Hydrolysis of beta-galactosyl ester linkage by beta-galactosidases.
Biosci Biotechnol Biochem
; 64(8): 1702-6, 2000 Aug.
Article
em En
| MEDLINE
| ID: mdl-10993159
ABSTRACT
p-Hydroxybenzoyl beta-galactose (pHB-Gal) was synthesized chemically to examine the hydrolytic activity of beta-galactosyl ester linkage by beta-galactosidases. The enzyme from Penicillium multicolor hydrolyzed the substrate as fast as p-nitrophenyl beta-galactoside (pNP-Gal), a usual substrate with a beta-galactosidic linkage. The enzymes from Escherichia coli and Aspergillus oryzae hydrolyzed pHB-Gal with almost the same rates as pNP-Gal. The enzymes from Bacillus circulans, Saccharomyces fragilis, and bovine liver showed much lower activities. pH-activity profiles, inhibition analysis, and kinetic properties of the enzymic reaction on pHB-Gal suggested that beta-galactosidase had only one active site for hydrolysis of both galactosyl ester and galactoside. The Penicillium enzyme hydrolyzed pHB-Gal in the presence of H218O to liberate galactose containing 18O. This result suggests the degradation occurs between the anomeric carbon and an adjacent O atom in the ester linkage of pHB-Gal.
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Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Beta-Galactosidase
/
Galactose
Limite:
Animals
Idioma:
En
Revista:
Biosci Biotechnol Biochem
Ano de publicação:
2000
Tipo de documento:
Article