Purification and Characterization of an Aspecific Glycoside Hydrolase from the Anaerobic Ruminal Fungus Neocallimastix frontalis.
A glycoside hydrolase characterized by beta-fucosidase (EC 3.2.1.38) and beta-glucosidase (EC 3.2.1.21) activities was purified from the culture medium of the anaerobic ruminal phycomycete Neocallimastix frontalis grown on 0.5% Avicel. The enzyme had a molecular mass of 120 kilodaltons and a pI of 3.85. Optimal activity against p-nitrophenyl-beta-d-fucoside and p-nitrophenyl-beta-D-glucoside occurred at pH 6.0 and 50 degrees C. The beta-fucosidase and beta-glucosidase activities were stable from pH 6.0 to pH 7.8 and up to 40 degrees C. They were both inhibited by gluconolactone, sodium dodecyl sulfate, p-chloromercuribenzoate, and Hg cation. The enzyme had K(m)s of 0.26 mg/ml for p-nitrophenyl-beta-d-fucoside and 0.08 mg/ml for p-nitrophenyl-beta-d-glucoside. The purified protein also had low beta-galactosidase activity.
Hebraud
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Laboratoire de Biologie Cellulaire Fongique, UMR Centre National de la Recherche Scientifique 106, Université de Lyon 1, Bâtiment 405-43, Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France.
Fevre
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