Importance of polypeptide chain length for the correct local folding of a ß-sheet protein.
Biophys Chem
; 168-169: 40-7, 2012 Jul.
Article
em En
| MEDLINE
| ID: mdl-22820703
ABSTRACT
Equine ß-lactoglobulin is a 162-residue ß-sheet protein. A partially folded form of equine ß-lactoglobulin contains a ß-hairpin and an α-helix. The ß-hairpin converts into non-native α-helices at temperatures <0°C. CHIBL, a truncated equine ß-lactoglobulin (residues 88-142), contains the low-temperature α-helical structure even at room temperature, indicating that the interactions responsible for the stability of the ß-hairpin reside in non-CHIBL residues. For the study reported herein, we characterized two truncated mutants and their leucine103 â proline103 variants to identify residues that stabilize the ß-hairpin. The dependence of their circular dichroism spectra on chloride ion concentration and temperature revealed that the ability to transition from the non-native α-helices to the ß-hairpin depends on the polypeptide chain length and improves as the chain length increases despite the apparent absence of any ordered structure in the extended sequences.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lactoglobulinas
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article