 90505 USA
| | - Anna M Popova
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA ; Current Address: Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037 USA
| | - Kálmán Hideg
- Institute of Organic and Medicinal Chemistry, University of Pécs, Szigetic Strasse 12, Pécs, Hungary
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, CA 90089-0744 USA
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Tangprasertchai NS, Zhang X, Ding Y, Tham K, Rohs R, Haworth IS, Qin PZ. An Integrated Spin-Labeling/Computational-Modeling Approach for Mapping Global Structures of Nucleic Acids. Methods Enzymol 2015; 564:427-53. [PMID: 26477260 PMCID: PMC4641853 DOI: 10.1016/bs.mie.2015.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The technique of site-directed spin labeling (SDSL) provides unique information on biomolecules by monitoring the behavior of a stable radical tag (i.e., spin label) using electron paramagnetic resonance (EPR) spectroscopy. In this chapter, we describe an approach in which SDSL is integrated with computational modeling to map conformations of nucleic acids. This approach builds upon a SDSL tool kit previously developed and validated, which includes three components: (i) a nucleotide-independent nitroxide probe, designated as R5, which can be efficiently attached at defined sites within arbitrary nucleic acid sequences; (ii) inter-R5 distances in the nanometer range, measured via pulsed EPR; and (iii) an efficient program, called NASNOX, that computes inter-R5 distances on given nucleic acid structures. Following a general framework of data mining, our approach uses multiple sets of measured inter-R5 distances to retrieve "correct" all-atom models from a large ensemble of models. The pool of models can be generated independently without relying on the inter-R5 distances, thus allowing a large degree of flexibility in integrating the SDSL-measured distances with a modeling approach best suited for the specific system under investigation. As such, the integrative experimental/computational approach described here represents a hybrid method for determining all-atom models based on experimentally-derived distance measurements.
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Affiliation(s)
| | - Xiaojun Zhang
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Yuan Ding
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Kenneth Tham
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Remo Rohs
- Department of Chemistry, University of Southern California, Los Angeles, California, USA,Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Ian S. Haworth
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Peter Z. Qin
- Department of Chemistry, University of Southern California, Los Angeles, California, USA,Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, California, USA,Corresponding author:
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Ding Y, Zhang X, Tham KW, Qin PZ. Experimental mapping of DNA duplex shape enabled by global lineshape analyses of a nucleotide-independent nitroxide probe. Nucleic Acids Res 2014; 42:e140. [PMID: 25092920 PMCID: PMC4191381 DOI: 10.1093/nar/gku695] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Sequence-dependent variation in structure and dynamics of a DNA duplex, collectively referred to as ‘DNA shape’, critically impacts interactions between DNA and proteins. Here, a method based on the technique of site-directed spin labeling was developed to experimentally map shapes of two DNA duplexes that contain response elements of the p53 tumor suppressor. An R5a nitroxide spin label, which was covalently attached at a specific phosphate group, was scanned consecutively through the DNA duplex. X-band continuous-wave electron paramagnetic resonance spectroscopy was used to monitor rotational motions of R5a, which report on DNA structure and dynamics at the labeling site. An approach based on Pearson's coefficient analysis was developed to collectively examine the degree of similarity among the ensemble of R5a spectra. The resulting Pearson's coefficients were used to generate maps representing variation of R5a mobility along the DNA duplex. The R5a mobility maps were found to correlate with maps of certain DNA helical parameters, and were capable of revealing similarity and deviation in the shape of the two closely related DNA duplexes. Collectively, the R5a probe and the Pearson's coefficient-based lineshape analysis scheme yielded a generalizable method for examining sequence-dependent DNA shapes.
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Affiliation(s)
- Yuan Ding
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiaojun Zhang
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Kenneth W Tham
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
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Esquiaqui JM, Sherman EM, Ionescu SA, Ye JD, Fanucci GE. Characterizing the dynamics of the leader-linker interaction in the glycine riboswitch with site-directed spin labeling. Biochemistry 2014; 53:3526-8. [PMID: 24849816 PMCID: PMC4059530 DOI: 10.1021/bi500404b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Site-directed
spin labeling with continuous wave electron paramagnetic
resonance (EPR) spectroscopy was utilized to characterize dynamic
features of the kink–turn motif formed through a leader–linker
interaction in the Vibrio cholerae glycine riboswitch.
