Enzymes of Trichomonas foetus. Separation and properties of two beta-galactosidases

The beta-galactosidase activity in extracts of Trichomonas foetus is separable into two fractions by gel filtration on Sephadex G-200. When o-nitrophenyl beta-d-galactoside is used as substrate the first fraction to be eluted, beta-galactosidase 1, has 50 times the activity (units per mg of protein)...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Biochemical journal Jg. 117; H. 4; S. 667
Hauptverfasser: Harrap, G J, Watkins, W M
Format: Journal Article
Sprache:Englisch
Veröffentlicht: England 01.05.1970
Schlagworte:
ISSN:0264-6021
Online-Zugang:Weitere Angaben
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The beta-galactosidase activity in extracts of Trichomonas foetus is separable into two fractions by gel filtration on Sephadex G-200. When o-nitrophenyl beta-d-galactoside is used as substrate the first fraction to be eluted, beta-galactosidase 1, has 50 times the activity (units per mg of protein) of the crude preparation. This fraction is activated by Mn(2+) and Co(2+) and inhibited by Hg(2+) and EDTA. In the presence of Mn(2+) the pH optimum for the hydrolysis of o-nitrophenyl beta-d-galactoside or lactose is 5.8-6.0. beta-Galactosidase 1 is an exoglycosidase that releases beta-linked galactose joined to aliphatic and various carbohydrate aglycones. Hydrolysis is prevented, however, by a substituent on either the subterminal sugar or the terminal non-reducing beta-galactosyl residue in an oligosaccharide. The second fraction, beta-galactosidase 2, is not activated by metal ions or inhibited by EDTA and has a broad pH optimum from 4.5 to 6.0.
Bibliographie:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0264-6021
DOI:10.1042/bj1170667