Dielectric dispersion of albumins. Studies of denaturation by dielectric measurement

Abstract

The dielectric dispersion of bovine serum albumin and ovalbumin was studied before and after urea denaturation. Native bovine serum albumin was found to have an exceedingly small dielectric increment indicating that the charge distribution in this protein has a remarkably high degree of symmetry. The dielectric increment and the relaxation time increase on the addition of high concentration of urea. However, the dielectric properties of denatured bovine serum albumin are not drastically different from that of native protein indicating that urea denatured bovine serum albumin still maintains considerably large amounts of original folding of peptide chains. In contrast to bovine serum albumin, ovalbumin undergoes more pronounced change in the dielectric properties but it is more likely due to the formation of aggregates after urea denaturation, rather than the unfolding of peptide chain in individual molecules.