Abstract
As proteins and other biomolecules consisting of amino acid residues require external additives for their dissolution and recrystallization, it is important to have information about how such additives interact with amino acids. Therefore we have studied the interactions of simple model amino acids with the additives urea and guanidine hydrochloride in aqueous solutions at 298.15 K, using vapor pressure osmometry. During the measurements, the concentration of urea was fixed as ∼2 mol⋅kg−1 and that of guanidine hydrochloride was fixed as ∼1 mol⋅kg−1 whereas the concentrations of amino acids were varied. The experimental water activity data were processed to get the individual activity coefficients of all the three components in the ternary mixture. Further, the activity coefficients were used to get the excess Gibbs energies of solutions and Gibbs energies for transfer of either amino acids from water to aqueous denaturant solutions or denaturant from water to aqueous amino acid solutions. An application of the McMillan-Mayer theory of solutions through virial expansion of transfer Gibbs energies was made to get pair and triplet interaction parameter whose sign and magnitude yielded information about amino acid–denaturant interactions, relative to their interactions with water. The pair interaction parameters have been further used to obtain salting constants and in turn the thermodynamic equilibrium constant values for the amino acid–denaturant mixing process in aqueous solutions at 298.15 K. The results have been explained in terms of hydrophobic hydration, hydrophobic interactions and amino acid–denaturant binding.
Similar content being viewed by others
References
Kauzmann, W.: Some factors in the interpretation of protein denaturation. Adv. Protein Chem. 14, 1–59 (1959)
Tanford, C.: Isothermal unfolding of globular proteins in aqueous urea solutions. J. Am. Chem. Soc. 86, 2050–2059 (1964)
Singer, S.J.: In: Rhothfield, L. (ed.) Structure and Function of Biological Membranes. Academic Press, New York (1971)
Coleman, R.: Membrane-bound enzymes and membrane ultrastructure. Biochim. Biophys. Acta 300, 1–30 (1973)
Franks, F.: In: Franks, F. (ed.) Water—A Comprehensive Treatise, vol. IV. Plenum Press, New York (1974)
Ooi, T., Oobatake, M.: Effects of hydrated water on protein unfolding. J. Biochem. 103, 114–120 (1988)
Ooi, T., Oobatake, M., Nemethy, G., Scheraga, H.A.: Accessible surface areas as a measure of the thermodynamic parameters of hydration of peptides. Proc. Natl. Acad. Sci. USA 84, 3086–3090 (1987)
Makhatadze, G.I., Privalov, P.L.: Contribution of hydration to protein folding thermodynamics: I. The enthalpy of hydration. J. Mol. Biol. 232, 639–659 (1993)
DeKoster, G.T., Robertson, A.D.: Calorimetrically-derived parameters for protein interactions with urea and guanidine-HCl are not consistent with denaturant m values. Biophys. Chem. 64, 59–68 (1997)
Courtenay, E.S., Capp, M.W., Saecker, R.M., Record, M.T. Jr.: Thermodynamic analysis of interactions between denaturants and protein surface exposed on unfolding: interpretation of urea and guanidinium chloride m-values and their correlation with changes in accessible surface area (ASA) using preferential interaction coefficients and the local-bulk domain model. Proteins 41, 72–85 (2000)
