Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements

article Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements published yes Vilius Kurauskas author Emmanuelle Weber author Audrey Hessel author Isabel Ayala author Dominique Marion author Paul Schanda author 7B541462-FAF6-11E9-A490-E8DFE56974250000-0002-9350-7606 Transverse relaxation rate measurements in magic-angle spinning solid-state nuclear magnetic resonance provide information about molecular motions occurring on nanosecond-to-millisecond (ns–ms) time scales. The measurement of heteronuclear (13C, 15N) relaxation rate constants in the presence of a spin-lock radiofrequency field (R1ρ relaxation) provides access to such motions, and an increasing number of studies involving R1ρ relaxation in proteins have been reported. However, two factors that influence the observed relaxation rate constants have so far been neglected, namely, (1) the role of CSA/dipolar cross-correlated relaxation (CCR) and (2) the impact of fast proton spin flips (i.e., proton spin diffusion and relaxation). We show that CSA/D CCR in R1ρ experiments is measurable and that the CCR rate constant depends on ns–ms motions; it can thus provide insight into dynamics. We find that proton spin diffusion attenuates this CCR due to its decoupling effect on the doublet components. For measurements of dynamics, the use of R1ρ rate constants has practical advantages over the use of CCR rates, and this article reveals factors that have so far been disregarded and which are important for accurate measurements and interpretation. American Chemical Society2016 eng Physical and Theoretical ChemistryMaterials ChemistrySurfacesCoatings and Films The Journal of Physical Chemistry B 1520-6106 1520-520710.1021/acs.jpcb.6b06129 120348905-8913 yes Kurauskas, Vilius, Emmanuelle Weber, Audrey Hessel, Isabel Ayala, Dominique Marion, and Paul Schanda. “Cross-Correlated Relaxation of Dipolar Coupling and Chemical-Shift Anisotropy in Magic-Angle Spinning R1ρ NMR Measurements: Application to Protein Backbone Dynamics Measurements.” The Journal of Physical Chemistry B. American Chemical Society, 2016. <a href="https://doi.org/10.1021/acs.jpcb.6b06129">https://doi.org/10.1021/acs.jpcb.6b06129</a>. Kurauskas, Vilius, et al. “Cross-Correlated Relaxation of Dipolar Coupling and Chemical-Shift Anisotropy in Magic-Angle Spinning R1ρ NMR Measurements: Application to Protein Backbone Dynamics Measurements.” The Journal of Physical Chemistry B, vol. 120, no. 34, American Chemical Society, 2016, pp. 8905–13, doi:<a href="https://doi.org/10.1021/acs.jpcb.6b06129">10.1021/acs.jpcb.6b06129</a>. Kurauskas V, Weber E, Hessel A, Ayala I, Marion D, Schanda P. 2016. Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements. The Journal of Physical Chemistry B. 120(34), 8905–8913. Kurauskas, V., Weber, E., Hessel, A., Ayala, I., Marion, D., & Schanda, P. (2016). Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements. The Journal of Physical Chemistry B. American Chemical Society. <a href="https://doi.org/10.1021/acs.jpcb.6b06129">https://doi.org/10.1021/acs.jpcb.6b06129</a> V. Kurauskas, E. Weber, A. Hessel, I. Ayala, D. Marion, P. Schanda, The Journal of Physical Chemistry B 120 (2016) 8905–8913. Kurauskas V, Weber E, Hessel A, Ayala I, Marion D, Schanda P. Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements. The Journal of Physical Chemistry B. 2016;120(34):8905-8913. doi:<a href="https://doi.org/10.1021/acs.jpcb.6b06129">10.1021/acs.jpcb.6b06129</a> V. Kurauskas, E. Weber, A. Hessel, I. Ayala, D. Marion, and P. Schanda, “Cross-correlated relaxation of dipolar coupling and chemical-shift anisotropy in magic-angle spinning R1ρ NMR measurements: Application to protein backbone dynamics measurements,” The Journal of Physical Chemistry B, vol. 120, no. 34. American Chemical Society, pp. 8905–8913, 2016. 84532020-09-18T10:07:07Z2021-01-12T08:19:22Z