Fine Substrate Specificities of Four Exo-Type Cellulases Produced by Aspergillus niger, Trichoderma reesei, and Irpex lacteus on (1->3),(1->4)- -D-Glucans and Xyloglucan
| Autor: | Takahisa Kanda, Yoshihiko Amano, Eiichi Hoshino, Kazutosi Nisizawa, Masahiro Shiroishi |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Glycoside Hydrolases
Irpex lacteus macromolecular substances Cellulase Cellobiose Biochemistry Substrate Specificity Fungal Proteins Structure-Activity Relationship chemistry.chemical_compound Polysaccharides Cellulose 1 4-beta-Cellobiosidase Glucans Molecular Biology Laminaribiose Chromatography High Pressure Liquid Trichoderma reesei Glucan Trichoderma chemistry.chemical_classification biology fungi Aspergillus niger food and beverages General Medicine beta-Galactosidase biology.organism_classification carbohydrates (lipids) Xyloglucan chemistry biology.protein Xylans Chromatography Thin Layer |
| Zdroj: | Journal of Biochemistry. 120:1123-1129 |
| ISSN: | 0021-924X |
| DOI: | 10.1093/oxfordjournals.jbchem.a021531 |
| Popis: | To investigate the fine substrate specificities of four highly purified exo-type cellulases (Exo-A from Aspergillus niger, CBHI and CBHII from Trichoderma reesei, and Ex-1 from Irpex lacteus), water-soluble substrates such as barley glucan, xyloglucan from tamarind (Tamarindus indica L.), and their oligosaccharides were employed. Four exo-type cellulases immediately hydrolyzed 3-O-beta-D-cellotriosylglucose to produce cellobiose and laminaribiose. In contrast, CBHII showed no hydrolytic activity towards 3(2)-O-beta-D-cello-biosylcellobiose, which was hydrolyzed to cellobiose by the other exo-type cellulases. These cellulases hydrolyzed the internal linkages of barley glucan and lichenan in an endo-type fashion to produce cellobiose and mix-linked oligosaccharides as main products. The DP-lowering activities of the four exo-type cellulases on barley glucan were in the order of Ex-1, CBHII, Exo-A, and CBHI. Based on gel permeation chromatography analysis of the hydrolysates, Ex-1 seemed to attack the internal cellobiosyl unit adjacent to beta-1,3-glucosidic linkages in barley glucan molecule more frequently than did the other cellulases. Xyloglucan was hydrolyzed only by CBHI and CBHII, and produced hepta-, octa-, and nona-saccharides. In addition, a xyloglucan tetradecasaccharide (XG14) was split only to heptasaccharide (XG7) by CBHI and CBHII. |
| Databáze: | OpenAIRE |
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