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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #365082
Title: Contribution of the individual small intestinal alpha-glucosidases to digestion of unusual alpha-linked glycemic disaccharides

Author
item LEE, BYUNG-HOO - Gachon University
item ROSE, DAVID - University Of Waterloo
item LIN, AMY - Purdue University
item QUEZADA-CALVILLO, ROBERTO - Autonomous University Of San Luis Potosi
item NICHOLS, BUFORD - Children'S Nutrition Research Center (CNRC)
item HAMAKER, BRUCE - Purdue University

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2016
Publication Date: 8/2/2016
Citation: Lee, B., Rose, D.R., Lin, A.H., Quezada-Calvillo, R., Nichols, B.L., Hamaker, B.R. 2016. Contribution of the individual small intestinal alpha-glucosidases to digestion of unusual alpha-linked glycemic disaccharides. Journal of Agricultural and Food Chemistry. 64(33):6487-6494. https://doi.org/10.1021/acs.jafc.6b01816.
DOI: https://doi.org/10.1021/acs.jafc.6b01816

Interpretive Summary: Low glycemic index foods are associated with reduced risk of common chronic health diseases and has led to search for carbohydrates with slow digestion rate. Digestion properties of a range of disaccharides of different linkage and monosaccharide compositions were investigated with the aim of finding new ways to control the rate of glucogenesis by added dietary disaccharides. Isomers of disaccharides with identical chemical formulas but distinct structures were tested. Hydrolytic properties of the maltose and sucrose isomers were determined using rat intestinal and individual recombinant alpha-glucosidases. The individual alpha-glucosidases all had slower activities from all alpha-linked isomers of disaccharides. Maltase (N-terminal MGAM) showed a greater ability to digest alpha-1,2 and alpha-1,3 isomers, as well as alpha-1,4, making it the most versatile in alpha-hydrolytic activity. These findings apply to the development of new glycemic oligosaccharides based on unusual alpha-linkages for extended glycemic response.

Technical Abstract: The mammalian mucosal a-glucosidase complexes, maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI), have two catalytic subunits (N- and C-termini). Concurrent with the desire to modulate glycemic response, there has been a focus on di-/oligosaccharides with unusual alpha-linkages that are digested to glucose slowly by these enzymes. Here, we look at disaccharides with various possible alpha-linkages and their hydrolysis. Hydrolytic properties of the maltose and sucrose isomers were determined using rat intestinal and individual recombinant alpha-glucosidases. The individual alpha-glucosidases had moderate to low hydrolytic activities on all alpha-linked disaccharides, except trehalose. Maltase (N-terminal MGAM) showed a higher ability to digest alpha-1,2 and alpha-1,3 disaccharides, as well as alpha-1,4, making it the most versatile in alpha-hydrolytic activity. These findings apply to the development of new glycemic oligosaccharides based on unusual alpha-linkages for extended glycemic response. It also emphasizes that mammalian mucosal alpha-glucosidases must be used in in vitro assessment of digestion of such carbohydrates.