(13)C-(13)C distance measurements in U-(13)C, (15)N-labeled peptides using rotational resonance width experiment with a homogeneously broadened matching condition.
In this publication, we introduce a version of the rotational resonance width experiment with a homogeneously broadened matching condition. The increase in the bandwidth is achieved by the reduction of the proton decoupling power during mixing, which results in the reduction of zero-quantum relaxation, and broadens the rotational resonance condition. We show that one can achieve recoupling of the carbonyl-aliphatic side chain dipolar interactions band selectively, while avoiding the recoupling of strongly interacting C'-Calpha and C'-Cbeta spin pairs. The attenuation of the multi-spin effects in the presence of short zero-quantum relaxation enables a two-spin approximation to be employed for the analysis of the experimental data. The systematic error introduced by this approximation is estimated by comparing the results with a three-spin simulation. The experiment is demonstrated in [U-(13)C,(15)N]N-acetyl-L-Val-L-Leu dipeptide, where 11 distances, ranging from 2.5 to 6 A, were measured.
Janik
Rafal
R
Department of Physics and Biophysics, Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada N1G 2W1.
Peng
Xiaohu
X
Ladizhansky
Vladimir
V
D000465:Algorithms; D002247:Carbon Isotopes; D004151:Dipeptides / Q000737:chemistry*; D008958:Models, Molecular; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010455:Peptides / Q000737:chemistry*
D002247:Carbon Isotopes; D004151:Dipeptides; C098112:N-acetylvalylleucine; D009587:Nitrogen Isotopes; D010455:Peptides