Biomaterial Database

Model for carbohydrase action. Aspergillus oryzae alpha-amylase degradation of maltotriose. 1978

J D Allen, and J A Thoma

Aspergillus oryzae alpha-amylase catalyzes degradation of oligosaccharides by a variety of pathways. We present here a quantitative study of the degradation of maltotriose by this amylase. Our results lead to a scheme involving multiple transglycosylation reactions and shifted binding due to simultaneous binding of two substrate molecules. The scheme is able to account for the diverse body of information collected for the enzyme. The effect of substrate concentration on the products of maltotriose degradation is correctly predicted over a 10(4)-fold concentration range, and the time course of maltotriose degradation is closely approximated by this scheme. The initial velocity data, which show deviation from Michaelis-Menton kinetics, are also consistent with the formulated scheme. The scheme is proposed as a general model of carbohydrase action.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008320	Maltose	A dextrodisaccharide from malt and starch. It is used as a sweetening agent and fermentable intermediate in brewing. (Grant & Hackh's Chemical Dictionary, 5th ed)
D008956	Models, Chemical	Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Chemical Models,Chemical Model,Model, Chemical
D009844	Oligosaccharides	Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.	Oligosaccharide
D000516	alpha-Amylases	Enzymes that catalyze the endohydrolysis of 1,4-alpha-glycosidic linkages in STARCH; GLYCOGEN; and related POLYSACCHARIDES and OLIGOSACCHARIDES containing 3 or more 1,4-alpha-linked D-glucose units.	Taka-Amylase A,alpha-Amylase,Alpha-Amylase Bayer,Maxilase,Mégamylase,alpha-1,4-D-Glucanglucanohydrolase,Alpha Amylase Bayer,AlphaAmylase Bayer,Taka Amylase A,TakaAmylase A,alpha 1,4 D Glucanglucanohydrolase,alpha Amylase,alpha Amylases
D000681	Amylases	A group of amylolytic enzymes that cleave starch, glycogen, and related alpha-1,4-glucans. (Stedman, 25th ed) EC 3.2.1.-.	Diastase,Amylase
D001236	Aspergillus oryzae	An imperfect fungus present on most agricultural seeds and often responsible for the spoilage of seeds in bulk storage. It is also used in the production of fermented food or drink, especially in Japan.	Eurotium oryzae
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D014312	Trisaccharides	Oligosaccharides containing three monosaccharide units linked by glycosidic bonds.	Trisaccharide