Stabilization of the fibrous structure of an alpha-helix-forming peptide by sequence reversal.
Biochem Biophys Res Commun
; 331(2): 577-82, 2005 Jun 03.
Article
en En
| MEDLINE
| ID: mdl-15850799
ABSTRACT
The alpha3-peptide, which comprises three repeats of the sequence Leu-Glu-Thr-Leu-Ala-Lys-Ala and forms an amphipathic alpha-helix, is unique among various alpha-helix-forming peptides in that it assembles into fibrous structures that can be observed by transmission electron microscopy. As part of our investigation of the structure-stability relationships of the alpha3-peptide, we synthesized the r3-peptide, whose amino acid sequence is the reverse of that of the alpha3-peptide, and we investigated the effects of sequence reversal on alpha-helix stability and the formation of fibrous structures. Unexpectedly, the r3-peptide formed a more-stable alpha-helix and longer fibers than did the alpha3-peptide. The stability of the r3-peptide helix decreased when the ionic strength of the buffer was increased and when the pH of the buffer was adjusted to 2 or 12. These results suggest that the r3-peptide underwent a "magnet-like" oligomerization and that an increase in the charge-distribution inequality may be the driving force for the formation of fibrous structures.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Péptidos
/
Ingeniería de Proteínas
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2005
Tipo del documento:
Article
País de afiliación:
Japón