We have analyzed a combined use of the two-dimensional nuclear Overhauser effect in the laboratory frame (NOESY) and in the rotating frame (ROESY) to determine interproton distances and correlation time in medium-sized rigid molecules (Davis, 1987). This method can be applied in the intermediate motional regime, 0.2 < ωoτc, < 5, (τc, correlation time, (ωo resonance frequency). Error limits depend on the motional regime and are smallest near ωoτc=1.14. The method was tested on six geminal proton pairs in the bicyclic octapeptide (S-deoxo-γ-[R]-OH-Ile3 amaninamide, Mw =870) for which at 297 K in DMSO, a correlation time of 1.0 ns, with a standard deviation of 0.12 ns, and an interproton distance of 1.87 Å, with standard deviation of 0.04 Å, are obtained. © 1992 ESCOM Science Publishers B.V.
Evaluation of errors of interproton distances and correlation time determined from NMR cross-relaxation rates
ISERNIA, Carla;
1992
Abstract
We have analyzed a combined use of the two-dimensional nuclear Overhauser effect in the laboratory frame (NOESY) and in the rotating frame (ROESY) to determine interproton distances and correlation time in medium-sized rigid molecules (Davis, 1987). This method can be applied in the intermediate motional regime, 0.2 < ωoτc, < 5, (τc, correlation time, (ωo resonance frequency). Error limits depend on the motional regime and are smallest near ωoτc=1.14. The method was tested on six geminal proton pairs in the bicyclic octapeptide (S-deoxo-γ-[R]-OH-Ile3 amaninamide, Mw =870) for which at 297 K in DMSO, a correlation time of 1.0 ns, with a standard deviation of 0.12 ns, and an interproton distance of 1.87 Å, with standard deviation of 0.04 Å, are obtained. © 1992 ESCOM Science Publishers B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.