Cellobiose dehydrogenase from Schizophyllum commune: purification and study of some catalytic, inactivation, and cellulose-binding properties.
Cellobiose dehydrogenase (CDH) of Schizophyllum commune was purified to homogeneity. It is a glycoprotein with a molecular mass of 102, 000. Cellulosic substrates can serve as substrates for CDH. Cytochrome c, dichlorophenol-indophenol, ferricyanide, and oxygen can be reduced by the enzyme. CDH is stable in the pH range of 4-11 and up to 35 degrees C. The enzyme keeps active at high concentrations of H2O2. In the presence of cellobiose and Fe3+, incubation of CDH resulted in its inactivation and the degree of the inactivation was dependent mainly on the amount of CDH and cellobiose present. CDH has a distinct and specific affinity to cellulose and showed the strongest binding to acid-treated cellulose. The adsorption isotherm data fitted the Langmuir-type equation. The uv-visible spectra of the oxidized and reduced states of CDH showed a typical cytochrome b-type pattern. Addition of dithionite eliminated the adsorption between 440 and 500 nm, which indicates the presence of a flavin group in CDH.
Fang
J
J
The State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People's Republic of China.
Liu
W
W
Gao
P J
PJ
D002237:Carbohydrate Dehydrogenases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002384:Catalysis; D002412:Cations / Q000494:pharmacology; D002482:Cellulose / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004578:Electron Spin Resonance Spectroscopy; D004795:Enzyme Stability; D006023:Glycoproteins / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D011485:Protein Binding; D012567:Schizophyllum / Q000201:enzymology*; D013379:Substrate Specificity
D002412:Cations; D006023:Glycoproteins; D002482:Cellulose; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase