Cellobiose-oxidizing enzymes from the lignocellulose-degrading basidiomycetePhanerochaete chrysosporium:interaction with microcrystalline cellulose
✍ Scribed by V. Renganathan; S. N. Usha; Flordeliz Lindenburg
- Publisher
- Springer
- Year
- 1990
- Tongue
- English
- Weight
- 457 KB
- Volume
- 32
- Category
- Article
- ISSN
- 1432-0614
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✦ Synopsis
Cellulose-degrading cultures of the white-rot fungus Phanerochaete chrysosporium produce two extracellular cellobiose-oxidizing enzymes, cellobiose oxidase and cellobiose:quinone oxidoreductase. These two enzymes bind strongly to microcrystalline cellulose (MCC) in the pH range 4-7; above neutral pH their affinity for MCC decreases. Cellulose-bound enzymes could not be eluted with phosphate buffer (20 mM, pH 6) containing polyols (10%), KC1 (1 M), urea (1 M) or 1% ionic or non-ionic detergent. TRIS or borate buffer at pH 9 eluted 30%-35% of the cellobiose-oxidizing enzyme activity. The celluloseimmobilized enzymes oxidized cellobiose actively, suggesting that the catalytic sites are not involved in cellulose binding. These results suggest that the cellobiose-oxidizing enzymes of P. chrysosporium may be organized into two domains: a cellulose-binding domain and a catalytic domain.