Ciencia y Tecnología de Materiales >
Instituto de Ciencia de Materiales de Aragón (ICMA) >
(ICMA) Artículos >
Closed Access item Preferred 3D-structure of peptides rich in a severely conformationally restricted cyclopropane analogue of phenylalanine
Borggraeve, Wim M. de
Jiménez, Ana I.
|Keywords:||Chirality, Conformation analysis, NMR spectroscopy, Peptides, X-ray diffraction|
|Citation:||Chemistry - A European Journal 12(1): 251-260 (2005)|
|Abstract:||Terminally blocked, homo-peptide amides of (R,R)-1-amino-2,3-diphenylcyclopropane-1-carboxylic acid (c3diPhe), a chiral member of the family of C-tetrasubstituted -amino acids, from the dimer to the tetramer, and diastereomeric co-oligopeptides of (R,R)- or (S,S)-c3diPhe with (S)-alanine residues to the trimer level were prepared in solution and fully characterized. The synthetic effort was extended to terminally protected co-oligopeptide esters to the hexamer, where c3diPhe residues are combined with achiral -aminoisobutyric acid residues. The preferred conformations of the peptides were assessed in solution by FT-IR absorption, NMR, and CD techniques, and for seven oligomers in the crystal state (by X-ray diffraction) as well. This study clearly indicates that c3diPhe, a sterically demanding cyclopropane analogue of phenylalanine, tends to fold peptides into -turn and 310-helix conformations. However, when c3diPhe is in combination with other chiral residues, the conformation preferred by the resulting peptides is also dictated by the chiral sequence of the amino acid building blocks. The (S,S)-enantiomer of this -amino acid, unusually lacking asymmetry in the main chain, strongly favors the left-handedness of the turn/helical peptides formed.|
|Description:||10 pages, 11 figures, 2 tables.|
|Publisher version (URL):||http://dx.doi.org/10.1002/chem.200500865|
|Appears in Collections:||(ICMA) Artículos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.