Investigating the mechanisms of amylolysis of starch granules by solution-state NMR.
Biomacromolecules
; 16(5): 1614-21, 2015 May 11.
Article
en 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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Soluciones
/
Almidón
/
Alfa-Amilasas
Límite:
Humans
Idioma:
En
Revista:
Biomacromolecules
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2015
Tipo del documento:
Article
País de afiliación:
Reino Unido