Cellobiose oxidase from Phanerochaete chrysosporium Stopped‐flow spectrophotometric analysis of pH‐dependent reduction

FEBS Letters

Eriksson, Karl-Erik L.¹  Samejima, Masahiro¹  Phillips, Robert S.¹ 

[1] Department of Biochemistry, University of Georgia, Athens, GA 30602-7229, USA

关键词: Cellobiose oxidase;    Cytochrome c;    Dichlorophenol-indophenol;    Stopped-flow spectrophotometry;    Phanerochaete chrysosporium;   

DOI  :  10.1016/0014-5793(92)80991-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cellobiose oxidase (CBO) from Phanetochaete chrysosporium can utilize dichlorphenol—indophenol (Cl₂Ind) and cytochrome c as effective electron acceptors for the oxidation of cellobiose. However, the pH dependencies of activity for these electron acceptors are significantly different. Both compounds act as effective electron acceptors at pH 4.2, whereas only dichlorophenol-indophenol is active at pH 5.9. To explain this discrepancy, the pH dependencies of the reduction rates of FAD and heme, respectively, in CBO by cellobiose have been investigated by stopped-flow spectrophotometry. Both FAD and heme are reduced with a high rate constant at pH 4.2. In contrast, at pH 5.9, only FAD reduction is fast, while the reduction of the heme is extremely slow. As a conclusion, the reduction of cytochrome c by CBO is dependent on heme, which functions at a lower pH range compared to reduction of FAD.

【 授权许可】

Unknown