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Accurate measurement of (3)J(HNH?) couplings in small or disordered proteins from WATERGATE-optimized TROSY spectra.

ABSTRACT: Provided that care is taken in adjusting the WATERGATE element of a (1)H-(15)N TROSY-HSQC experiment, such that neither the water magnetization nor the (1)H(?) protons are inverted by its final 180° pulse, (3)JHNH? couplings can be measured directly from splittings in the (1)H dimension of the spectrum. With band-selective (1)H decoupling, very high (15)N resolution can be achieved. A complete set of (3)JHNH? values, ranging from 3.4 to 10.1 Hz was measured for the 56-residue third domain of IgG-binding protein G (GB3). Using the H-N-C(?)-H(?) dihedral angles extracted from a RDC-refined structure of GB3, (3)JHNH? values predicted by a previously parameterized Karplus equation agree to within a root-mean-square deviation (rmsd) of 0.37 Hz with the experimental data. Values measured for the Alzheimer's implicated A?(1-40) peptide fit to within an rmsd of 0.45 Hz to random coil (3)JHNH? values.

SUBMITTER: Roche J

PROVIDER: S-EPMC4744140 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

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Accurate measurement of (3)J(HNHα) couplings in small or disordered proteins from WATERGATE-optimized TROSY spectra.

Roche Julien J Ying Jinfa J Bax Ad A

Journal of biomolecular NMR 20151210 1

Provided that care is taken in adjusting the WATERGATE element of a (1)H-(15)N TROSY-HSQC experiment, such that neither the water magnetization nor the (1)H(α) protons are inverted by its final 180° pulse, (3)JHNHα couplings can be measured directly from splittings in the (1)H dimension of the spectrum. With band-selective (1)H decoupling, very high (15)N resolution can be achieved. A complete set of (3)JHNHα values, ranging from 3.4 to 10.1 Hz was measured for the 56-residue third domain of IgG ...[more]

PMID: 26660434

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