Effects of thermal denaturation on the solid-state structure and molecular mobility of glycinin.

Autor: Huson MG; CSIRO Food Futures Flagship, North Ryde, NSW 2113, Australia. mickey.huson@csiro.au, Strounina EV, Kealley CS, Rout MK, Church JS, Appelqvist IA, Gidley MJ, Gilbert EP
Jazyk: angličtina
Zdroj: Biomacromolecules [Biomacromolecules] 2011 Jun 13; Vol. 12 (6), pp. 2092-102. Date of Electronic Publication: 2011 May 06.
DOI: 10.1021/bm200080h
Abstrakt: The effects of moisture and thermal denaturation on the solid-state structure and molecular mobility of soy glycinin powder were investigated using multiple techniques that probe over a range of length and time scales. In native glycinin, increased moisture resulted in a decrease in both the glass transition temperature and the denaturation temperature. The sensitivity of the glass transition temperature to moisture is shown to follow the Gordon-Taylor equation, while the sensitivity of the denaturation temperature to moisture is modeled using Flory's melting point depression theory. While denaturation resulted in a loss of long-range order, the principal conformational structures as detected by infrared are maintained. The temperature range over which the glass to rubber transition occurred was extended on the high temperature side, leading to an increase in the midpoint glass transition temperature and suggesting that the amorphous regions of the newly disordered protein are less mobile. (13)C NMR results supported this hypothesis.
Databáze: MEDLINE