Microsecond Dynamics in Ubiquitin Probed by Solid‐State 15N NMR Spectroscopy R1ρ Relaxation Experiments under Fast MAS (60–110 kHz). Issue 39 (20th June 2017)

• Record Type: Journal Article
• Authors: Lakomek, Nils‐Alexander; Penzel, Susanne; Lends, Alons; Cadalbert, Riccardo; Ernst, Matthias; Meier, Beat H.
• Is Part Of: Chemistry. Volume 23:Issue 39(2017)
• Page Start: 9425
• Page End: 9433
• Publication Date: 2017-06-20
• Subjects: biophysics -- molecular dynamics -- NMR spectroscopy -- proteins -- solid-state structures; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201701738
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: 15 N R 1ρ relaxation experiments in solid‐state NMR spectroscopy are sensitive to timescales and amplitudes of internal protein motions in the hundreds of nano‐ to microsecond time window, which is difficult to probe by solution‐state NMR spectroscopy. By using 15 N R 1ρ relaxation experiments, a simplified approach to detect low microsecond protein dynamics is described and residue‐specific correlation times are determined from the ratio of 15 N R 1ρ rate constants at different magic angle spinning frequencies. Microcrystalline ubiquitin exhibits small‐amplitude dynamics on a timescale of about 1 μs across the entire protein, and larger amplitude motions, also on the 1 μs timescale, for several sites, including the β1 –β2 turn and the N terminus of the α helix. According to the analysis, the microsecond protein backbone dynamics are of lower amplitude than that concluded in previous solid‐state NMR spectroscopy studies, but persist across the entire protein with a rather uniform timescale of 1 μs. Abstract : Just relax ! Solid‐state 15 N R1ρ NMR relaxation experiments under fast magic angle spinning (MAS; 60–110 kHz) are used to investigate the internal backbone dynamics in microcrystalline ubiquitin (see figure). Small‐amplitude backbone dynamics across the entire protein are found on a timescale of about 1–2 μs and larger amplitude motion is found for several sites, including the first β1 –β2 turn and N terminus of the α helix on the same 1–2 μs timescale.