ARS | Publication request: Alternansucrase acceptor products

Submitted to: Biocatalysis and Biotransformation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 19, 2007
Publication Date: February 28, 2008
Citation: Cote, G.L., Sheng, S., Dunlap, C.A. 2008. Alternansucrase acceptor products. Biocatalysis and Biotransformation. 26(1-2):161-168.

Interpretive Summary: Fundamental information on the structures of novel sugar-based food ingredients is required in order to understand and predict their nutritional role and acitivity. In this paper, we isolate a series of carbohydrate components from a novel sugar-derived food ingredient and determine their chemical structures. These results tell us important facts about how the enzyme that makes these products works. They also give us more information about the new ingredient, which may allow us to better understand how it is digested in the body. These results will be of interest to food ingredient manufacturers, food formulators, and researchers.

Technical Abstract: The regioselectivity of alternansucrase (EC 2.4.1.140) differs from dextransucrase (EC 2.4.1.5) in ways that can be useful for the synthesis of novel oligosaccharide structures. For example, it has been recently shown that the major oligosaccharides produced when maltose is the acceptor include one trisaccharide structure, two tetrasaccharides, one pentasaccharide, two hexasaccharides, and one heptasaccharide, containing no adjacent alpha-(1-3) linkages and no more than two consecutive alpha-(1-6) linkages. This may shed some light on how the enzyme works to produce the alternating structure. Another characteristic of alternansucrase that distinguishes it from dextransucrase is its greater ability to use leucrose as an acceptor. Leucrose, produced by glucosyl transfer to fructose released from the initial sucrose substrate, represents a very poor substrate for Leuconostoc mesenteroides NRRL B-512F dextransucrase. Alternansucrase, however, continues to transfer glucosyl units to leucrose, resulting in some unusual glucosyl-fructose oligosaccharides.