ArticleProceedings of the National Academy of Sciences of the United States of America2011
Structure and dynamics of a conformationally constrained nitroxide side chain and applications in EPR spectroscopy.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 77 papers.
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Who cites it
77 citing papers in PubMed.
- A dynamic duo: Copper metalloregulators and continuous-wave electron spin resonance spectroscopy.Biophysical reports · 2026Review
- Nitroxide spin, non-canonical amino acids and SDSL-EPR spectroscopy: a winning combination for protein dynamics studies.European biophysics journal : EBJ · 2026Article
- EPR Techniques to Probe Insertion and Conformation of Spin-Labeled Proteins in Lipid Bilayers.Methods in molecular biology (Clifton, N.J.) · 2026Article
- Rational Design of a Cu(II) Spin Label Improves the Sensitivity of Distance Measurements.The journal of physical chemistry letters · 2025Article
- HMGB1 B-Box Domain Associates Promote Protein-Polyelectrolyte Interactions.The journal of physical chemistry. B · 2025Article
- Rigid and stable nitroxide spin label for high-resolution distance measurements on proteins by DEER experiments.Magnetic resonance letters · 2025Article
- Protein Modeling with DEER Spectroscopy.Annual review of biophysics · 2025Review
- Structural Dynamics of Protein Interactions Using Site-Directed Spin Labeling of Cysteines to Measure Distances and Rotational Dynamics with EPR Spectroscopy.Applied magnetic resonance · 2024Article
- Modeling of Cu(II)-based protein spin labels using rotamer libraries.Physical chemistry chemical physics : PCCP · 2024Article
- A Highly Ordered Nitroxide Side Chain for Distance Mapping and Monitoring Slow Structural Fluctuations in Proteins.Applied magnetic resonance · 2024Article
- Electron paramagnetic resonance spectroscopic characterization of the human KCNE3 protein in lipodisq nanoparticles for structural dynamics of membrane proteins.Biophysical chemistry · 2023Article
- A novel approach to modeling side chain ensembles of the bifunctional spin label RX.bioRxiv : the preprint server for biology · 2023Article
- Enzymatic Spin-Labeling of Protein N- and C-Termini for Electron Paramagnetic Resonance Spectroscopy.Bioconjugate chemistry · 2023Article
- Different Biophysical Properties of Cell Surface α2,3- and α2,6-Sialoglycans Revealed by Electron Paramagnetic Resonance Spectroscopic Studies.The journal of physical chemistry. B · 2023Article
- Comparative evaluation of spin-label modeling methods for protein structural studies.Biophysical journal · 2022Article
- Cross-validation of distance measurements in proteins by PELDOR/DEER and single-molecule FRET.Nature communications · 2022Article
- Beyond structure: Deciphering site-specific dynamics in proteins from double histidine-based EPR measurements.Protein science : a publication of the Protein Society · 2022Article
- Paramagnetic Chemical Probes for Studying Biological Macromolecules.Chemical reviews · 2022Review
- Organic radical materials in biomedical applications: State of the art and perspectives.Exploration (Beijing, China) · 2022Article
- DEER Analysis of GPCR Conformational Heterogeneity.Biomolecules · 2021Review
17 more citing papers are in PubMed but not listed here.
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7 authors.
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Abstract
A disulfide-linked nitroxide side chain (R1) is the most widely used spin label for determining protein topology, mapping structural changes, and characterizing nanosecond backbone motions by site-directed spin labeling. Although the internal motion of R1 and the number of preferred rotamers are limited, translating interspin distance measurements and spatial orientation information into structural constraints is challenging. Here, we introduce a highly constrained nitroxide side chain designated RX as an alternative to R1 for these applications. RX is formed by a facile cross-linking reaction of a bifunctional methanethiosulfonate reagent with pairs of cysteine residues at i and i + 3 or i and i + 4 in an α-helix, at i and i + 2 in a β-strand, or with cysteine residues in adjacent strands in a β-sheet. Analysis of EPR spectra, a crystal structure of RX in T4 lysozyme, and pulsed electron-electron double resonance (ELDOR) spectroscopy on an immobilized protein containing RX all reveal a highly constrained internal motion of the side chain. Consistent with the constrained geometry, interspin distance distributions between pairs of RX side chains are narrower than those from analogous R1 pairs. As an important consequence of the constrained internal motion of RX, spectral diffusion detected with ELDOR reveals microsecond internal motions of the protein. Collectively, the data suggest that the RX side chain will be useful for distance mapping by EPR spectroscopy, determining spatial orientation of helical segments in oriented specimens, and measuring structural fluctuations on the microsecond time scale.
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