%0 Journal Article
%T Pressure- and Urea-Induced Denaturation of Bovine Serum Albumin: Considerations about Protein Heterogeneity
%A Douglas Ricardo Norberto
%A Joelma Mauricio Vieira
%A Ancelmo Rabelo de Souza
%A Jose Ailton Conceicao Bispo
%A Carlos Francisco Sampaio Bonafe
%J Open Journal of Biophysics
%P 4-14
%@ 2164-5396
%D 2012
%I Scientific Research Publishing
%R 10.4236/ojbiphy.2012.21002
%X Urea denatures proteins at different concentrations, depending on the experimental conditions and the protein. We in-vestigated the pressure-induced denaturation of bovine serum albumin (BSA) in the presence of subdenaturing concen-trations of urea based on a two-state equilibrium. Pressure-induced denaturation was enhanced at urea concentrations ([U]) of 3.5 M to 8.0 M, with the free energy of denaturation at atmospheric pressure   ranging from +5.0 to ¨C2.5 kJ/mol of BSA. The m values appeared to be biphasic, with m1 and m2 of 0.92 and 2.35 kJ mol¨C1?M¨C1, respectively. Plots of  versus ln[U] yielded values of u, the apparent stoichiometric coefficient, of 1.68 and 6.67 mol of urea/mol of BSA for m1 and m2, respectively. These values were compared with the m and u values of other monomeric proteins reported in or calculated from the literature. The very low values of u systematically observed for proteins were suggestive of heterogeneity in the free energy of denaturation. Thus, a u value of 140 mol of urea/mol of BSA may indicate the existence of a heterogeneous molecular population with respect to the free energy of dena-turation.
%K Apparent Stoichiometric Coefficient
%K Bovine Serum Albumin
%K High Pressure-Induced Denaturation
%K Protein Heterogeneity
%K Urea-Induced Denaturation
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=17114