E. P. Hade and C. Tanford, “Isopiestic Compositions as a Measure of Preferential Interactions of Macromolecules in Two-Component Solvents. Application to Proteins in Concentrated Aqueous Cesium Chloride and Guanidine Hydrochloride,” Journal of the American Chemical Society, USA, Vol. 89, No. 19, 1967, pp. 5034-5040. doi:10.1021/ja00995a036

has been cited by the following article:

• TITLE: Pressure- and Urea-Induced Denaturation of Bovine Serum Albumin: Considerations about Protein Heterogeneity

  AUTHORS: Douglas Ricardo Norberto, Joelma Mauricio Vieira, Ancelmo Rabelo de Souza, Jose Ailton Conceicao Bispo, Carlos Francisco Sampaio Bonafe

  KEYWORDS: Apparent Stoichiometric Coefficient; Bovine Serum Albumin; High Pressure-Induced Denaturation; Protein Heterogeneity; Urea-Induced Denaturation

  JOURNAL NAME: Open Journal of Biophysics, Vol.2 No.1, January 19, 2012

  ABSTRACT: 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 –2.5 kJ/mol of BSA. The m values appeared to be biphasic, with m1 and m2 of 0.92 and 2.35 kJ mol–1?M–1, 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.