14-Helical folding in a cyclobutane-containing β-tetrapeptide
The efficient synthesis of tetrapeptide 5 containing, in alternation, cyclobutane and β-alanine residues is described. NMR experiments both at low temperature in CDCl3 and at 298 K in DMSO-d6 solutions show the contribution of a strong hydrogen bond in the folded major conformation of 5. Temperature...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2004 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/137894 |
| Acceso en línea: | http://hdl.handle.net/11336/137894 |
| Access Level: | acceso abierto |
| Palabra clave: | helical folding peptides https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Sumario: | The efficient synthesis of tetrapeptide 5 containing, in alternation, cyclobutane and β-alanine residues is described. NMR experiments both at low temperature in CDCl3 and at 298 K in DMSO-d6 solutions show the contribution of a strong hydrogen bond in the folded major conformation of 5. Temperature coefficients and diffusion times point out a hydrogen bond involving the NH proton from the cyclobutane residue 1 whereas NOEs manifest the high rigidity of the central fragment of the molecule and are compatible with a 14-membered macrocycle. Theoretical calculations predict a most stable folded conformation corresponding to a 14-helix stabilized by a hydrogen bond between NH10 in the first residue and OC25 in the third residue. This structure remains unaltered during the molecular dynamics simulation at 298 K in chloroform. All these results provide evidence for a 14-helical folding and reveal the ability of cis-2-aminocyclobutane carboxylic acid residues to promote folded conformations when incorporated into β-peptides. |
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