DNP enhanced frequency-selective TEDOR experiments in bacteriorhodopsin.
We describe a new approach to multiple (13)C-(15)N distance measurements in uniformly labeled solids, frequency-selective (FS) TEDOR. The method shares features with FS-REDOR and ZF- and BASE-TEDOR, which also provide quantitative (15)N-(13)C spectral assignments and distance measurements in U-[(13)C,(15)N] samples. To demonstrate the validity of the FS-TEDOR sequence, we measured distances in [U-(13)C,(15)N]-asparagine which are in good agreement with other methods. In addition, we integrate high frequency dynamic nuclear polarization (DNP) into the experimental protocol and use FS-TEDOR to record a resolved correlation spectrum of the Arg-(13)C(gamma)-(15)N(epsilon) region in [U-(13)C,(15)N]-bacteriorhodopsin. We resolve six of the seven cross-peaks expected based on the primary sequence of this membrane protein.
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Vikram S
VS
Bajaj
Melody L
ML
Mak-Jurkauskas
Marina
M
Belenky
Judith
J
Herzfeld
Robert G
RG
Griffin
D000465:Algorithms; D001436:Bacteriorhodopsins / Q000737:chemistry*; D002247:Carbon Isotopes / Q000737:chemistry; D009587:Nitrogen Isotopes / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D001436:Bacteriorhodopsins