caa a22 4500 477136060 CHVBK 20190328074419.0 cr unu---uuuuu 170330e19971201xx s 000 0 eng 10.1023/A:1018373601391 doi (NATIONALLICENCE)springer-10.1023/A:1018373601391 Determination of backbone nitrogen-nitrogen J correlations in proteins [Elektronische Daten] [Karsten Theis, Andrew Dingley, Astrid Hoffmann, James Omichinski, Stephan Grzesiek] Recently, a quantitative J correlation technique has been presented which makes use of homonuclear Hartmann-Hahn cross-polarization (TOCSY) to measure 3JC′C′ in proteins isotopically enriched with 13C [Grzesiek, S. and Bax, A. (1997) J. Biomol. NMR, 9, 207-211]. Since homonuclear Hartmann-Hahn is twice as fast as conventional COSY transfer, this method is much less sensitive to transverse relaxation, which is the principal limiting factor in achieving long-range J-coupling correlations in macromolecules. Here we describe a similar experiment which is used to measure3 JNN coupling constants between sequential amide15 N nuclei in the backbone of ubiquitin. As expected from the low magnetic moment of 15N, the 3JNN coupling constants are exceedingly small, with values between 0.14 and 0.36 Hz for residues in β-conformations and values below 0.15 Hz for residues in α-conformations. In contrast to what is expected from a Karplus-type dependence on the backbone angle ψ, large differences in the values of3 JNN are observed for a number of residues with very similar backbone ψ angles. A quantitative description of statistical and systematic errors, in particular of relaxation effects during the TOCSY transfer, shows that these differences are highly significant. Kluwer Academic Publishers, 1997 Nitrogen-nitrogen J coupling nationallicence HOHAHA nationallicence TOCSY nationallicence ψ Angle nationallicence Relaxation nationallicence Ubiquitin nationallicence Theis Karsten Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut Dingley Andrew Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut Hoffmann Astrid IBI-2, Institute of Structural Biology, Forschungszentrum Jülich, D-52425, Jülich, Germany aut Omichinski James IBI-2, Institute of Structural Biology, Forschungszentrum Jülich, D-52425, Jülich, Germany aut Grzesiek Stephan Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut Journal of Biomolecular NMR Kluwer Academic Publishers 10/4(1997-12-01), 403-408 0925-2738 10:4<403 1997 10 10858 https://doi.org/10.1023/A:1018373601391 text/html Onlinezugriff via DOI 1 brief-communication jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018373601391 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Theis Karsten Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Dingley Andrew Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 700 1- Hoffmann Astrid IBI-2, Institute of Structural Biology, Forschungszentrum Jülich, D-52425, Jülich, Germany aut NATIONALLICENCE 700 1- Omichinski James IBI-2, Institute of Structural Biology, Forschungszentrum Jülich, D-52425, Jülich, Germany aut NATIONALLICENCE 700 1- Grzesiek Stephan Institute of Physical Biology, Heinrich-Heine-Universität, D-40225, Düsseldorf, Germany aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Kluwer Academic Publishers 10/4(1997-12-01), 403-408 0925-2738 10:4<403 1997 10 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer