@misc{21145, abstract = {Protein conformational energy landscapes are shaped not only by intramolecular interactions but also by their environment. In protein crystals and protein-protein complexes, intermolecular contacts alter this energy landscape, but the exact nature of this alteration is difficult to decipher. Understanding how the crystal lattice affects protein dynamics is crucial for crystallography-based studies of motion, yet its influence on collective motions remains unclear. Aromatic ring flips in the hydrophobic core represent sensitive probes of such dynamics. Here, we compare the kinetics of aromatic ring flips in the protein GB1 in crystals, in complex with its binding partner IgG, and in solution, combining advanced isotope labeling with quantitative NMR methods. We show that rings in the core flip nearly a thousand times less frequently in crystals than in solution. Enhanced-sampling molecular dynamics simulations, based on a new crystal structure, reproduce these elevated barriers and reveal how the crystal restrains motions. }, author = {Becker, Lea Marie and Schanda, Paul and Chipot, Christophe}, publisher = {Institute of Science and Technology Austria}, title = {{Additional Data for "Aromatic Ring Flips Reveal Reshaping of Protein Dynamics in Crystals and Complexes"}}, doi = {10.15479/AT-ISTA-21145}, year = {2026}, } @misc{21284, abstract = {The advantageous characteristics attributed to the 19F nucleus have made it a popular target for NMR once again in recent years. Aside from solution NMR, an increasing number of studies have been conducted applying solid-state magic-angle-spinning NMR to fluorine-labeled samples. Here, the high chemical shift anisotropy and strong dipolar couplings can be utilized to get structural insights into proteins and measure long distances. Despite increasing popularity and promising benefits, the sensitivity of biomolecular 19F MAS NMR often suffers from slow longitudinal T1 relaxation and therefore long recycle delays. In this work, we expand paramagnetic doping, an approach commonly used to reduce proton T1 relaxation times, to 19F-labeled biological samples. We study the effect of Gd(DTPA) and Gd(DTPA-BMA) on 19F and 13C T1 and T2 relaxation in a [5-19F13C]-tryptophan-labeled protein via 19F-detected MAS NMR experiments. The observed paramagnetic relaxation enhancement substantially reduces measurement times of 19F MAS NMR experiments without compromising resolution. Additionally, we report the chemical-shift assignments of all four fluorotryptophan signals in the 12 × 39 kDa large protein using a mutagenesis approach.}, author = {Becker, Lea Marie and Schanda, Paul}, publisher = {Institute of Science and Technology Austria}, title = {{Research data for "Accelerated 19F biomolecular magic-angle spinning NMR with paramagnetic dopants"}}, doi = {10.15479/AT-ISTA-21284}, year = {2026}, } @article{21777, abstract = {The advantageous characteristics attributed to the 19F nucleus have made it a popular target for nuclear magnetic resonance (NMR) once again in recent years. Aside from solution NMR, an increasing number of studies have been conducted applying solid-state magic-angle spinning (MAS) NMR to fluorine-labelled samples. Here, the high chemical shift anisotropy and strong dipolar couplings can be utilised to get structural insights into proteins and measure long distances. Despite increasing popularity and promising benefits, the sensitivity of biomolecular 19F MAS NMR often suffers from slow longitudinal T1 relaxation and therefore long recycle delays. In this work, we expand paramagnetic doping, an approach commonly used to reduce proton T1 relaxation times, to 19F-labelled biological samples. We study the effect of Gd(DTPA) and Gd(DTPA-BMA) on 19F T1 and T2, and 13C T1 and T2 relaxation in a [5-19F13C]-tryptophan-labelled protein via 19F-detected MAS NMR experiments. The observed paramagnetic relaxation enhancement substantially reduces measurement times of 19F MAS NMR experiments without compromising resolution. Additionally, we report the chemical shift assignments of all four fluorotryptophan signals in the 12×39 kDa-large protein TET2 using a mutagenesis approach.