Courtenay, E.S., Capp, M.W., Saecker, R.M., Record, M.T. Jr.: Thermodynamics of interactions of urea and guanidinium salts with protein surface: Relationship between solute effects on protein processes and changes in water-accessible surface area. Protein Sci. 10, 2485–2497 (2001)
Lee, M.-E., van der Vegt, N.F.A.: Does urea denature hydrophobic interactions. J. Am. Chem. Soc. 128, 4948–4949 (2006)
Timasheff, S.N., Xie, G.: Preferential interactions of urea with lysozyme and their linkage to protein denaturation. Biophys. Chem. 105, 421–448 (2003)
Makhatadze, G.I., Privalov, P.L.: Protein interactions with urea and guanidinium chloride a calorimetric study. J. Mol. Biol. 226, 491–505 (1992)
Schellman, J.A., Gassner, N.C.: The enthalpy of transfer of unfolded proteins into solutions of urea and guanidinium chloride. Biophys. Chem. 59, 259–275 (1996)
Miyawaki, O.: Hydration state change of proteins upon unfolding in sugar solutions. Biochim. Biophys. Acta 1774, 928–935 (2007)
Arakawa, T., Timasheff, S.N.: Preferential interactions of proteins with solvent components in aqueous amino acid solutions. Arch. Biochem. Biophys. 224, 169–177 (1983)
Arakawa, T., Timasheff, S.N.: Stabilization of protein structure by sugars. Biochemistry 21, 6536–6544 (1982)
Arakawa, T., Timasheff, S.N.: Preferential interactions of proteins with salts in concentrated solutions. Biochemistry 21, 6545–6552 (1982)
Arakawa, T., Timasheff, S.N.: The stabilization of proteins by osmolytes. Biophys. J. 47, 411–414 (1985)
Rösgen, J., Pettitt, B.M., Bolen, D.W.: Protein folding, stability, and solvation structure in osmolyte solutions. Biophys. J. 89, 2988–2997 (2000)
Courtenay, E.S., Capp, M.W., Anderson, C.F., Record, M.T. Jr.: Vapor pressure osmometry studies of osmolyte-protein interactions – Implications for the action of osmoprotectants in vivo and for the interpretation of “osmotic stress” experiments in vitro. Biochemistry 39, 4455–4471 (2000)
Qu, Y., Bolen, C.L., Bolen, D.W.: Osmolyte-driven contraction of a random coil protein. Proc. Natl. Acad. Sci. USA 95, 9268–9273 (2005)
Rösgen, J.: Molecular basis of osmolyte effects on protein and metabolites. Methods Enzymol. 428, 459–486 (2007)
Athawale, M.V., Sarupria, S., Garde, S.: Enthalpy–entropy contributions to salt and osmolyte effects on molecular-scale hydrophobic hydration and interactions. J. Phys. Chem. B 112, 5661–5670 (2008)
Street, T.O., Bolen, D.W., Rose, G.D.: A molecular mechanism for osmolyte-induced protein stability. Proc. Natl. Acad. Sci. USA 103, 13997–14002 (2006)
Stimson, E.R., Schrier, E.E.: Calorimetric studies of the interactions of guanidinium hydrochloride and potassium iodide with model amides in aqueous solution. Biopolymers 14, 509–520 (1975)
Sijpkes, A.H., Oudhuis, A.A.C.M., Somsen, G.: Enthalpies of solution of amides and peptides in aqueous solutions of urea and in N,N-dimethylformamide at 298.15 K. J. Chem. Thermodyn. 21, 343–349 (1989)
Lilley, T.H., Scott, R.P.: Aqueous solutions containing amino-acids and peptides. Part 2.—Gibbs function and enthalpy behaviour of the systems urea + glycine, urea + α-alanine, urea + α-aminobutyric acid and urea + glycylglycine at 298.15 K. J. Chem. Soc. Faraday Trans. I 72, 184–196 (1976)
Arnold, A., Lilley, T.H.: Aqueous solutions containing amino acids and peptides 14. The enthalpy of interaction of β-alanine and urea. J. Chem. Thermodyn. 17, 99–100 (1985)
