Determination of Chemical Shift Anisotropy Tensors of Carbonyl Nuclei in Proteins through Cross‐Correlated Relaxation in NMR

Abstract

The principal components and orientations of the chemical shift anisotropy (CSA) tensors of nearly all 13C carbonyl nuclei in a small protein have been determined in isotropic solution by a combination of three complementary cross-correlation measurements.

Temperature dependence of protein backbone motion from carbonyl 13C and amide 15N NMR relaxation

“…The average orientation and the traceless components of the CSA tensor measured in solution [34,36,37] and in solid-state [38][39][40][41][42][43] have been reported. Our calculations were based on the average 13 C 0 CSA values estimated from residual chemical shifts reported by Cornilescu and Bax [34], where b = 38°, r xx = À74.7 ppm, r yy = À11.8 ppm, and r zz = 86.5 ppm.…”

Detection of correlated dynamics on multiple timescales by measurement of the differential relaxation of zero- and double-quantum coherences involving sidechain methyl groups in proteins

“…These measurements have revealed the existence of anisotropic motion in the protein backbone [3] and have allowed the estimation of hitherto inaccessible backbone dihedral angles [4][5][6][7]. They have also provided the means to determine the chemical shift tensor for backbone amide 15 N [8][9][10][11], 13 C a [12], and carbonyl 13 C 0 [13,14] nuclei in solution.…”

Parameterization of Peptide 13C Carbonyl Chemical Shielding Anisotropy in Molecular Dynamics Simulations

“…[1][2][3][4] The 13 C' CSA relaxation of proteins in particular is increasingly used, in addition to NH dipolar relaxation, to help characterize the dynamical processes of the protein backbone. [5][6][7][8][9][10][11] However, it was realized that the 13 C' CSA is not constant for the different amino acids in a protein. [5,[9][10][11][12][13] In particular, the central component s yy and the angle of the s zz principal axis can vary by 20 ppm and 208, respectively, over the protein sequence.…”