We describe a new NMR experimental scheme that allows the direct determination of the dynamic frequency shift induced by chemical shift anisotropy/dipolar interaction (CSA/DD) cross-correlations in 15N-enriched proteins. Its principle consists of comparing two rates of polarisation transfer between the amide proton and nitrogen. The first rate, which is independent of the dynamic frequency shift, is based on a selective Hartmann-Hahn coherence transfer. The second rate, which depends on the dynamic frequency shift, is based on a free evolution of the transverse magnetisation. We report experimental validation of this approach by measuring the average dynamic frequency shift due to CSA/DD cross-correlations in the calcium-binding protein D9k. The method may also be applicable to the measurement of dynamic frequency shift induced by cross-correlations between the Curie spin and dipolar interactions.
Direct measurement of dynamic frequency shift induced by cross-correlation in 15N-enriched proteins / H.Desvaux; R.Kuemmerle; J.Kowalewski; C.Luchinat; I.Bertini. - In: CHEMPHYSCHEM. - ISSN 1439-4235. - STAMPA. - 5:(2004), pp. 959-965. [10.1002/cphc.200301034]
Direct measurement of dynamic frequency shift induced by cross-correlation in 15N-enriched proteins
LUCHINAT, CLAUDIO;BERTINI, IVANO
2004
Abstract
We describe a new NMR experimental scheme that allows the direct determination of the dynamic frequency shift induced by chemical shift anisotropy/dipolar interaction (CSA/DD) cross-correlations in 15N-enriched proteins. Its principle consists of comparing two rates of polarisation transfer between the amide proton and nitrogen. The first rate, which is independent of the dynamic frequency shift, is based on a selective Hartmann-Hahn coherence transfer. The second rate, which depends on the dynamic frequency shift, is based on a free evolution of the transverse magnetisation. We report experimental validation of this approach by measuring the average dynamic frequency shift due to CSA/DD cross-correlations in the calcium-binding protein D9k. The method may also be applicable to the measurement of dynamic frequency shift induced by cross-correlations between the Curie spin and dipolar interactions.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.