caa a22 4500 477136095 CHVBK 20180405111718.0 cr unu---uuuuu 170330e19971201xx s 000 0 eng 10.1023/A:1018365815186 doi (NATIONALLICENCE)springer-10.1023/A:1018365815186 Off-resonance rf fields in heteronuclear NMR: Application to the study of slow motions [Elektronische Daten] [Sophie Zinn-Justin, Patrick Berthault, Marc Guenneugues, Hervé Desvaux] The advantages of using off-resonance rf fields in heteronuclear self-relaxation experiments are explored on a fully 15N-enriched protein. It is firstly shown that in the absence of slow motions the longitudinal and transverse 15N self-relaxation rate values derived with this method are in agreement with the ones measured by the classical inversion-recovery and Carr-Purcell-Meiboom-Gill (CPMG) sequences, respectively. Secondly, by comparing the 15N transverse self-relaxation rates obtained by the proposed off-resonance sequence and by the CPMG sequence, 11 residues out of the 61 of toxin α are shown to exhibit a chemical exchange phenomenon in water on a time scale ranging from 1 µs to 100 ms. By varying the effective field amplitude, chemical exchange processes involving these residues are measured and the corresponding correlation times are evaluated without having assumed any motion model. Similar, though less precise, results are given by the analysis of the 15N off-resonance self-relaxation rates on the basis of the Lipari-Szabo model to describe the fast internal dynamics of toxin α. Kluwer Academic Publishers, 1997 Heteronuclear relaxation nationallicence Protein dynamics nationallicence Chemical exchange nationallicence Off-resonance field nationallicence 15N NMR nationallicence Toxin nationallicence Zinn-Justin Sophie Département d'Ingénierie et d'Etude des Protéines, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut Berthault Patrick Service de Chimie Moléculaire, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut Guenneugues Marc Département d'Ingénierie et d'Etude des Protéines, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut Desvaux Hervé Service de Chimie Moléculaire, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut Journal of Biomolecular NMR Kluwer Academic Publishers 10/4(1997-12-01), 363-372 0925-2738 10:4<363 1997 10 10858 https://doi.org/10.1023/A:1018365815186 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018365815186 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zinn-Justin Sophie Département d'Ingénierie et d'Etude des Protéines, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut NATIONALLICENCE 700 1- Berthault Patrick Service de Chimie Moléculaire, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut NATIONALLICENCE 700 1- Guenneugues Marc Département d'Ingénierie et d'Etude des Protéines, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut NATIONALLICENCE 700 1- Desvaux Hervé Service de Chimie Moléculaire, CEA Saclay, F-91191, Gif sur Yvette Cedex, France aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Kluwer Academic Publishers 10/4(1997-12-01), 363-372 0925-2738 10:4<363 1997 10 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer