ISSN:
1432-2056
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary We have found out that cell-free extracts from frozen krill decompose many oligo-and polysacharides, particularly with (1→3)-β-and (1→4)-β-linkages. Two individual proteins have very high activity with laminaran as the substrate. One of them has been isolated and purified 980-fold. Polyacrylamide-gel electrophoresis of purified preparation of krill (1→3)-β-glucanase [(1→3)-β-D-glucan glucanohydrolase, EC 3.2.1.6] demonstrated that it was slightly contaminated by one protein band inactive in laminaran hydrolysis. Studies on the hydrolysis of different substrates showed that the enzyme was able to break down only (1→3)-β-D-linkages by an endo-splitting mechanism. Glucono-δ-lactone and heavy metal ions such as Hg2+ inhibited enzyme activity. The activity of the endo-(1→3)-β-glucanase of krill strictly depended on free thiol groups in a enzyme molecule. The Michaelis constant value for laminaran was 0.063 mg/ml. Optimal determined temperature was 65°C and optimal pH 5.0. Because of this enzyme's strong interaction with concavalin A-Sepharose it is suggested that it might be a glycoprotein.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00999765
Permalink