Nandi, P.K., Robinson, D.R.: Effects of urea and guanidine hydrochloride on peptide and nonpolar groups. Biochemistry 23, 6661–6668 (1984)
Nozaki, Y., Tanford, C.: The solubility of amino acids and related compounds in aqueous urea solutions. J. Biol. Chem. 238, 4074–4081 (1963)
Prasad, K.P., Ahluwalia, J.C.: Heat capacities of transfer of some amino acids and peptides from water to aqueous urea solution. Biopolymers 19, 273–284 (1980)
Mishra, A.K., Prasad, K.P., Ahluwalia, J.C.: Apparent molar volumes of some amino acids and peptides in aqueous urea solutions. Biopolymers 22, 2397–2409 (1983)
Lapanje, S., Skerjanc, J., Glavnik, S., Zibret, S.: Thermodynamic studies of the interactions of guanidinium chloride and urea with some oligoglycines and oligoleucines. J. Chem. Thermodyn. 10, 425–433 (1978)
Enea, O., Jolicoeur, C.: Heat capacities and volumes of several oligopeptides in urea-water mixtures at 25 °C. Some implications for protein unfolding. J. Phys. Chem. 86, 3870–3881 (1982)
Stroth, L., Schdnert, H.: Excess enthalpies of water + diglycine or triglycine or glycyl-L-alanine + urea at 298.15 K. J. Chem. Thermodyn. 12, 653–660 (1980)
Astrand, P.-O., Wallqvist, A., Karlstrom, G.: Molecular dynamics simulations of 2 M aqueous urea solutions. J. Phys. Chem. 98, 8224–8233 (1994)
Tirado-Rives, J., Orozco, M., Jorgensen, W.L.: Molecular dynamics simulations of the unfolding of barnase in water and 8 m aqueous urea. Biochemistry 36, 7313–7329 (1997)
Grdadolnik, J., Maréchal, Y.: Urea and urea–water solutions—an infrared study. J. Mol. Struct. 615, 177–189 (2002)
Mountain, R.D., Thirumalai, D.: Molecular dynamics simulations of end-to-end contact formation in hydrocarbon chains in water and aqueous urea solution. J. Am. Chem. Soc. 125, 1950–1957 (2003)
Klimov, D.K., Straub, J.E., Thirumalai, D.: Aqueous urea solution destabilizes Aβ16–22 oligomers. Proc. Natl. Acad. Sci. USA 101, 14760–14765 (2004)
Frank, H.S., Franks, F.: Structural approach to the solvent power of water for hydrocarbons; urea as a structure breaker. J. Chem. Phys. 48, 4746–4757 (1968)
Finer, E.G., Franks, F., Tait, M.J.: Nuclear magnetic resonance studies of aqueous urea solutions. J. Am. Chem. Soc. 94, 4424–4429 (1972)
Hoccart, X., Turrell, G.: Raman spectroscopic investigation of the dynamics of urea–water complexes. J. Chem. Phys. 99, 8498–8503 (1993)
Stumpe, M.C., Grubmüller, H.: Interaction of urea with amino acids: Implications for urea-induced protein denaturation. J. Am. Chem. Soc. 129, 16126–16131 (2007)
Kurhe, D.N., Dagade, D.H., Jadhav, J.P., Govindwar, S.P., Patil, K.J.: Studies of enthalpy-entropy compensation, partial entropies, and Kirkwood-Buff integrals for aqueous solutions of glycine, l-leucine, and glycylglycine at 298.15 K. J. Phys. Chem. B 113, 16612–16621 (2009)
Robinson, R.A., Stokes, R.H.: Electrolyte Solutions, 2nd edn. Butterworths, London (1959)
Patil, K., Pawar, R., Dagade, D.: Studies of osmotic and activity coefficients in aqueous and CCl4 solutions of 18-crown-6 at 25 °C. J. Phys. Chem. A 106, 9606–9611 (2002)
Dagade, D.H.: Studies of thermodynamic and transport properties of 18-crown-6 in aqueous, nonaqueous and aqueous electrolytic solutions, Ph.D. thesis, Shivaji University, Kolhapur (2004)
