Experimental Study on Conformational Changes of Lysozyme in Solution Induced by Pulsed Electric Field and Thermal Stresses

Abstract

The responses of proteins to different forms of stress are not well understood at the present time. The "nonthermal" effect of electric field on proteins has recently become an area of great theoretical and practical interest. Possible effects of pulsed electric field on proteins have been predicted by theoretical simulations. However, there is still a lack of experimental reports. In this work, experimental studies were carried out to investigate and compare the effects of 3.5 x 10(6) V/m pulsed electric field and thermal stresses on the conformational changes of lysozyme in solution. The changes in secondary structure and conformation of disulfide linkage (S-S) of lysozyme were investigated experimentally by circular dichroism analysis and micro-Raman spectra. The motions of tryptophan and tyrosine side chains in lysozyme were also evaluated. From the experimental data, different actions of electric field and thermal stresses on the protein were discovered.