Contribution of the Individual Small Intestinal α-Glucosidases to Digestion of Unusual α-Linked Glycemic Disaccharides

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• 作者：Byung-Hoo Lee ; David R. Rose ; Amy Hui-Mei Lin ; Roberto Quezada-Calvillo ; Buford L. Nichols ; Bruce R. Hamaker
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：August 24, 2016
• 年：2016
• 卷：64
• 期：33
• 页码：6487-6494
• 全文大小：378K
• 年卷期：0
• ISSN：1520-5118

文摘

The mammalian mucosal α-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 α-linkages that are digested to glucose slowly by these enzymes. Here, we look at disaccharides with various possible α-linkages and their hydrolysis. Hydrolytic properties of the maltose and sucrose isomers were determined using rat intestinal and individual recombinant α-glucosidases. The individual α-glucosidases had moderate to low hydrolytic activities on all α-linked disaccharides, except trehalose. Maltase (N-terminal MGAM) showed a higher ability to digest α-1,2 and α-1,3 disaccharides, as well as α-1,4, making it the most versatile in α-hydrolytic activity. These findings apply to the development of new glycemic oligosaccharides based on unusual α-linkages for extended glycemic response. It also emphasizes that mammalian mucosal α-glucosidases must be used in in vitro assessment of digestion of such carbohydrates.