For many years, chemical modification of enzymes has been a key technique to elucidate the residues involved in their catalytic activity. More recently, chemical modification has also been a useful tool in applied biochemistry (e.g., enzyme stabilization by modification of key residues, by intramolecular cross-linking, and so on) (1 –6 ). From this latter point of view, chemical modification continues to be an excellent approach for improvement of immobilized enzyme engineering (enzyme stabilization, modulation of enzyme catalytic properties, and so on), and an additional complementary technique to improve the properties of genetically engineered enzymes.
