Volumetric properties and surface tension of aqueous 3-chloropropan-1-ol and aqueous 3-chloropropan-1,2-diol, and correlation of their effect on protein stability

Densities, apparent molar volumes, and surface tension of aqueous 3-chlorop ropan-1-ol and 3-chloropropan-1,2-diol were determined at temperatures from (283.08 to 308.15) K. The results of the volumetric measurements have been used to calculate the following thermodynamic quantities at T = 298.15 K. For 3-chloropropan-1-ol(aq): V-2,m(o) = (79.79 +/- 0.23) cm(3) . mol(-1); ( partial derivative V/(o)(2,m)/partial derivative T)(p) = (10.31 +/- 1.28) . 10(-2) cm(3) . K-1 . mol(-1); (partial derivative(2)V(2,m)(o)/partial deri vative T-2)(p) = (4.16 +/- 1.46) . 10(-3) cm(3) . K-2 . mol(-1), and for 3- chloroproan 1,2-diol(aq): V-2,m(o) = (80.62 +/- 0.23) cm(3) . mol(-1); (par tial derivative V-2,m(o)/partial derivative T)p = (8.499 +/- 1.080) 10(-2) cm(3) . K-1 . mol(-1); (partial derivative(2)V(2,m)(o)/partial derivative T -2)(p) = (1.610 +/- 0.67) . 10(-3) cm(3) . K-2 . mol(-1). The preferential interaction parameters of the interaction of 3-chloropropan-1-ol and 3-chlo ropropan-1,2-diol with two structurally homologous proteins then egg-white lysozyme and alpha-lactalbumin) have been calculated by correlating the mea sured surface tension data to the surface areas of these proteins. The data on the measured apparent molar volumes and surface tension of aqueous 3-ch loropropan-1-ol and 3-chlorupropan-1,2-diol, in combination with the therma l denaturation data and surface area values of hen egg-white lysozyme from literature, clearly indicate a parallel trend in changes in the surface ten sion of water, partial molar volume, and ability to alter the thermal stabi lity of these proteins. (C) 2000 Academic Press.