4-alpha-glucanotransferase
In enzymology, a 4-alpha-glucanotransferase is an enzyme that catalyzes a chemical reaction that transfers a segment of a 1,4-alpha-D-glucan to a new position in an acceptor carbohydrate, which may be glucose or a 1,4-alpha-D-glucan.
This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase. Other names in common use include disproportionating enzyme, dextrin glycosyltransferase, D-enzyme, debranching enzyme maltodextrin glycosyltransferase, amylomaltase, and dextrin transglycosylase. This enzyme participates in starch and sucrose metabolism in plants. Studies of the enzyme from potato led to the discovery of cycloamylose.