Efficient incorporation of spin-labels into select sites within the
phosphate backbone of the leader–linker region proceeded via
splinted ligation of chemically synthesized spin-labeled oligonucleotides
to in vitro transcribed larger RNA fragments. The
resultant nitroxide EPR line shapes have spectral characteristics
consistent with a kink–turn motif and reveal differential backbone
dynamics that are modulated by the presence of magnesium, potassium,
and glycine.
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Affiliation(s)
- Jackie M Esquiaqui
- Department of Chemistry, University of Florida , P.O. Box 117200, Gainesville, Florida 32611, United States
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Franck JM, Scott JA, Han S. Nonlinear scaling of surface water diffusion with bulk water viscosity of crowded solutions. J Am Chem Soc 2013; 135:4175-8. [PMID: 23347324 PMCID: PMC3785640 DOI: 10.1021/ja3112912] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The translational hydration dynamics within 0.5-1.5 nm of the surface of a DPPC liposome, a model biomacromolecular surface, is analyzed by the recently developed Overhauser dynamic nuclear polarization (ODNP) technique. We find that dramatic changes to the bulk solvent cause only weak changes in the surface hydration dynamics. Specifically, both a >10-fold increase in bulk viscosity and the restriction of diffusion by confinement on a multiple nm length-scale change the local translational diffusion coefficient of the surface water surrounding the lipid bilayer by <2.5-fold. By contrast, previous ODNP studies have shown that changes to the biomacromolecular surface induced by folding, binding, or aggregation can cause local hydration dynamics to vary by factors of up to 30. We suggest that the surface topology and chemistry at the ≤1.5 nm scale, rather than the characteristics of the solvent, nearly exclusively determine the macromolecule's surface hydration dynamics.
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Affiliation(s)
- John M. Franck
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
| | - John A. Scott
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
| | - Songi Han
- Dept. of Chemistry and Biochemistry, University of California, Santa Barbara
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Popova AM, Hatmal MM, Frushicheva M, Price EA, Qin PZ, Haworth IS. Nitroxide sensing of a DNA microenvironment: mechanistic insights from EPR spectroscopy and molecular dynamics simulations. J Phys Chem B 2012; 116:6387-96. [PMID: 22574834 PMCID: PMC3382087 DOI: 10.1021/jp303303v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The behavior of the nitroxide spin labels 1-oxyl-4-bromo-2,2,5,5-tetramethylpyrroline (R5a) and 1-oxyl-2,2,5,5-tetramethylpyrroline (R5) attached at a phosphorothioate-substituted site in a DNA duplex is modulated by the DNA in a site- and stereospecific manner. A better understanding of the mechanisms of R5a/R5 sensing of the DNA microenvironment will enhance our capability to relate information from nitroxide spectra to sequence-dependent properties of DNA. Toward this goal, electron paramagnetic resonance (EPR) spectroscopy and molecular dynamics (MD) simulations were used to investigate R5 and R5a attached as R(p) and S(p) diastereomers at phosphorothioate (pS)C(7) of d(CTACTG(pS)C(7)Y(8)TTAG). d(CTAAAGCAGTAG) (Y = T or U). X-band continuous-wave EPR spectra revealed that the dT(8) to dU(8) change alters nanosecond rotational motions of R(p)-R5a but produces no detectable differences for S(p)-R5a, R(p)-R5, and S(p)-R5. MD simulations were able to qualitatively account for these spectral variations and provide a plausible physical basis for the R5/R5a behavior. The simulations also revealed a correlation between DNA backbone B(I)/B(II) conformations and R5/R5a rotational diffusion, thus suggesting a direct connection between DNA local backbone dynamics and EPR-detectable R5/R5a motion. These results advance our understanding of how a DNA microenvironment influences nitroxide motion and the observed EPR spectra. This may enable use of R5/R5a for a quantitative description of the sequence-dependent properties of large biologically relevant DNA molecules.
