Bovine beta-lactoglobulin: interaction studies with palmitic acid.
Protein Sci
; 9(7): 1347-56, 2000 Jul.
Article
en En
| MEDLINE
| ID: mdl-10933500
Bovine beta-lactoglobulin (BLG) in vivo has been found complexed with fatty acids, especially palmitic and oleic acid. To elucidate the still unknown structure-function relationship in this protein, the interactions between 13C enriched palmitic acid (PA) and BLG were investigated by means of one-, two-, and three-dimensional NMR spectroscopy in the pH range 8.4-2.1. The NMR spectra revealed that at neutral pH the ligand is bound within the central cavity of BLG, with the methyl end deeply buried within the protein. The analysis of 13C spectra of the holo protein revealed the presence of conformational variability of bound PA carboxyl end in the pH range 8.4-5.9, related to the Tanford transition. The release of PA starts at pH lower than 6.0, and it is nearly complete at acidic pH. This finding is relevant in relation to the widely reported hypothesis that this protein can act as a transporter through the acidic gastric tract. Ligand binding and release is shown to be completely reversible over the entire pH range examined, differently from other fatty acid binding proteins whose behavior is analyzed throughout the paper. The mode of interaction of BLG is compatible with the proposed function of facilitating the digestion of milk fat during the neonatal period of calves.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ácido Palmítico
/
Lactoglobulinas
Límite:
Animals
Idioma:
En
Revista:
Protein Sci
Asunto de la revista:
BIOQUIMICA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Italia
Pais de publicación:
Estados Unidos