Dielectric studies of protein hydration

Pissis, P

dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:07:25Z
dc.date.available	2014-03-01T01:07:25Z
dc.date.issued	1989	en
dc.identifier.issn	0167-7322	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/9990
dc.subject.classification	Chemistry, Physical	en
dc.subject.classification	Physics, Atomic, Molecular & Chemical	en
dc.title	Dielectric studies of protein hydration	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/0167-7322(89)80084-4	en
heal.identifier.secondary	http://dx.doi.org/10.1016/0167-7322(89)80084-4	en
heal.language	English	en
heal.publicationDate	1989	en
heal.abstract	This work deals with dielectric studies of the binding modes of water in hydrated powders of the proteins casein and lysozyme by means of the thermally stimulated depolarization currents (TSDC) method in the temperature range 77-300 K. The water content was varied between 0.01 and 0.61 w/w. The measurements revealed the existence of two complex dispersions, a low-temperature dispersion with maxima in the temperature region 115-165 K and a high-temperature dispersion with maxima in the temperature region 155-280 K. Both dispersions were studied in detail by using several experimental techniques offered by the TSDC method. The low-temperature dispersion is due to the dielectric relaxation of loosely bound and free water molecules. The fractions of tightly bound, loosely bound and free water molecules are obtained from the dependence of the characteristics of this dispersion on water content. Apart from dc conductivity, two main relaxation mechanisms contribute to the high-temperature dispersion : the relaxation of polar side chains and the displacement of protons on the surface of the protein molecules, a mechanism first proposed by Careri and coworkers. Both mechanisms are strongly affected by the presence of water. They are characterized by distributions of relaxation times. © 1989.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Journal of Molecular Liquids	en
dc.identifier.doi	10.1016/0167-7322(89)80084-4	en
dc.identifier.isi	ISI:A1989CA86900021	en
dc.identifier.volume	41	en
dc.identifier.issue	C	en
dc.identifier.spage	271	en
dc.identifier.epage	289	en