Mammalian mucosal alpha-glucosidases coordinate with alpha-amylase in the initial starch hydrolysis stage to have a role in Starch Digestion beyond Glucogenesis

Dhital, Sushil, Lin, Amy Hui-Mei, Hamaker, Bruce R., Gidley, Michael J. and Muniandy, Anbuhkani (2013) Mammalian mucosal alpha-glucosidases coordinate with alpha-amylase in the initial starch hydrolysis stage to have a role in Starch Digestion beyond Glucogenesis. PLoS One, 8 4: e62546.1-e62546.13. doi:10.1371/journal.pone.0062546


Author Dhital, Sushil
Lin, Amy Hui-Mei
Hamaker, Bruce R.
Gidley, Michael J.
Muniandy, Anbuhkani
Title Mammalian mucosal alpha-glucosidases coordinate with alpha-amylase in the initial starch hydrolysis stage to have a role in Starch Digestion beyond Glucogenesis
Formatted title
Mammalian Mucosal α-Glucosidases Coordinate with α-Amylase in the Initial Starch Hydrolysis Stage to Have a Role in Starch Digestion beyond Glucogenesis
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2013-04
Year available 2013
Sub-type Article (original research)
DOI 10.1371/journal.pone.0062546
Open Access Status DOI
Volume 8
Issue 4
Start page e62546.1
End page e62546.13
Total pages 13
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Collection year 2014
Language eng
Formatted abstract
Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing predominantly α-amylase, and intestinal extract containing a combination of α-amylase and mucosal α-glucosidase activities, were applied to three granular maize starches with different amylose contents in an in vitro system. Relative glucogenesis, released maltooligosaccharide amounts, and structural changes of degraded residues were examined. Pancreatic extract-treated starches showed a hydrolysis limit over the 12 h incubation period with residues having a higher gelatinization temperature than the native starch. α-Amylase combined with the mucosal α-glucosidases in the intestinal extract showed higher glucogenesis as expected, but also higher maltooligosaccharide amounts indicating an overall greater degree of granular starch breakdown. Starch residues after intestinal extract digestion showed more starch fragmentation, higher gelatinization temperature, higher crystallinity (without any change in polymorph), and an increase of intermediate-sized or small-sized fractions of starch molecules, but did not show preferential hydrolysis of either amylose or amylopectin. Direct digestion of granular starch by mammalian recombinant mucosal α-glucosidases was observed which shows that these enzymes may work either independently or together with α-amylase to digest starch. Thus, mucosal α-glucosidases can have a synergistic effect with α-amylase on granular starch digestion, consistent with a role in overall starch digestion beyond their primary glucogenesis function.
Keyword Hereditary Disaccharide Intolerance
Human Intestinal Disaccharidases
Maltase Glucoamylase
Sucrase-Isomaltase
Granules
Glucose
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
Centre for Nutrition and Food Sciences Publications
 
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