}, author = {Becker, Lea Marie and Toscano, Giorgia and Kapitonova, Anna and Singh, Rajkumar and Guillerm, Undina and Lichtenecker, Roman J. and Schanda, Paul}, issn = {2699-0016}, journal = {Magnetic Resonance}, number = {1}, pages = {29--37}, publisher = {Copernicus Publications}, title = {{Accelerated 19F biomolecular magic-angle spinning NMR with paramagnetic dopants}}, doi = {10.5194/mr-7-29-2026}, volume = {7}, year = {2026}, } @misc{20641, abstract = {Protein conformational energy landscapes are shaped not only by intramolecular interactions but also by their environment. In protein crystals and protein-protein complexes, intermolecular contacts alter this energy landscape, but the exact nature of this alteration is difficult to decipher. Understanding how the crystal lattice affects protein dynamics is crucial for crystallography-based studies of motion, yet its influence on collective motions remains unclear. Aromatic ring flips in the hydrophobic core represent sensitive probes of such dynamics. Here, we compare the kinetics of aromatic ring flips in the protein GB1 in crystals, in complex with its binding partner IgG, and in solution, combining advanced isotope labeling with quantitative NMR methods. We show that rings in the core flip nearly a thousand times less frequently in crystals than in solution. Enhanced-sampling molecular dynamics simulations, based on a new crystal structure, reproduce these elevated barriers and reveal how the crystal restrains motions. }, author = {Becker, Lea Marie and Schanda, Paul}, publisher = {Institute of Science and Technology Austria}, title = {{Data for "Aromatic Ring Flips Reveal Reshaping of Protein Dynamics in Crystals and Complexes"}}, doi = {10.15479/AT-ISTA-20641}, year = {2025}, } @article{17161, abstract = {Dynamic processes in molecules can occur on a wide range of timescales, and it is important to understand which timescales of motion contribute to different parameters used in dynamics measurements. For spin relaxation, this can easily be understood from the sampling frequencies of the spectral-density function by different relaxation-rate constants. In addition to data from relaxation measurements, determining dynamically averaged anisotropic interactions in magic-angle spinning (MAS) solid-state NMR allows for better quantification of the amplitude of molecular motion. For partially averaged anisotropic interactions, the relevant timescales of motion are not so clearly defined. Whether the averaging depends on the experimental methods (e.g., pulse sequences) or conditions (e.g., MAS frequency, magnitude of anisotropic interaction, radio-frequency field amplitudes) is not fully understood. To investigate these questions, we performed numerical simulations of dynamic systems based on the stochastic Liouville equation using several experiments for recoupling the dipolar coupling, chemical-shift anisotropy or quadrupolar coupling. As described in the literature, the transition between slow motion, where parameters characterizing the anisotropic interaction are not averaged, and fast motion, where the tensors are averaged leading to a scaled anisotropic quantity, occurs over a window of motional rate constants that depends mainly on the strength of the interaction. This transition region can span 2 orders of magnitude in exchange-rate constants (typically in the microsecond range) but depends only marginally on the employed recoupling scheme or sample spinning frequency. The transition region often coincides with a fast relaxation of coherences, making precise quantitative measurements difficult. Residual couplings in off-magic-angle experiments, however, average over longer timescales of motion. While in principle one may gain information on the timescales of motion from the transition area, extracting such information is hampered by low signal-to-noise ratio in experimental spectra due to fast relaxation that occurs in the same region.