ABSTRACT
This chapter proposes a set of rules for enhancing the stability and activity of enzymes in nonaqueous solvents by protein engineering. It is argued that significant improvements in enzyme stability in organic solvents can be achieved through alterations in amino acid sequence. It synthesizes results from hydration and solution studies to formulate a set of design criteria for engineering nonaqueous solvent-stable enzymes. The connections between structural features and therefore the types of amino acid alterations that should result in improved stability in aqueous solution and stability in nonaqueous solvents will be explored. Careri and coworkers have correlated data on the hydration of lysozyme powders in an effort to obtain a unified picture of the hydration process. Hydrogen bonding makes significant contributions to formation of secondary structure and stability, in addition to placing tight constraints on the conformations of folded proteins. Electrostatic interactions leading to formation of ion pairs contribute to the stability of folded proteins.
