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Title: Structural characterization of carbohydrate attached to the glycoprotein cellulase enzymes of Trichoderma reesei QM 9414

Thesis/Dissertation ·
OSTI ID:6195066

Cellobiohydrolases I(D) and II were purified by ion exchange chromatography from an extracellular culture filtrate of Tricoderma reesei QM 9414. Neutral sugar composition of each was determined by gas-liquid chromatographic analysis of the peracetylated alditol and aldononitrile acetate derivatives of sugars released by either reductive US -elimination or acid hydrolysis. The alkaline borohydride-released carbohydrate was analyzed by high-pressure liquid chromatography (HPLC). The HPLC data demonstrated that each molecule of cellobiohydrolase I(D) contained 5.9% carbohydrate and that cellobiohydrolase II contained 18.9% carbohydrate. The purified oligosaccharides were shown by methylation analysis to contain (1-2) and (1-6) glycosidic linkages and the position of the 6-substituted residues was confirmed by acetolysis. The sequence and anomeric nature of the sugar residues in each oligosaccharide was determined by sequential glycosidase digestion, and all the residues were found to be -linked. Proton decoupled TC-NMR analysis suggested that for cellobiohydrolase I(D), each oligosaccharide was attached to a threonyl residue on the polypeptide and for cellobiohydrolase II, each oligosaccharide was attached to threonyl and seryl residues on the polypeptides. Coupled TC-NMR and H-NMR data to define the structures of the oligosaccharides attached to the enzyme were determined and are reported. Thus, work with the cellobiohydrolases and the endoglucanases indicated that the predominant cellulase enzymes secreted by T. reesei QM 9414 are each glycosylated with similar oligosaccharides.

Research Organization:
Florida Univ., Gainesville (USA)
OSTI ID:
6195066
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English