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Solvent‐induced lysozyme gels: Effects of system composition and temperature on structural and dynamic characteristics
Author(s) -
da Silva Marcelo A.,
Farhat Imad A.,
Arêas Elizabeth P. G.,
Mitchell John R.
Publication year - 2006
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20561
Subject(s) - chemistry , lysozyme , tetramethylurea , solvent , mass fraction , thermodynamics , analytical chemistry (journal) , chromatography , organic chemistry , biochemistry , physics
The gelation process of lysozyme in water/tetramethylurea in the presence of salt was investigated as a function of temperature and system composition by rheology, infrared spectroscopy, and microcalorimetry. Times and temperatures of gelation were determined from the variation of the storage (G′) and loss (G′′) moduli. It was found that gelation times follow exponential decays with both protein and tetramethylurea (TMU) concentrations and with temperature. The activation energy for the overall process shows a linear dependence on TMU mass fraction. A strongly increased β‐sheet content and reduced α‐helix occur with the increase of TMU concentration in the binary solvent. Also, a linear decrease of lysozyme denaturation temperature and enthalpy on TMU concentration is found for the TMU mass fraction up to 0.5, above which no denaturation signal can be detected. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 443–454, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com