Immunochemical studies of l-amino acid oxidase

Abstract

Differences were found between l-amino acid oxidase ( l-amino acid:O 2 oxidoreductase (deaminating), EC 1.4.3.2) and its warm-inactivated and frozen-inactivated forms by complement fixation and immunoelectrophoresis. The enzyme inactivated by freezing had more alteration than that treated at 38°. These immunologically detected differences disappeared upon reactivation. Isozyme A also differed from the total mixture of isozymes. The antibody to the native does not inhibit enzymic activity but does protect against warm inactivation. Antibody also shifted the equilibrium between active and inactive forms towards the active form and accelerated reactivation of both warm and frozen forms. Normal γ-globulin also shifts the above equilibrium toward the active form.