Measurement of cross correlation between dipolar coupling and chemical shift anisotropy in the spin relaxation of 13C, 15N-labeled proteins.
We present a simple method for extracting interference effects between chemical shift anisotropy (CSA) and dipolar coupling from spin relaxation measurements in macromolecules, and we apply this method to extracting cross-correlation rates involving interference of amide 15N CSA and 15N-1H dipolar coupling and interference of carbonyl 13C' CSA and 15N-13C' dipolar coupling, in a small protein. A theoretical basis for the interpretation of these rates is presented. While it proves difficult to quantitatively separate the structural and dynamic contributions to these cross-correlation rates in the presence of anisotropic overall tumbling and a nonaxially symmetric chemical shift tensor, some useful qualitative correlations of data with protein structure can be seen when simplifying assumptions are made.
Ghose
R
R
Department of Chemistry, Yale University, New Haven, Connecticut, 06520, USA.
Huang
K
K
Prestegard
J H
JH
D000251:Adenosine Triphosphatases / Q000737:chemistry; D000465:Algorithms; D001426:Bacterial Proteins / Q000737:chemistry; D002247:Carbon Isotopes; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000737:chemistry; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D009587:Nitrogen Isotopes; D011487:Protein Conformation; D011506:Proteins / Q000032:analysis / Q000737:chemistry*; D012399:Rotation
D001426:Bacterial Proteins; D002247:Carbon Isotopes; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D046911:Macromolecular Substances; D009587:Nitrogen Isotopes; D011506:Proteins; D000251:Adenosine Triphosphatases