NOE data demonstrating a compact unfolded state for an SH3 domain under non-denaturing conditions.
J Mol Biol
; 289(3): 619-38, 1999 Jun 11.
Article
em En
| MEDLINE
| ID: mdl-10356333
ABSTRACT
The N-terminal SH3 domain of drk (drkN SH3) is unstable, existing in equilibrium between a folded state (Fexch) and an unfolded state (Uexch) under non-denaturing buffer conditions. Using a15N/2H-labeled sample, long range amide NOEs can be observed in the Uexchstate as a result of reduced relaxation, in some cases correlating protons over 40 residues apart. These long range NOEs disappear upon addition of 2 M guanidinium chloride, demonstrating that there are substantial differences between the Uexchand the guanidine denatured states. Calculations using the long range NOEs of the Uexchstate yield highly compact structures having non-native turns and a non-native buried tryptophan residue. These structures agree with experimental stopped-flow fluorescence data and analytical ultracentrifugation results. Since protein stability depends on the structural and dynamic properties of both the folded and unfolded states, this study provides insights into the stability of the drkN SH3 domain. These results provide the first strong NOE-based evidence for compact unfolded states of proteins and suggest that some unfolded states under physiological conditions have specific interactions leading to compact structures.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Desnaturação Proteica
/
Dobramento de Proteína
/
Domínios de Homologia de src
/
Proteínas de Insetos
/
Proteínas de Drosophila
Idioma:
En
Revista:
J Mol Biol
Ano de publicação:
1999
Tipo de documento:
Article