Isolation of a β-glucosidase binding and activating polysaccharide from cell walls ofTrichoderma reesei

✍ Scribed by Robert Messner; Karl Hagspiel; Christian P. Kubicek

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 663 KB
• Volume: 154
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00423325

✦ Synopsis

The extracellular fi-glucosidase from the filamentous fungus Trichoderma reesei QM 9414 is mainly bound to the cell wall of the fungus and only partially released into the medium. Isolation of the cell walls and its hydrolysis by enzymatic treatment with Aspergillus niger cellulase released fi-glucosidase, which appeared tightly associated with a cell wall polysaccharide. This polysaccharide was purified by gel filtration and ion exchange chromatography and was shown to consist of mannose, galactose, glucose, galacturonic acid and glucuronic acid. It was devoid of protein and phosphate. It reassociated both with extracellular fi-glucosidase as well as fi-glucosidase released from the fungus' cell wall. Addition of the polysaccharide to the fi-glucosidase in vitro increased the enzyme's activity against 4-nitrophenyl-/?glucoside twofold. These findings suggest, that the isolated polysaccharide functions as an "anchor glycan" for the fi-glucosidase in Trichoderma reesei.