Using UHF-dielectrometry to study protein structural transitions

Textures on the surface of BSA films with different concentrations of sodium halides and water state in solution

“…The real ε′ and imaginary ε″ parts of complex permittivity of the BSA solution (10 mg/ml), solutions of sodium halides NaF, NaCl, and NaBr (0.4 M), and water-BSA-salt systems (10 mg/ml BSA and 0.4 M salt) were measured using the microwave dielectric method [ 21 ] at a frequency of 9.2 GHz and a temperature of 22.9°C ± 0.1°C. Corrections for the presence of inorganic ions were made on the basis of conductivity measurements at a frequency of 1 kHz.…”

“…Therefore, the aim of this work is to study the formation of textures on the surface of films from solutions containing BSA and sodium halide salts (NaF, NaCl, and NaBr), as well as to study the state of water in the water-BSA-salt system and the change in the BSA conformation. Microwave dielectrometry was used to study the structure of water [ 21 ], and the conformational state of the BSA was studied by UV and fluorescence spectroscopy.…”

Textures on the surface of BSA films with different concentrations of sodium halides and water state in solution

“…The real ε′ and imaginary ε″ parts of complex permittivity of the BSA solution (10 mg/ml), solutions of sodium halides NaF, NaCl, and NaBr (0.4 M), and water-BSAsalt systems (10 mg/ml BSA and 0.4 M salt) were measured using the microwave dielectric method [21] at a frequency of 9.2 GHz and a temperature of 22.9°C ± 0.1°C. Corrections for the presence of inorganic ions were made on the basis of conductivity measurements at a frequency of 1 kHz.…”

Influence of cancer disease on dielectric characteristics of structural-functional state of erythrocyte membranes

“…Using the values of indicators of an actual (ε′) and imaginary (ε′′) parts of complex dielectric permeability of suspension of erythrocytes and suspension of erythrocyte ghosts of donors and cancer patients, the dielectric relaxation frequency (f d ) of the water molecules in studied systems was calculated by the formula: f d =f (ε′-ε ∞ )/ε′′, where f d -and f -dielectric relaxation frequency and microwave field frequency respectively, ε ∞ =5,5 (dielectric permeability of the studied objects in IR-diapason) [31]. Dielectric relaxation frequency (f d ) of the water molecules is a parameter that characterizes the mobility of molecules in UHF field and so the degree of its interaction with surrounding solution.…”

“…Examination of dielectric characteristics of suspensions of erythrocytes and its ghosts in temperature area from 1 to 46 o C was carried out on UHF-dielecrometer of resonator type on frequency 9,2 Ghz [30, 31]. Transition from values ε′ and ε′′ directly measured in experiment to the value f d -dielectric relaxation frequency of the water in solution was realized with a help of Debye equation [30,31]. The activation energy of dipole relaxation ∆F of the water molecules in studied systems was get from the ratio [32]:…”