PURIFICATION AND CHARACTERIZATION OF GLUCOSE-OXIDASE OF BOTRYTIS-CINEREA

The H2O2-producing enzyme glucose oxidase of the phytopathogenic fungu s Botrytis cinerea was purified to homogeneity by anion-exchange chrom atography and chromatofocusing. The enzyme has its pH optimum at 7.5 a nd an isoelectric point of 4.2. The enzyme appears to be a tetrameric protein with a native molecular weight of about 160 kDa. Like the gluc ose oxidase of Phanerochaete chrysosporium, the glucose oxidase of B. cinerea is not glycosylated. Analysis of substrate specificity confirm ed that beta-D-glucose is the specific substrate of the enzyme. The ex pression of the glucose oxidase of B. cinerea is induced by low glucos e concentration in the culture medium. In this respect, the glucose ox idase of B. cinerea is also similar to the glucose oxidase of P. chrys osporium and differs from the glucose oxidases of Aspergillus and Peni cillium, which require high glucose concentrations for expression. (C) 1998 Academic Press.