Isolation, Purification, and Investigation of Some Properties of Glucose Oxidase of the Wood-Degrading Fungus Lentinus (Panus) tigrinus Strain VKM F-3616D

摘要

The activity and some properties of glucose oxidase (EC 1.1.3.4) of the wood-degrading fungus Lentinus (Panus) tigrinus VKM F-3616D were studied. The results showed that 12 days of dynamic liquid-phase cultivation increased the activity and the biosynthetic levels of the enzyme with maximal activity at day 6. After 6 days, a decrease in the glucose oxidase activity was observed. The enzyme isolated via ion exchange chromatography had an optimal pH of 4.0 and a temperature optimum of 50 degrees C. Spectrophotometry, fluorescence analysis, and IR Fourier spectroscopy showed that the enzyme was a flavoprotein and that its prosthetic group contains flavin adenine dinucleotide. The relative kinetic parameters of the enzyme were determined: the Michaelis constant (K-m) was 4.1 x 10(-3) M, and the maximal rate of the enzymatic reaction (V-max) was 0.36 IU. Results of electrophoresis in native and denaturing conditions were consistent with an enzyme structure having two equal subunits with a total molecular mass of approximately 160 kDa.