Evidence of native starch degradation with human small intestinal maltase-glucoamylase (recombinant)

FEBS Lett. 2007 May 29;581(13):2381-8. doi: 10.1016/j.febslet.2007.04.035. Epub 2007 Apr 24.


Action of human small intestinal brush border carbohydrate digesting enzymes is thought to involve only final hydrolysis reactions of oligosaccharides to monosaccharides. In vitro starch digestibility assays use fungal amyloglucosidase to provide this function. In this study, recombinant N-terminal subunit enzyme of human small intestinal maltase-glucoamylase (rhMGAM-N) was used to explore digestion of native starches from different botanical sources. The susceptibilities to enzyme hydrolysis varied among the starches. The rate and extent of hydrolysis of amylomaize-5 and amylomaize-7 into glucose were greater than for other starches. Such was not observed with fungal amyloglucosidase or pancreatic alpha-amylase. The degradation of native starch granules showed a surface furrowed pattern in random, radial, or tree-like arrangements that differed substantially from the erosion patterns of amyloglucosidase or alpha-amylase. The evidence of raw starch granule degradation with rhMGAM-N indicates that pancreatic alpha-amylase hydrolysis is not a requirement for native starch digestion in the human small intestine.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Digestion
  • Glucan 1,4-alpha-Glucosidase / metabolism
  • Humans
  • Hydrolysis
  • Intestine, Small / enzymology*
  • Kinetics
  • Manihot
  • Pancreas / enzymology
  • Recombinant Proteins / metabolism
  • Rhizopus / enzymology
  • Starch / metabolism*
  • Zea mays
  • alpha-Amylases / metabolism
  • alpha-Glucosidases / metabolism*


  • Recombinant Proteins
  • Starch
  • alpha-Amylases
  • alpha-Glucosidases
  • Glucan 1,4-alpha-Glucosidase