Charge Redistribution in Adenosylribosyl Transferase Caused by Substitution of a Single Amino Acid Residue

Abstract

Abstract Dielectric measurements in the frequency range 105-108 Hz were performed on wild-type (wt) adenosylribosyl transferase and a mutant enzyme. The analysis of the dielectric relaxation curve allowed the estimation of the hydrodynamic radius and of the electric dipole moment. The first parameter remained unchanged in wt and mutant protein. The dipole moment of the mutant, however, was significantly increased. Implications on the electrostatic interactions between enzyme and substrate are discussed.