Nojirimycin and d-glucono-1,5-lactone as inhibitors of carbohydrases

Induction of lignocellulose-degrading enzymes in Neurospora crassa by cellodextrins

“…Early studies used the β-glucosidase inhibitor nojirimycin to show that cellobiose induces cellulases in the lignocellulose-degrading filamentous fungus, T. reesei (17,18). However, this induction was not as robust as with other soluble inducers including lactose (25) or sophorose (12).…”

“…A complicating factor in understanding the regulation of cellulase gene expression is inhibition of cellulase production due to carbon catabolite repression (CCR) (4) by the end product of cellulose hydrolysis, glucose. Previous studies in T. reesei showed that nojirimycin inhibition of β-glucosidase, the enzyme that converts cellobiose into glucose in the final step of cellulose hydrolysis, allows a moderate induction of cellulases by cellobiose (17)(18)(19).…”

.ALPHA.-Glucosidase Inhibitors from Garcinia brevipedicellata (Clusiaceae)

“…They delay the absorption of carbohydrates from the small intestine and thus have a lowering effect on postprandial blood glucose and insulin levels. 14) Nojirimycin 15,16) and Acarbose 17) are known to be a-glucosidase inhibitors derived from microorganisms. In the search for alternative powerful a-glucosidase inhibitors, we speculated that analysis of the secondary metabolites synthesized by plants would be a promising line of inquiry.…”

Partial Characterization of Cx Cellulase and Cellobiase from Ripening Tomato Fruits

“…D-Glucono-1 , 5-lactone is a powerful competitive inhibitor of cellobiase but a very poor inhibitor of exoglucanases and endoglucanases (24,28,29). Preparatory to gluconolactone inhibition studies with the tomato enzyme, cellobiose substrate saturation experiments were conducted.…”

“…Both enzymes have broad substrate specificities and substrates in common. However, they differ markedly in Km for different substrates (20), mode of attack (15,20), and susceptibility to inhibitors (28,29). Thus, several means exist for distinguishing between the activities of exoglucanases and cellobiases in spite of the facts that their substrate specificities overlap and that the product of each reaction is glucose.…”