A capillary electrophoretic study on the specificity of beta-galactosidases from Aspergillus oryzae, Escherichia coli, Streptococcus pneumoniae, and Canavalia ensiformis (jack bean).
The specificities of the beta-galactosidases from Aspergillus oryzae, Escherichia coli, Streptococcus pneumoniae, and Canavalia ensiformis (jack bean) have been studied by capillary zone electrophoresis. Various di- and oligosaccharides as well as a biantennary asialo N-glycan were used as substrates. Following enzymatic hydrolysis, the mixtures of substrates and products were derivatized with ethyl 4-aminobenzoate and separated by high-performance capillary electrophoresis in a borate buffer system using uv detection. Baseline separation of the respective peaks was obtained in 4 min, allowing the analysis of a large number of samples. Therefore, initial rates of hydrolysis could be determined. The beta-galactosidase from A. oryzae exhibited minimal activity toward Galbeta1-3GlcNAc. In contrast to the enzyme from S. pneumoniae which is almost specific for beta1-4 linkages, the Aspergillus galactosidase readily hydrolyzed Galbeta1-4GlcNAc and Galbeta1-6GlcNAc. Neither of the four beta-galactosidases acted upon Galbeta1-4(Fucalpha1-3)GlcNAcbeta1-3Galbeta1-4Gl c (lacto-N-fucopentaose III) even though the corresponding nonfucosylated oligosaccharides were good substrates. With the exception of the enzyme from E. coli, the beta-galactosidases degalactosylated a biantennary N-linked oligosaccharide.
Zeleny
R
R
Institut für Chemie der Universität für Bodenkultur, Muthgasse 18, Wien, A-1190, Austria.
Altmann
F
F
Praznik
W
W
D001236:Aspergillus oryzae; D019075:Electrophoresis, Capillary / Q000379:methods*; D004926:Escherichia coli; D007887:Fabaceae; D008970:Molecular Weight; D009844:Oligosaccharides / Q000378:metabolism; D010946:Plants, Medicinal; D013296:Streptococcus pneumoniae; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000378:metabolism*
D009844:Oligosaccharides; D001616:beta-Galactosidase