Resolution, purification and some properties of the multiple forms of cellobiose quinone dehydrogenase from the white-rot fungus Sporotrichum pulverulentum

Abstract

Four forms of cellobiose quinone dehydrogenase have been purified from the white-rot fungus Sporotrichum pulverulentum. The Mr of the enzyme has been estimated by sedimentation equilibrium to be 57800 and by SDS/polyacrylamide-gel to be 60000. These enzymes are clearly monomers. Cellobiose quinone dehydrogenases contain FAD and variable amounts of a green chromophore which we suggest is 6-hydroxy-FAD. The superoxide anion and H2O2 are the products of its reaction with oxygen. All of the isoenzymes from any one preparation display similar kinetic parameters. However, these vary between preparations. The only apparent difference between the four separable isoenzymes is their neutral-sugar content.