An endo-(1 leads to 3)-beta-D-glucanase from Mucor hiemalis

An endo-(1 leads to 3)-beta-D-glucanase (EC 3.2.1.6), isolated from the culture filtrate of the fungus Mucor hiemalis, was purified by ammonium sulfate fractionation, gel filtration, and column chromatography on O-(carboxymethyl)cellulose. The optimum pH, optimum temperature, and Km value of the enzyme were pH 5.0, 50 degrees, and 0.048%, respectively. The enzyme was strongly inactivated by Pb2+, Cu2+, and Hg2+ ions and also inhibited by Zn2+ and Fe3+ ions. The enzyme was specific for laminaran and the action pattern of the enzyme was of the endo-type. The molecular weight of the enzyme, as determined by gel filtration, was 30,000.