a1 Protein Engineering Research Institute, Furuedai, Suita, Osaka 565. Japan
Electrostatic effects play an essential role in specific molecular recognition and molecular assembly in many biologically important molecules. The specific electric field at the active site also regulates the catalytic reaction of a protein. Moreover, intramolecular or inter-subunit electrostatic interactions, such as saltbridges, hydrogen bonds, and charge-dipole interactions, are considered to work to stabilize protein molecules. Those electrostatic roles recently observed in proteins are reviewed with a description of the origins and principles of electrostatic forces, and analyses will be made using simple models to illuminate the physical basis.