Effect of Organic Solvents on the Binding of Competitive Inhibitor Proflavin and Storage Stability of Bovine Pancreatic α-Chymotrypsin pp. 97-134
Authors: (Vladimir A. Sirotkin, Kazan State University, A.M. Butlerov Chemical Institute, Kazan, Russia)
Abstract: The binding of competitive inhibitor proflavin and the storage stability of bovine pancreatic α-chymotrypsin in water-organic mixtures were studied in the entire range of thermodynamic water activities at 25oC. Acetonitrile, dioxane, tetrahydrofuran, and acetone were used as model solvents due to their ability to vary significantly the size, polarity, denaturation capacity, and hydrophobicity. The state of water hydrogen bond network in organic solvents was characterized by thermodynamic and spectroscopic data. The absorption spectra of water in organic solvents were measured by FTIR spectroscopy. The state of water in organic solvents was defined in terms of variations in the integral intensity of water and the contour shape of the band of OH stretching vibrations. Excess chemical potentials, partial molar enthalpies, and entropies of water and organic solvents were simultaneously evaluated at 25oC.