Maltase Has Most Versatile alpha-Hydrolytic Activity Among the Mucosal alpha-Glucosidases of the Small Intestine

Abstract

Complete digestion of the glycemic carbohydrates to glucose takes place through the combined action of the 4 mucosal alpha-glucosidases (maltaseglucoamylase and sucrase-isomaltase) in the small intestine. Maltase digests alpha-1,2-and alpha-1,3-disaccharides better than the other alpha-glucosidases, and has, as well, the capability to effectively hydrolyze alpha-1,4 and alpha-1,6 linkages that form the major backbone of a starch molecule. This broad hydrolytic activity on alpha-linkages makes it an enzyme that has the most versatile alpha-hydrolytic activity among the 4 mucosal alpha-glucosidases. The slowly digestible properties of the unusual linkages from this research suggest the development of new glycemic oligosaccharides which will be hydrolyzed slowly, compared to alpha-1,4 linkages, for modulating the postprandial glycemic response. In addition, using mammalian mucosal alpha-glucosidases is a better fit to characterize carbohydrate digestion properties, compared to fungal amyloglucosidase which is currently applied in in vitro assays.