ISOLATION AND CHARACTERIZATION OF 2 ENDO-BETA-GLUCANASES FROM SOLID-STATE CULTURES OF THE AEROBIC FUNGUS PENICILLIUM-CAPSULATUM

Two endo-beta-glucanases from solid-state cultures of Penicillium capsulatum, have been purified to apparent homogeneity as judged by electrophoresis and isoelectric focusing. Each enzyme is a single subunit glycoprotein, containing 55-60 moles of carbohydrate per mole of glycoprotein. Enzyme A has an M(r) value of 38 kDa and a pI of 4.12, while form B has an M(r) of 36 kDa and a pI of 3.92. Bothenzymes are similar with respect to pH and temperature optima (pH 5 and 65-degrees-C, respectively) and under these conditions have half-lives of 3.5 h. They are also similar with respect to substrate specificity and kinetic parameters. Comparison of the rates of reduction in viscosity of solutions of beta-glucan with the rates of release of reducing equivalents therefrom showed each enzyme to be endoacting. This was confirmed by fractionation of the reaction products. On the basis of the above, each enzyme has been classified as an endo-beta-1,4-glucan 4 glucanohydrolase (EC 3.2.1.4).