Dynamic light scattering studies of irradiated kappa carrageenan.

Autor: Abad LV; Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, Tokai, Ibaraki, Japan. abad@issp.u-tokyo.ac.jp, Ivabad@pnri.dost.gov.ph, Nasimova IR, Relleve LS, Aranilla CT, De la Rosa AM, Shibayama M
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2004 Apr; Vol. 34 (1-2), pp. 81-8.
DOI: 10.1016/j.ijbiomac.2004.03.012
Abstrakt: Investigation of the dynamic behavior of irradiated kappa carrageenan (in KCl) as a function of irradiation dose and temperature was done by dynamic light scattering (DLS). The intensity correlation function (ICF) shifted towards shorter relaxation times with increasing radiation dose as a result of radiolysis. The characteristic decay time distribution function, G(gamma), indicates the presence of fast and slow mode peaks respectively at around 0.1-10 ms and 100-1000 ms. A peak broadening of the fast mode peak in G(gamma) appeared with decreasing temperature, indicating that coil-to-helical conformational transition took place. The conformation transition temperature (CTT) decreased with increasing radiation dose. No transition was observed for kappa-carrageenan irradiated at 200 kGy. A new faster relaxation mode appeared at around 0.1-1 ms at temperatures below the CTT. This peak is found in kappa-carrageenan irradiated at doses exclusively between 75 and 175 kGy. The peak height of this mode is largest at 100 kGy which corresponds to the optimum biologic activity of kappa-carrageenan reported previously.
(Copyright 2004 Elsevier B.V.)
Databáze: MEDLINE
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