On the Reaction Mechanism of Crotalus adamanteus l-Amino Acid Oxidase

Abstract

Abstract The flavin semiquinoid form of l-amino acid oxidase has been found not to be reduced further by l-amino acids. By rapid reaction spectrophotometry, the long wave length-absorbing intermediate formed transiently in the reduction of the enzyme by l-amino acids has been shown not to be attributable to the uncombined semiquinoid species, but to involve also some contribution from the substrate. Kinetic studies of the reaction show that a ternary complex of enzyme, substrate, and oxygen is involved in the over-all catalytic reaction. The significance of these findings in terms of the catalytic reaction mechanism is discussed.