Mise au point Modulations conformationnelles du repliement β en serie peptidique et pseudopeptidique

Aubry, Alexia; Boussard, G.; Cung, Manh Thông; Marraud, M.; Vitoux, B.

doi:10.1051/jcp/1988850345

Cited by 35 publications

(16 citation statements)

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“…Constrained amino acids may be exploited in the construction of backbone‐modified peptides to impart highly localized biases that may be used to explore bioactive conformations (1–11). In this connection, inter alia we investigated the fundamental aspects of these effects for a number of chiral, C α ‐methylated α‐amino acids (8) and compared them with some other analogs, notably Aib, the achiral prototypical residue of this family (4–7,9).…”

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confidence: 99%

(αMe)Nva: stereoselective syntheses and preferred conformations of selected model peptides

Moretto¹,

Peggion²,

Formaggio³

et al. 2000

The Journal of Peptide Research

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Using different stereoselective chemical and chemoenzymatic approaches we synthesized the chiral, Calpha-methylated alpha-amino acid L-(alphaMe)Nva with a short, linear side-chain. A set of terminally protected model peptides to the pentamer level containing either (alphaMe)Nva or Nva in combination with Ala and/or Aib was prepared using solution methods and characterized fully. Two (alphaMe)Nva peptides were also synthesized using side-chain hydrogenation of the corresponding Calpha-methyl, Calpha-allylglycine (Mag) peptides. A detailed solution and crystal-state conformational analysis based on FT-IR absorption, 1H NMR and X-ray diffraction techniques allowed us to define that: (i) (alphaMe)Nva is an effective beta-turn and 3(10)-helix former; and (ii) the relationship between (alphaMe)Nva chirality and the screw sense of the turn/helix formed is that typical of protein amino acids, i.e. L-(alphaMe)Nva induces the preferential formation of right-handed folded structures. In more general terms, this study reinforced previous conclusions that peptides based on alpha-amino acids with a Calpha-methyl substituent and a Calpha-linear alkyl substituent are characterized by a strong tendency to fold into turn and helical structures.

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confidence: 99%

(αMe)Nva: stereoselective syntheses and preferred conformations of selected model peptides

Moretto¹,

Peggion²,

Formaggio³

et al. 2000

The Journal of Peptide Research

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“…As for the effects of the replacement of the amide O with S on the conformation of an α‐peptide chain, early studies (before 1988), owing to the longer C′S bond and larger van der Waals radius of S, highlighted the impossibility to incorporate a thionamide group into α‐helices and pleated β‐sheets of peptides (at variance with β‐turn elements]) without inducing a significant distortion in their secondary structures. The major effect is noted at high values for the ϕ and ψ backbone torsion angles.…”

Section: Resultsmentioning

confidence: 99%

“…Since their discovery, thionamides were shown to be among the most versatile organic substrates, particularly in the area of heterocyclic compound formation. In the last 60 years, the study of their chemical properties has been generating an upsurge in interest for this quasi ‐isosteric amide carbonyl replacement …”

Section: Introductionmentioning

confidence: 99%

Endothioxopeptides: A conformational overview

et al. 2016

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Although thionamides would have been first prepared two centuries ago and their chemical and spectroscopic properties extensively investigated, only much more recently (since about 1985) a well deserved but still insufficient attention has been paid to their endothioxopeptide subfamily which nonetheless currently represents a rapidly emerging area of great scientific interest in the broader field of foldameric compounds based on biologically relevant building blocks. After two brief sections offering information on the unfortunately still limited number of endothioxopeptides discovered from natural sources but also on the impressive advancements registered in the last few years in their synthetic methods, this review article outlines the results of a detailed literature survey on the ongoing great, but not systematic, progress related to the conformational consequences generated by incorporating one (or more) thionamide group(s) into a polypeptide chain. Finally, a short discussion of the growing, but still in its infancy, class of the endoselenoxopeptide congeners is also presented.

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“…The Z-protected L-Ala and Aib tert-butyl esters were prepared by treatment of the corresponding N-protected amino acids with isobutene in methylene chloride in the presence of a catalytic amount of sulphuric acid. The symmetrical anhydride (Z-Aib) 2 O was synthesized in acetonitrile by intermolecular dehydration of the N-protected amino acid with N-ethyl,N%-(3-dimethylaminopropyl)-carbodiimide in a 2:1 molar ratio. L-Ala-L-Ala, L-Ala-Ac 11 c, Ac 11 c-L-Ala, Ac 11 c-Aib, Ac 11 c-Ac 11 c and Ac 11 c-NH alkyl peptide (amide) bond formation was obtained in methylene chloride using N-ethyl,N%-(3-dimethylaminopropyl)-carbodiimide in the presence of 7-aza-1-hydroxy-1,2,3-benzotriazole as the hydroxylamine-based additive [28].…”

Section: Synthesis Of Ac 11 C and Its Derivatives And Peptidesmentioning

confidence: 99%

Preferred conformation of peptides based on cycloaliphatic C?,?-disubstituted glycines: 1-amino-cycloundecane-1-carboxylic acid (Ac11c)

et al. 2000

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Two complete series of N‐protected oligopeptide esters to the pentamer level from 1‐amino‐cycloundecane‐1‐carboxylic acid (Ac11c), an α‐amino acid conformationally constrained through a medium‐ring Cαi↔Cαi cyclization, and either the L‐Ala or Aib residue, along with the N‐protected Ac11c monomer and homo‐dimer alkylamides, have been synthesized by solution methods and fully characterized. The preferred conformation of these model peptides has been assessed in deuterochloroform solution by FT‐IR absorption and 1H‐NMR techniques. Furthermore, the molecular structures of one derivative (Z‐Ac11c‐OH) and two peptides (the tripeptide ester Z‐Aib‐Ac11c‐Aib‐OtBu and the pentapeptide ester Z‐Ac11c‐(Aib)2‐Ac11c‐Aib‐OtBu) have been determined in the crystal state by X‐ray diffraction. The experimental results support the view that β‐bends and 310‐helices are preferentially adopted by peptides rich in Ac11c, the second largest cycloaliphatic Cα,α‐disubstituted glycine known. This investigation has allowed the authors to approach the completion of a detailed conformational analysis of the whole 1‐amino‐cycloalkane‐1‐carboxylic acid (Acnc, with n=3–12) series, which represents the prerequisite for their recent proposal of the ‘Acnc scan’ concept. Copyright © 2000 European Peptide Society and John Wiley & Sons, Ltd.

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Mise au point Modulations conformationnelles du repliement β en serie peptidique et pseudopeptidique

Cited by 35 publications

References 0 publications

(αMe)Nva: stereoselective syntheses and preferred conformations of selected model peptides

(αMe)Nva: stereoselective syntheses and preferred conformations of selected model peptides

Endothioxopeptides: A conformational overview

Preferred conformation of peptides based on cycloaliphatic C?,?-disubstituted glycines: 1-amino-cycloundecane-1-carboxylic acid (Ac11c)

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