title: Multimolecular substrate reactions catalyzed by caabohydrases. Aspergillus oryzae alpha-amylase degradation of maltooligosaccharides.
abstract: Aspergillus oryzae alpha-amylase degrades maltooligosaccharides by other pathways besides simple glycosidic bond scission. The utilization of the alternate pathways increases with the concentration of substrate implicating a multimolecular substrate mechanism. Reducing-end labeled and uniformly labeled maltooligosaccharides were used to elucidate these alternate degradation mechanisms. Condensation followed by hydrolysis is not a significant pathway. Transglycosylation is concluded to occur, but no single transglycosylation mechanism can account for all of the experimental data for maltotriose degradation. Rather, a combination of transglycosylations must be invoked.
mesh_terms: D000681:Amylases / Q000378:metabolism*; D001236:Aspergillus oryzae / Q000201:enzymology; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D008320:Maltose / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D013379:Substrate Specificity; D014312:Trisaccharides / Q000378:metabolism; D000516:alpha-Amylases / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; D014312:Trisaccharides; D008320:Maltose; D000681:Amylases; D000516:alpha-Amylases