Terdale, S.S., Dagade, D.H., Patil, K.J.: Thermodynamic studies of molecular interactions in aqueous α-cyclodextrin solutions: application of McMillan-Mayer and Kirkwood-Buff theories. J. Phys. Chem. B 110, 18583–18593 (2006)
Ellerton, H.D., Dunlop, P.J.: Activity coefficients for the systems water–urea and water–urea–sucrose at 25° from isopiestic measurements. J. Phys. Chem. 70, 1831–1837 (1966)
Schrier, M.Y., Schrier, E.E.: Osmotic and activity coefficients of aqueous guanidine hydrochloride solutions at 25 °C. J. Chem. Eng. Data 22, 73–74 (1977)
Macaskill, J.B., Robinson, R.A., Bates, R.G.: Osmotic coefficients and activity coefficients of guanidinium chloride in concentrated aqueous solutions at 25 °C. J. Chem. Eng. Data 22, 411–412 (1977)
Wen, W.-Y., Chen, C.L.: Activity coefficients for two ternary systems: water–urea–tetramethylammonium bromide and water–urea–tetrabutylammonium bromide at 25°. J. Phys. Chem. 73, 2895–2901 (1969)
Terdale, S.S., Dagade, D.H., Patil, K.J.: Activity and activity coefficient studies of aqueous binary and ternary solutions of 4-nitrophenol, sodium salt of 4-nitrophenol, hydroquinone and α-cyclodextrin at 298.15 K. J. Mol. Liq. 139, 61–71 (2008)
Bower, V.E., Robinson, R.A.: The thermodynamics of the ternary system: urea–sodium chloride–water at 25°. J. Phys. Chem. 67, 1524–1527 (1963)
Robinson, R.A., Stokes, R.H.: Activity coefficients of mannitol and potassium chloride in mixed aqueous solutions at 25°. J. Phys. Chem. 66, 506–507 (1962)
Patil, K., Dagade, D.: Studies of activity coefficients for ternary systems: water + 18-crown-6 + alkali chlorides at 298.15 K. J. Solution Chem. 32, 951–966 (2003)
Terdale, S., Dagade, D., Patil, K.: Activity coefficient studies in ternary aqueous solutions at 298.15 K: H2O + α-cyclodextrin + potassium acetate and H2O + 18-crown-6 + hydroquinone systems. J. Chem. Eng. Data 54, 294–300 (2009)
Desnoyers, J.E., Billon, M., Leyer, S., Perron, G., Morel, J.-P.: Salting out of alcohols by alkali halides at the freezing temperature. J. Solution Chem. 5, 681–691 (1976)
Samoilov, O.Y.: Structure of aqueous electrolyte solutions. Ives, D.J. (trans.). Consultants Bureau, New York (1965)
Fetterly, L.C.: In: Mandel-Corn, L. (ed.) Non-Stoichiometric Compounds, pp. 491–567. Academic Press, New York (1964)
Whitney, P.L., Tanford, C.: Solubility of amino acids in aqueous urea solutions and its implications for the denaturation of proteins by urea. J. Biol. Chem. 237, PC1735–PC1737 (1962)
Meyer, M.L., Kauzmann, W.: The effects of detergents and urea on the rotatory dispersion of ovalbumin. Arch. Biochem. Biophys. 99, 348–349 (1962)
Rosenberg, R.M., Rogers, D.W., Haebig, J.E., Steck, T.L.: The interaction of serum albumin with ethanol. Arch. Biochem. Biophys. 97, 433–441 (1962)
Jirgensons, B.: Optical rotatory dispersion and conformation of various globular proteins. J. Biol. Chem. 238, 2716–2722 (1963)
Franks, F., Redley, M.D.: Solute-solute interactions in dilute aqueous solutions Part-IV: Microcalorimetric study of ternary mixtures of urea and hydrophobic species. J. Chem. Soc. Faraday Trans. I 77, 1341–1349 (1981)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kurhe, D.N., Dagade, D.H., Jadhav, J.P. et al. Thermodynamic Studies of Amino Acid–Denaturant Interactions in Aqueous Solutions at 298.15 K. J Solution Chem 40, 1596–1617 (2011). https://doi.org/10.1007/s10953-011-9737-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10953-011-9737-8