Location: Renewable Product Technology ResearchTitle: Production of isomelezitose from sucrose by engineered glucansucrases
Submitted to: Amylase
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/8/2017
Publication Date: 12/29/2017
Publication URL: https://handle.nal.usda.gov/10113/5935354
Citation: Cote, G.L., Dunlap, C.A., Vermillion, K.E., & Skory, C.D. 2017. Production of isomelezitose from sucrose by engineered glucansucrases. Amylase. 1(1):82-93. doi: 10.1515/amylase-2017-0008.
Interpretive Summary: Isomelezitose is an unusual sugar with anticipated applications in pharmaceutical, agricultural, and food industries. This natural sugar was previously found in trace amounts in honey, but efforts to commercialize it were hampered by the high cost of production. In this work, we have created modified bacterial enzymes that are capable of producing high yields of isomelezitose from the common sugar sucrose. This significant discovery now allows researchers to study potential applications of the novel sugar, which will likely include improving the long-term storage stability of foods, drugs, vaccines, and agricultural bio-control agents.
Technical Abstract: Certain lactic acid bacteria produce glycosyltransferases known as glucansucrases, which synthesize a-D-glucans via glucosyl transfer from sucrose. We recently reported on the formation of the unusual trisaccharide isomelezitose in low yields by a variety of glucansucrases. Isomelezitose is a rare non-reducing trisaccharide, with the structure a-D-glucopyranosyl-(1'6)-ß-D-fructofuranosyl-(2'1)-a-D-glucopyranoside. In this work, we describe the synthesis of isomelezitose in high yields by variants of glucansucrases engineered to contain a single point mutation at a key leucine residue involved in acceptor substrate binding. Some variants produce isomelezitose in yields up to 57%. This method is amenable to large-scale production of isomelezitose for food, industrial and biomedical applications.