4-alpha-glucanotransferase activity

Definition

Target type: molecularfunction

Catalysis of the transfer of a segment of a (1->4)-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or (1->4)-alpha-D-glucan. [EC:2.4.1.25]

4-alpha-glucanotransferase activity is a molecular function that catalyzes the transfer of a glucosyl moiety from one alpha-1,4-linked glucan to another alpha-1,4-linked glucan. Specifically, it involves the transfer of a glucosyl unit from a donor molecule, such as amylose or amylopectin, to an acceptor molecule, which can be another starch molecule or a different oligosaccharide. This transfer results in the formation of a new alpha-1,4-glycosidic linkage, extending the acceptor molecule.

The process is crucial for the biosynthesis and modification of starch and glycogen, which are essential energy storage molecules in plants and animals, respectively. 4-alpha-glucanotransferase activity plays a vital role in determining the structure and properties of these polysaccharides by facilitating branching and debranching reactions.

The enzyme responsible for this activity is known as 4-alpha-glucanotransferase or glucan branching enzyme. These enzymes are found in various organisms, including plants, animals, and microorganisms. They exhibit diverse substrate specificities and branching patterns, which contribute to the diversity of starch and glycogen structures observed in nature.

The regulation of 4-alpha-glucanotransferase activity is important for maintaining appropriate levels of starch and glycogen synthesis and degradation in response to metabolic needs. This regulation can involve factors such as substrate availability, enzyme concentration, and post-translational modifications.'
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Proteins (2)

Compounds (11)