ISSN:
1572-9699
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A dextran-hydrolysing enzyme from Lipomyces lipofer IGC 4042 was purified from the supernatant of cultures grown on a mineral medium with dextran, by ultrafiltration and gel filtration on Bio Gel A-0.5 m. This preparation gave only one band by disc gel electrophoresis. Glucose was the only product of dextran hydrolysis. Optimum pH and temperature for the activity of the enzyme were pH 4.5–5.0 and 45°C, respectively. The enzyme was most stable over a pH range of 4.5–6.0, and after 2 hours at 50°C maintained over 60% of its original activity. The molecular weight was 29,000 daltons and the isoelectric point was at pH 7. Km (45°C, pH 5) for dextran T-40 was 1.2×10−5 M. Glucose inhibited the enzyme competitively with a Ki (45°C, pH 5) of 0.5 mM.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00393677
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