Research Of Protein Denaturation Process By Dielectric Spectroscopy

The study of protein denaturation can help to reveal profoundly the nature and mechanism ofbiological phenomena. In Protein denaturation process, the secondary structure will change, many ways candetect these changes. Common methods have fluorescence spectroscopy, Fourier transform infraredspectroscopy (FTIR), circular dichroism method (CD) and-ray diffractio-n method (X-ray), etc., as thesemethods in the study of protein denaturation have some shortcomings and deficiencies.They do notaccurately reflect protein denaturation of all information.Dielectric spectra coveres a total of10-5to108orders of magnitude Diego l4very wide frequencyrange.It is one of the most effective way to study of polymer structure and polarity of solid movement ofspace charge. Of course, in the frequency range of different frequencies of the measuring principle and theinstruments used are different. Dielectric spectroscopy methods to measure the dielectric material ofdielectric constant and dielectric loss with frequency or temperature changes with the temperaturerelationship.In this thesis, using the dielectric spectroscopy method study the denaturation of proteins, andcharacterization of protein denaturation parameters, this approach tests the feasibility of measuring proteindenaturation. First Novocontrol broadband impedance analysis instrument of egg white and yolk in the lowtemperature range dielectric spectroscopy measurements, the process of egg white and egg yolk denaturedat high temperature range dielectric spectroscopy measurements. Attempt to analyze the impact oftemperature on the complex permittivity of egg white and yolk, and egg white and degenerationdegeneration process in the change of the complex permittivity of the corresponding characteristics.Experimental results show that in the300K~90K the egg white and yolk of heating and coolingprocess to the real part of permittivity ε ’and imaginary part ε " have two of the more obvious changes,corresponds to the corresponding relaxation process and the process of changephase transition, but thewarming in the relaxation process of the transformation process of the corresponding temperature is higherthan the corresponding temperature in the cooling. Two heating and cooling is consistent with the real partof the dielectric constant ε ’and imaginary part ε "with temperature T changesthis illustrates,not only theinner layer of egg white in300K~90K and irreversible changes, and also dielectric spectroscopy methodsto measure the inner layer of egg white is feasible, the data is reliable and repeatable. Samples in300K~350K after first warming350K the inner of the two heating and cooling process in the egg white and yolkprotein.In the first heated, denaturation does not completely denatured or denaturation process is notcompletely carried out, in the second heating protein continued degeneration. Protein denaturation processis a gradual process, and can not be done at a certain temperature, but occur in a certain temperature range.This research show that the dielectric spectroscopy method can effectively detect the egg white andyolk with temperature change and change process, so providing an effective means of measurement for thestudy of protein colloid; the same time, research data and conclusionsalso provide a reference for in-depthstudy of the protein colloids of the nature and structure varies with temperature changes.