Role of positions e and g in the fibrous assembly formation of an amphipathic α-helix-forming polypeptide.
Biopolymers
; 102(3): 260-72, 2014 May.
Article
em En
| MEDLINE
| ID: mdl-24615557
ABSTRACT
We previously characterized α3, a polypeptide that has a three times repeated sequence of seven amino acids (abcdefg LETLAKA) and forms fibrous assemblies composed of amphipathic α-helices. Upon comparison of the amino acid sequences of α3 with other α-helix forming polypeptides, we proposed that the fibrous assemblies were formed due to the alanine (Ala) residues at positions e and g. Here, we characterized seven α3 analog polypeptides with serine (Ser), glycine (Gly), or charged residues substituted for Ala at positions e and g. The α-helix forming abilities of the substituted polypeptides were less than that of α3. The polypeptides with amino acid substitutions at position g and the polypeptide KEα3, in which Ala was substituted with charged amino acids, formed few fibrous assemblies. In contrast, polypeptides with Ala replaced by Ser at position e formed ß-sheets under several conditions. These results show that Ala residues at position e and particularly at position g are involved in the formation of fibrous assemblies.
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01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article