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Affiliation(s)
- Anna M. Popova
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744
| | - Ma’mon M. Hatmal
- Department of Biochemistry, University of Southern California, Los Angeles, California 90033-1039
| | - Maria Frushicheva
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744
| | - Eric A. Price
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089-0744
| | - Peter Z. Qin
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744
| | - Ian S. Haworth
- Department of Biochemistry, University of Southern California, Los Angeles, California 90033-1039
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90089-9121
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Nguyen P, Qin PZ. RNA dynamics: perspectives from spin labels. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:62-72. [PMID: 21882345 DOI: 10.1002/wrna.104] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Dynamics are important and indispensible physical attributes that play essential roles in RNA function. RNA dynamics are complex, spanning vast timescales, and encompassing a large number of physical modes. The technique of site-directed spin labeling (SDSL), which derives information on local structural and dynamic features of a macromolecule by monitoring a chemically stable nitroxide radical using electron paramagnetic resonance spectroscopy, has been applied to monitor intrinsic dynamics at defined structural states as well as to probe conformational transition dynamics of RNAs. The current state of SDSL studies of RNA dynamics is summarized here. Further development and application of SDSL promise to open up many more opportunities for probing RNA dynamics and connecting dynamics to structure and function.
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Affiliation(s)
- Phuong Nguyen
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
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Pulsed electron-electron double resonance: beyond nanometre distance measurements on biomacromolecules. Biochem J 2011; 434:353-63. [PMID: 21348855 DOI: 10.1042/bj20101871] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PELDOR (or DEER; pulsed electron-electron double resonance) is an EPR (electron paramagnetic resonance) method that measures via the dipolar electron-electron coupling distances in the nanometre range, currently 1.5-8 nm, with high precision and reliability. Depending on the quality of the data, the error can be as small as 0.1 nm. Beyond mere mean distances, PELDOR yields distance distributions, which provide access to conformational distributions and dynamics. It can also be used to count the number of monomers in a complex and allows determination of the orientations of spin centres with respect to each other. If, in addition to the dipolar through-space coupling, a through-bond exchange coupling mechanism contributes to the overall coupling both mechanisms can be separated and quantified. Over the last 10 years PELDOR has emerged as a powerful new biophysical method without size restriction to the biomolecule to be studied, and has been applied to a large variety of nucleic acids as well as proteins and protein complexes in solution or within membranes. Small nitroxide spin labels, paramagnetic metal ions, amino acid radicals or intrinsic clusters and cofactor radicals have been used as spin centres.
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Studying biomolecular complexes with pulsed electron–electron double resonance spectroscopy. Biochem Soc Trans 2011; 39:128-39. [DOI: 10.1042/bst0390128] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The function of biomolecules is intrinsically linked to their structure and the complexes they form during function. Techniques for the determination of structures and dynamics of these nanometre assemblies are therefore important for an understanding on the molecular level. PELDOR (pulsed electron–electron double resonance) is a pulsed EPR method that can be used to reliably and precisely measure distances in the range 1.5–8 nm, to unravel orientations and to determine the number of monomers in complexes. In conjunction with site-directed spin labelling, it can be applied to biomolecules of all sizes in aqueous solutions or membranes. PELDOR is therefore complementary to the methods of X-ray crystallography, NMR and FRET (fluorescence resonance energy transfer) and is becoming a powerful method for structural determination of biomolecules. In the present review, the methods of PELDOR are discussed and examples where PELDOR has been used to obtain structural information on biomolecules are summarized.
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Shelke SA, Sigurdsson ST. Site-Directed Nitroxide Spin Labeling of Biopolymers. STRUCTURAL INFORMATION FROM SPIN-LABELS AND INTRINSIC PARAMAGNETIC CENTRES IN THE BIOSCIENCES 2011. [DOI: 10.1007/430_2011_62] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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