beta-maltose 4-alpha-glucanotransferase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: beta-D-glucose + a plant soluble heteroglycan = a plant soluble heteroglycan + maltose. [EC:2.4.1.25, GOC:pz]

Beta-maltose 4-alpha-glucanotransferase activity refers to the enzymatic activity that catalyzes the transfer of a maltose unit from a donor molecule, such as maltose or a larger oligosaccharide, to the non-reducing end of an acceptor molecule, typically an alpha-1,4-linked glucan chain. This process results in the formation of a new alpha-1,4-glucosidic linkage and the elongation of the acceptor molecule. The reaction is reversible, and the enzyme can also catalyze the reverse reaction, which involves the hydrolysis of alpha-1,4-glucosidic linkages.

The primary function of beta-maltose 4-alpha-glucanotransferase is to modify the structure of starch molecules. It can introduce branch points in amylose chains by transferring maltose units to existing alpha-1,4-linked glucan chains, forming alpha-1,6-glucosidic linkages. These branch points play a critical role in determining the physical and chemical properties of starch, such as its viscosity, gelatinization temperature, and digestibility.

The enzyme is also involved in the biosynthesis of amylopectin, a branched form of starch. It transfers maltose units from maltose or oligosaccharides to growing amylopectin chains, contributing to the formation of its characteristic branched structure.

Moreover, beta-maltose 4-alpha-glucanotransferase can be involved in the degradation of starch molecules. By hydrolyzing alpha-1,4-glucosidic linkages, it can break down starch into smaller oligosaccharides, which can be further degraded by other enzymes.

The activity of beta-maltose 4-alpha-glucanotransferase is regulated by various factors, including pH, temperature, and the presence of specific ions or cofactors. The enzyme is found in a wide range of organisms, including bacteria, fungi, plants, and animals, and plays a critical role in the metabolism of starch and other carbohydrates.'
"

Proteins (1)

Compounds (11)