ELECTROSTATIC CONTROL OF OXIDATIVE DEAMINATION CATALYZED BY BOVINE SERUM AMINE OXIDASE

The ionic-strength-dependence of steady-state kinetic parameters (k(c) and K-m') for non-biogenic (benzylamine, butylamine) and biogenic (sp ermine, spermidine) amines has been measured in the bovine serum amine oxidase reaction. The catalytic rate constant (k(c)) values are simil ar (0.9-2.5 s(-1)) for all the substrates studied and are almost const ant over the experimental ionic strength range (24-155 mM). In contras t, K-m' values are in the range 6-2300 mu M and undergo a 4-12-fold in crease with increasing ionic strength, parallelled by a decrease in ca talytic efficiency. From an analysis of the k(c) and K-m' values and t heir dependence on ionic strength, we conclude that more than one nega tive site is involved in the binding of these amines and that the rela tive dielectric constant of the binding site is lower than that of aqu eous solutions.