Cross-talk among structural domains of human DBP upon binding 25-hydroxyvitamin D.
Biochem Biophys Res Commun
; 365(4): 746-50, 2008 Jan 25.
Article
em En
| MEDLINE
| ID: mdl-18035050
ABSTRACT
Serum vitamin D-binding protein (DBP) is structurally very similar to serum albumin (ALB); both have three distinct structural domains and high cysteine-content. Yet, functionally they are very different. DBP possesses high affinity for vitamin D metabolites and G-actin, but ALB does not. It has been suggested that there may be cross-talk among the domains so that binding of one ligand may influence the binding of others. In this study we have employed 2-p-toluidinyl-6-sulfonate (TNS), a reporter molecule that fluoresces upon binding to hydrophobic pockets of DBP. We observed that recombinant domain III possesses strong binding for TNS, which is not influenced by 25-hydroxyvitamin D(3) (25-OH-D(3)), yet TNS fluorescence of the whole protein is quenched by 25-OH-D(3). These results provide a direct evidence of cross-talk among the structural domains of DBP.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina D
/
Proteína de Ligação a Vitamina D
Limite:
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos