The domains in gammaB-crystallin: identical fold-different stabilities.
J Mol Biol
; 269(2): 260-9, 1997 Jun 06.
Article
em En
| MEDLINE
| ID: mdl-9191069
ABSTRACT
gammaB-crystallin from vertebrate eye lens is an all beta-sheet two-domain protein with a high degree of intrachain symmetry. Its N and C-terminal domains show high levels of sequence similarity and structural identity. In natural gammaB-crystallin, the domains fold independently. The recombinantly expressed isolated domains are stable monomeric proteins, which do not associate spontaneously to form a gammaB-like dimer. In contrast to their identical folding topology, the two domains obviously follow different folding mechanisms. While the two-state model is valid for the C-terminal domain, the folding behaviour of the N-terminal domain is more complex. The stability of the C-terminal domain is strongly dependent on pH. At pH 2, the C-terminal domain in its isolated form is significantly less stable than within the gammaB-molecule. In contrast, the isolated N-terminal domain does not differ in its stability from the N-terminal domain in wild-type gammaB-crystallin. The strongly decreased stability of the C-terminal domain at acid pH allowed a dissection of the intrinsic stabilities of the domains and their interactions in gammaB-crystallin. At pH 2, domain interactions contribute -16 kJ/mol to the overall stability of gammaB-crystallin.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Dobramento de Proteína
/
Cristalinas
Idioma:
En
Revista:
J Mol Biol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Alemanha