Conductivity in hydrated proteins: no signs of the fragile-to-strong crossover.
Dielectric spectroscopy studies of hydrated protein demonstrate smooth temperature variations of conductivity. This observation suggests no cusplike fragile-to-strong crossover (FSC) in the protein's hydration water. The FSC at T approximately 220 K was postulated recently on the basis of neutron scattering studies [Chen, Proc. Natl. Acad. Sci. U.S.A. 103, 9012 (2006)] and was proposed to be the main cause for the dynamic transition in hydrated proteins. Following Swenson et al. , we ascribe the neutron results to a secondary relaxation. We emphasize that no cusplike solvent behavior is required for the protein's dynamic transition.
Pawlus
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Department of Polymer Science, The University of Akron, Akron, Ohio 44321, USA.
Khodadadi
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Sokolov
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AP
D003080:Cold Temperature; D004527:Egg Proteins / Q000737:chemistry; D004553:Electric Conductivity; D004563:Electrochemistry; D005990:Glycerol / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods; D014867:Water / Q000737:chemistry*
D004527:Egg Proteins; D014867:Water; D009113:Muramidase; D005990:Glycerol