Água ligada e propriedades elétricas da Lisozima

Abstract

Using four differents techniques we have analysed the dielectric and structural properties of lysozyme with hydration below 40mg H2O/g prot. All the observed effects were related to the presence of bound-water molecules at the hydrophilic sites on the surface of the macromolecu1e. From the spectra of Isotermic Discharge we observe the existance of two differents bounding sites, both with characteristic frequency, measured at room temperatures, in the range of 10-2Hz, indicating that the molecules are strongly bounded. The despolarization process might be due to two effects: rotation and sorption of the H2O molecules. The experimental data show that the main effects are those of sorption. The sorption activation energies, 0.34 and 0.55eV , suggest that the H2O molecules are bounded by one or two hydrogen bounds to the surface of lysozyme.