Assignment of carbonyl carbons and sequence analysis in peptides by heteronuclear shift correlation via small coupling constants with broadband decoupling in t1 (COLOC)

Kessler, Horst; Griesinger, Christian; Zarbock, Jutta; Loosli, Hans‐Rudolf

doi:10.1016/0022-2364(84)90136-7

Cited by 437 publications

(141 citation statements)

References 4 publications

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“…The COLOC experiment had recently been published [7] when we started this work; however a COLOC spectrum obtained at 328 K and 4.7 T displayed correlations corresponding to only some of the couplings ob served in the proton-coupled carbon spectrum. In contrast inverse HMBC experiments [8] per formed at ambient tem perature and 11.7 T dis played more correlations; with the delay r2 set to 70 ms the largest correlations should arise from long-range C,H coupling constants of ca.…”

Section: Resultsmentioning

confidence: 99%

Revised Structure of Haemoventosin

Rycroft

Connolly

Huneck

et al. 1995

Zeitschrift Für Naturforschung B

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Section: Resultsmentioning

confidence: 99%

Revised Structure of Haemoventosin

Rycroft

Connolly

Huneck

et al. 1995

Zeitschrift Für Naturforschung B

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“…The relayed coherence transfer (RCT) method was adapted from Bolton [26], the I3C-lH and "N-'H shift correlations, which included 'H homonuclear decoupling in the fl domain, from Bax [27], and the 13C-lH shift correlation via long-range coupling from Kessler et al [28]. The peaks in the final 2D spectra were obtained in the absolute value mode.…”

Section: Methodsmentioning

confidence: 99%

The conformation of gramicidin A in dimethylsulphoxide solution. A full analysis of the one- and two-dimensional 1H, 13C, and 15N nuclear-magnetic-resonance spectra

et al. 1987

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The combined application of one-and two-dimensional high-field NMR techniques has led to the first assignment of the 'H, 13C, and I5N spectra of the pentadecapeptide gramicidin A in dimethylsulphoxide solution. The 62.9-MHz and 100.6-MHz '."C spin-lattice relaxation times and 13C-{1H} NOE factors for the backbone a carbons have been analysed in the 'model-free' approach to give a single correlation time (7,) for isotropic overall molecular motion and an order parameter and internal correlation time for each C"H group in the backbone. The relatively high and constant values for the order parameter along the backbone indicate a degree of ordering of the structure, while the internal correlation times show that internal motions are progressively more rapid towards the N terminus. Veatch and Blout [21] relied largely upon CD spectra in proposing that gramicidin A in organic solvents probably exists as interconverting intertwined helical dimers, although these CD studies did not include (CH&SO as solvent due to its absorption in the wavelength region of interest. '."C-NMR relaxation rates were interpreted by Fossel et al. [8] as indicating that gramicidin A is a structured dimer in methanol solution, but a random-coil monomer in (CH3)2S0 solution. Rondelez and Litster [12] used light-scattering studies to show that the peptide exists in a dimeric state in methanol and dioxane solutions and as a monomer in (CH3)2S0 solution at concentrations in the range 18 -50 mg/ml. Recent work by Arseniev et al. [7] used the inter-proton nuclear Overhauser enhancement (NOE) effect in the 'H-NMR spectra of gramicidin A to show an anti-parallel n,z?$ double-helical conformation for the dimeric species in dioxane solution.

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“…Finally, determination of the regioselectivity of the non symmetric ozonolysis was achieved by a C-H correlation via long range coupling (COLOC) 8 that clearly showed a cross peak between the H-10 and C-carboxylic, the cross peaks between C-11 and H-10 (J 2 ) and between C-13 and H-2 (J 3 ) added further support to the assignment. The 13 C data is summarized in Table 1.…”

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confidence: 88%