Investigating the mechanisms of amylolysis of starch granules by solution-state NMR.
Biomacromolecules
; 16(5): 1614-21, 2015 May 11.
Article
in En
| MEDLINE
| ID: mdl-25815624
ABSTRACT
Starch is a prominent component of the human diet and is hydrolyzed by α-amylase post-ingestion. Probing the mechanism of this process has proven challenging, due to the intrinsic heterogeneity of individual starch granules. By means of solution-state NMR, we demonstrate that flexible polysaccharide chains protruding from the solvent-exposed surfaces of waxy rice starch granules are highly mobile and that during hydrothermal treatment, when the granules swell, the number of flexible residues on the exposed surfaces increases by a factor of 15. Moreover, we show that these flexible chains are the primary substrates for α-amylase, being cleaved in the initial stages of hydrolysis. These findings allow us to conclude that the quantity of flexible α-glucan chains protruding from the granule surface will greatly influence the rate of energy acquisition from digestion of starch.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Solutions
/
Starch
/
Alpha-Amylases
Limits:
Humans
Language:
En
Journal:
Biomacromolecules
Journal subject:
BIOLOGIA MOLECULAR
Year:
2015
Document type:
Article
Affiliation country:
United kingdom