Abstract:
:We have used the elastic neutron scattering technique to investigate the dynamics of the two main saccharidic components of starch: amylose and amylopectin. The measurements were carried out in the temperature range of 20 to 320 K and at different hydration levels from the dry state up to 0.47 g saccharide/g D(2)O. In the dry samples, the atomic dynamics is harmonic up to approximately 300 K. In the hydrated samples a "glass-like" transition leading to an anharmonic dynamics is observed. The onset of the anharmonicity occurs at temperatures that increase from approximately 180 K to 260 K upon decreasing hydration from 0.5 to 0.1 g saccharide/g D(2)O. This behavior is qualitatively similar to that observed in hydrated globular proteins, but quantitative differences are present. Assuming a simple asymmetric double-well potential model, the temperature and hydration dependence of the transition have been described in terms of few physical parameters.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Di Bari M,Cavatorta F,Deriu A,Albanese Gdoi
10.1016/S0006-3495(01)75776-1subject
Has Abstractpub_date
2001-08-01 00:00:00pages
1190-4issue
2eissn
0006-3495issn
1542-0086pii
S0006-3495(01)75776-1journal_volume
81pub_type
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