ABSTRACT
This chapter focuses on the principles of catalytic function of enzymes in monophasic organic media, the consequences of removing bulk water from an enzymic reaction mixture, the mechanistic and kinetic behavior of enzymes in nonaqueous media, and the factors that must be taken into account for choosing the proper solvent and enzyme preparation for a given reaction. A description of applications of commercially relevant enzymes in monophasic organic solvents follows this discussion. Because of the importance of water in enzyme function, it is necessary to review the role of water in enzyme structure and function, and to describe the consequences of removing bulk water from an enzyme reaction mixture. The differences between adsorbed and bulk water, particularly the increase in hydrophobicity and the decrease in hydrogen bonding character, indicate that water may be replaced by solvents with physicochemical properties intermediate between water and hydrophobic organic solvents without significantly affecting catalytic activity.