}, author = {Aebischer, Kathrin and Becker, Lea Marie and Schanda, Paul and Ernst, Matthias}, issn = {2699-0016}, journal = {Magnetic Resonance}, number = {1}, pages = {69--86}, publisher = {Copernicus Publications}, title = {{Evaluating the motional timescales contributing to averaged anisotropic interactions in MAS solid-state NMR}}, doi = {10.5194/mr-5-69-2024}, volume = {5}, year = {2024}, } @article{12114, abstract = {Probing the dynamics of aromatic side chains provides important insights into the behavior of a protein because flips of aromatic rings in a protein’s hydrophobic core report on breathing motion involving a large part of the protein. Inherently invisible to crystallography, aromatic motions have been primarily studied by solution NMR. The question how packing of proteins in crystals affects ring flips has, thus, remained largely unexplored. Here we apply magic-angle spinning NMR, advanced phenylalanine 1H-13C/2H isotope labeling and MD simulation to a protein in three different crystal packing environments to shed light onto possible impact of packing on ring flips. The flips of the two Phe residues in ubiquitin, both surface exposed, appear remarkably conserved in the different crystal forms, even though the intermolecular packing is quite different: Phe4 flips on a ca. 10–20 ns time scale, and Phe45 are broadened in all crystals, presumably due to µs motion. Our findings suggest that intramolecular influences are more important for ring flips than intermolecular (packing) effects.}, author = {Gauto, Diego F. and Lebedenko, Olga O. and Becker, Lea Marie and Ayala, Isabel and Lichtenecker, Roman and Skrynnikov, Nikolai R. and Schanda, Paul}, issn = {2590-1524}, journal = {Journal of Structural Biology: X}, keywords = {Structural Biology}, publisher = {Elsevier}, title = {{Aromatic ring flips in differently packed ubiquitin protein crystals from MAS NMR and MD}}, doi = {10.1016/j.yjsbx.2022.100079}, volume = {7}, year = {2023}, } @article{14036, abstract = {Magic-angle spinning (MAS) nuclear magnetic resonance (NMR) is establishing itself as a powerful method for the characterization of protein dynamics at the atomic scale. We discuss here how R1ρ MAS relaxation dispersion NMR can explore microsecond-to-millisecond motions. Progress in instrumentation, isotope labeling, and pulse sequence design has paved the way for quantitative analyses of even rare structural fluctuations. In addition to isotropic chemical-shift fluctuations exploited in solution-state NMR relaxation dispersion experiments, MAS NMR has a wider arsenal of observables, allowing to see motions even if the exchanging states do not differ in their chemical shifts. We demonstrate the potential of the technique for probing motions in challenging large enzymes, membrane proteins, and protein assemblies.}, author = {Napoli, Federico and Becker, Lea Marie and Schanda, Paul}, issn = {1879-033X}, journal = {Current Opinion in Structural Biology}, number = {10}, publisher = {Elsevier}, title = {{Protein dynamics detected by magic-angle spinning relaxation dispersion NMR}}, doi = {10.1016/j.sbi.2023.102660}, volume = {82}, year = {2023}, } @misc{12497, abstract = {Aromatic side chains are important reporters of the plasticity of proteins, and often form important contacts in protein–protein interactions. We studied aromatic residues in the two structurally homologous cross-β amyloid fibrils HET-s, and HELLF by employing a specific isotope-labeling approach and magic-angle-spinning NMR. The dynamic behavior of the aromatic residues Phe and Tyr indicates that the hydrophobic amyloid core is rigid, without any sign of "breathing motions" over hundreds of milliseconds at least. Aromatic residues exposed at the fibril surface have a rigid ring axis but undergo ring flips on a variety of time scales from nanoseconds to microseconds. Our approach provides direct insight into hydrophobic-core motions, enabling a better evaluation of the conformational heterogeneity generated from an NMR structural ensemble of such amyloid cross-β architecture.