Alpha-lactalbumin induces bovine milk beta 1,4-galactosyltransferase to utilize UDP-GalNAc.
J Biol Chem
; 270(31): 18447-51, 1995 Aug 04.
Article
em En
| MEDLINE
| ID: mdl-7629170
ABSTRACT
We now report that alpha-lactalbumin (alpha-LA) has a novel effect on bovine milk UDP-GalGlcNAc-beta 1,4-galactosyltransferase (beta 1,4-GT) and induces the enzyme to efficiently utilize UDP-GalNAc as a donor. In the presence of alpha-LA the enzyme transfers GalNAc to free GlcNAc to produce GalNAc beta 1-4GlcNAc at a rate 55% of that compared to the rate when UDP-Gal is the donor in the absence of alpha-LA. The stimulation by alpha-LA is dependent on the concentrations of alpha-LA, acceptor, and sugar nucleotide. Interestingly, beta 1,4-GT is unable to transfer Gal-NAc to Glc with or without alpha-LA. alpha-LA also stimulates the transfer of GalNAc from UDP-GalNAc to various chitin oligomers, although the degree of stimulation decreases as the acceptor size increases. Thus, bovine milk beta 1,4-GT has an inherent ability to utilize two different sugar nucleotides and the sugar nucleotide preference is regulatable by alpha-LA.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Uridina Difosfato N-Acetilgalactosamina
/
N-Acetil-Lactosamina Sintase
/
Leite
/
Lactalbumina
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Estados Unidos