Synergistic interactions among beta-laminarinase, beta-1,4-glucanase, and beta-glucosidase from the hyperthermophilic archaeon Pyrococcus furiosus during hydrolysis of beta-1,4-, beta-1,3-, and mixed-linked polysaccharides

The synergistic interaction among three p-specific glycosidases from the hy perthermophilic archaeon Pyrococcus furiosus, namely two endoglucanases (Eg lA and LamA) and an exo-acting p-glucosidase (Bgl), on barley-glucan and la minarin, was examined. In addition to following glucose release and the gen eration of reducing sugar ends, the distribution and amounts of oligomeric products from beta-1,3- and beta-1,4-linked substrates were determined as a function of extent of hydrolysis at 98 degrees C. Positive interactions we re noted between endo/exo glucanase combinations, leading to enhanced and r apid degradation of the larger complex carbohydrates to oligosaccharides. T he EgIA/LamA endo-acting combination was also synergistic in degrading barl ey-glucan. However, hydrolysis was most efficient when a blend of all three hydrolases was used, possibly due to the relief of product inhibition by t he exoglyosidase. Furthermore, by monitoring the distribution of oligosacch arides present during hydrolysis, patterns of enzymatic attack could be fol lowed in addition to determining the specific contributions of each hydrola se to the overall process. (C) 1999 John Wiley & Sons, Inc.