Two model tetrapeptides containing bicyclic analogues of either D- or L-proline were synthesised and their conformational properties were studied by NMR in different solvent systems and by molecular modelling techniques. Compound 1, with the bicyclic D-proline mimetic in the i+1 position, generated a unique trans isomer, and the peptide showed a well organised structure, in accordance with the tendency of Dproline to act as a good turn inducer with respect to its enantiomer. Peptide 2 displayed structures equilibrating from type I,II to type VI β-turns, thus confirming the hypothesised relationship between the chirality of BGS/Bgs and proline enantiomers on nucleating compact turns. Moreover, such behaviour suggested a tool for peptidomimetic design of reverse turn peptides containing BGS/Bgs bicyclic proline mimetics, as the choice of chirality might influence the generation either of compact γ- and β-turns or of flexible equilibrating reverse turn structures. The effect of solvent on conformational behaviour was also studied.
|Titolo:||Solvent-Dependent Conformational Behaviour of Model Tetrapeptides Containing a Bicyclic Proline Mimetic|
POTENZA, DONATELLA (Secondo)
|Parole Chiave:||Conformational analysis; NMR spectroscopy; Peptidomimetics; Proline; Reverse turn|
|Settore Scientifico Disciplinare:||Settore CHIM/06 - Chimica Organica|
|Data di pubblicazione:||2004|
|Digital Object Identifier (DOI):||10.1002/ejoc.200400359|
|Appare nelle tipologie:||01 - Articolo su periodico|