Biochemical Thermodynamics

Our research involves thermodynamic studies of industrially and biologically important enzyme-catalyzed reactions. Equilibrium and calorimetric measurements are performed as functions of pH, ionic strength, and temperature using high performance liquid chromatography, gas chromatography, microcalorimetry and other techniques. Current efforts are focused on reactions in the shikimate and chorismate pathways and biocatalysis in non-aqueous media. Experimental aspects of these studies include: (i) the development of methodology for the separation and characterization of substances involved in a study (ii) obtaining sufficient enzyme activity to carry out a given reaction and demonstrate that equilibrium has been achieved; and (iii) determination of optimum conditions for the calorimetric measurements. Because of its wide range applicability for biochemical analysis, high performance liquid chromatography has been and continues to be a principal to be used for this research.

Publications

• "Saturation molalities and standard molar enthalpies of solution of cytidine(cr), hypoxanthine(cr), thymidine(cr), thymine(cr), uridine(cr) and xanthine(cr) in H₂O(l).” Y.B. Tewari, P.D. Gery, M.D. Vaudin, A.D. Mighell, R. Klein and R.N. Goldberg, J. Chem. Thermodyn 36, 645-658, 2004.

• “A thermodynamic study of the lipase-catalyzed transesterification of benzyl alcohol and butyl acetate in supercritical carbon dioxide media.” Y.B. Tewari, T. Ihara, K.W. Phinney and M.P. Mayhew, J. Mol. Catal. B: Enzymatic, 30, 131-136, 2004

• “A thermodynamic study of the ketoreductase-catalyzed reduction of 2-alkanones in non-aqueous solvents.” Y.B. Tewari, M.M. Schantz, K.W. Phinney and J.D. Rozzell, J. Chem. Thermodyn. 37, 89-96, 2005.

• Thermodynamics of the hydrolysis reactions of nitriles.” Y.B. Tewari and R.N. Goldberg, J. Chem. Thermodyn.(Press).