}, author = {Becker, Lea Marie and Schanda, Paul}, keywords = {aromatic side chains, isotopic labeling, protein dynamics, ring flips, spin relaxation}, publisher = {Institute of Science and Technology Austria}, title = {{Research data to: The rigid core and flexible surface of amyloid fibrils probed by magic-angle-spinning NMR spectroscopy of aromatic residues}}, doi = {10.15479/AT:ISTA:12497}, year = {2023}, } @article{12675, abstract = {Aromatic side chains are important reporters of the plasticity of proteins, and often form important contacts in protein--protein interactions. By studying a pair of structurally homologous cross-β amyloid fibrils, HET-s and HELLF, with a specific isotope-labeling approach and magic-angle-spinning (MAS) NMR, we have characterized the dynamic behavior of Phe and Tyr aromatic rings to show that the hydrophobic amyloid core is rigid, without any sign of "breathing motions" over hundreds of milliseconds at least. Aromatic residues exposed at the fibril surface have a rigid ring axis but undergo ring flips, on a variety of time scales from ns to µs. Our approach provides direct insight into hydrophobic-core motions, enabling a better evaluation of the conformational heterogeneity generated from a NMR structural ensemble of such amyloid cross-β architecture.}, author = {Becker, Lea Marie and Berbon, Mélanie and Vallet, Alicia and Grelard, Axelle and Morvan, Estelle and Bardiaux, Benjamin and Lichtenecker, Roman and Ernst, Matthias and Loquet, Antoine and Schanda, Paul}, issn = {1521-3773}, journal = {Angewandte Chemie International Edition}, keywords = {General Chemistry, Catalysis}, number = {19}, publisher = {Wiley}, title = {{The rigid core and flexible surface of amyloid fibrils probed by Magic‐Angle Spinning NMR of aromatic residues}}, doi = {10.1002/anie.202219314}, volume = {62}, year = {2023}, } @article{14835, abstract = {Aromatische Seitenketten sind wichtige Indikatoren für die Plastizität von Proteinen und bilden oft entscheidende Kontakte bei Protein‐Protein‐Wechselwirkungen. Wir untersuchten aromatische Reste in den beiden strukturell homologen cross‐β Amyloidfibrillen HET‐s und HELLF mit Hilfe eines spezifischen Ansatzes zur Isotopenmarkierung und Festkörper NMR mit Drehung am magischen Winkel. Das dynamische Verhalten der aromatischen Reste Phe und Tyr deutet darauf hin, dass der hydrophobe Amyloidkern starr ist und keine Anzeichen von “atmenden Bewegungen” auf einer Zeitskala von Hunderten von Millisekunden zeigt. Aromatische Reste, die exponiert an der Fibrillenoberfläche sitzen, haben zwar eine starre Ringachse, weisen aber Ringflips auf verschiedenen Zeitskalen von Nanosekunden bis Mikrosekunden auf. Unser Ansatz bietet einen direkten Einblick in die Bewegungen des hydrophoben Kerns und ermöglicht eine bessere Bewertung der Konformationsheterogenität, die aus einem NMR‐Strukturensemble einer solchen Cross‐β‐Amyloidstruktur hervorgeht.}, author = {Becker, Lea Marie and Berbon, Mélanie and Vallet, Alicia and Grelard, Axelle and Morvan, Estelle and Bardiaux, Benjamin and Lichtenecker, Roman and Ernst, Matthias and Loquet, Antoine and Schanda, Paul}, issn = {1521-3757}, journal = {Angewandte Chemie}, keywords = {General Medicine}, number = {19}, publisher = {Wiley}, title = {{Der starre Kern und die flexible Oberfläche von Amyloidfibrillen – Magic‐Angle‐Spinning NMR Spektroskopie von aromatischen Resten}}, doi = {10.1002/ange.202219314}, volume = {135}, year = {2023}, } @misc{14861, abstract = {Cover Page}, author = {Becker, Lea Marie and Berbon, Mélanie and Vallet, Alicia and Grelard, Axelle and Morvan, Estelle and Bardiaux, Benjamin and Lichtenecker, Roman and Ernst, Matthias and Loquet, Antoine and Schanda, Paul}, booktitle = {Angewandte Chemie International Edition}, issn = {1521-3773}, keywords = {General Chemistry, Catalysis}, number = {19}, publisher = {Wiley}, title = {{Cover Picture: The rigid core and flexible surface of amyloid fibrils probed by Magic‐Angle‐Spinning NMR spectroscopy of aromatic residues}}, doi = {10.1002/anie.202304138}, volume = {62}, year = {2023}, }