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)...
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| Vydané v: | Biochemical journal Ročník 117; číslo 4; s. 667 |
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| Hlavní autori: | , |
| Médium: | Journal Article |
| Jazyk: | English |
| Vydavateľské údaje: |
England
01.05.1970
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| Predmet: | |
| ISSN: | 0264-6021 |
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| Shrnutí: | 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. |
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| Bibliografia: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 0264-6021 |
| DOI: | 10.1042/bj1170667 |