Alternansucrase
In enzymology, an alternansucrase (EC2.4.1.140) is an enzyme that catalyzes a chemical reaction that transfers an alpha-D-glucosyl residue from sucrose alternately to the 6- and 3-positions of the non-reducing terminal residue of an alpha-D-glucan, thereby creating a glucan with alternating alpha-1,6- and alpha-1,3-bonds. The name "alternan" was coined in 1982 (Cote & Robyt) for the glucan based on its alternating linkage structure.