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Poster communications

Structural characterization of turns in proteins and peptides: new NMR discriminatory parameters by molecular modelling

Abstract : During the last decades, there has been an increased interest in the use of peptides as therapeutics. The knowledge of their 3D structure is crucial to gain a full understanding of partner recognition and binding [1]. Solution NMR coupled to molecular modelling is the privileged method for structural studies of polypeptides and peptides because of their flexibility. It has been shown that helices and turns constitute the preferential recognition patterns of such ligands by their targets. Despite their prevalence in small peptides as well as in globular proteins, turns have always been more challenging to characterize by NMR than helices, because of their non-periodic nature and their heterogenic structures. Indeed, several classes of turns, characterized by a different number of residues and exhibiting different geometries, exist in polypeptide and peptide structures. In the literature, the establishment of the NMR characteristic data (1H-1H distances and scalar couplings) of these different structural motifs is based on a rather ancient analysis of poly-alanine chains [2], which does not take into account all the types of turns or the influence of the nature of the side-chain on these structures.The aim of this study is to provide new NMR structural information, via molecular modelling calculations, to better characterize each type of turns. We focused on β-turns (4 residues) and γ-turns (3 residues), which are the most encountered turns in polypeptide structures.Specific interproton distances were measured in a set of turns selected from PDB X-ray protein structures. New characteristic signatures that may permit to identify, by NMR, all types of β-turns and of γ-turns were found. Particular attention has been paid to the proline structural role in these secondary structures.To complete the analysis, the 3JHN-Hα scalar coupling constant of the central residue(s) of each turn was (were) calculated [3],[4],[5].Taken together, signatures allowing to discriminate different types of β- and γ-turns by different distances and scalar coupling constants were established. These new data will enable to refine the NMR structural description of turns in peptides and might be applied to peptidomimetic studies.References:1. J. A. Robinson Acc. Chem. Res. (2008), 41, 1278-12882. K. Wüthrich, M. Billeter and W. Braun J. Mol. Biol. (1984), 180, 715-7403. A.Pardi, K. M. Billeter and K. Wüthrich J. Mol. Biol. (1984), 180, 741-7514. S. Ludvigsen, K. V. Andersen and F. M. Poulsen J. Mol. Biol. (1991), 217, 731-736
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https://hal-normandie-univ.archives-ouvertes.fr/hal-02542520
Contributor : Laure Guilhaudis <>
Submitted on : Tuesday, April 14, 2020 - 4:55:06 PM
Last modification on : Thursday, July 2, 2020 - 3:29:48 AM

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  • HAL Id : hal-02542520, version 1

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Mattia Migliore, Laure Guilhaudis, Benjamin Lefranc, Jérôme Leprince, Hassan Oulyadi, et al.. Structural characterization of turns in proteins and peptides: new NMR discriminatory parameters by molecular modelling. Congrès du Groupe français des peptides et des protéines (GFPP, 21, 2019), May 2019, Amboise, France. ⟨hal-02542520⟩

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