| Abstract: | A systematic procedure is provided for determination of D-amino acid oxidase (EC 1.4.3.3) activity in fish tissues. Activity was surveyed in crude liver homogenates of twenty-three species of fish. Activity ranged from 0-047 to 3-12 units (ρmol product produced per min) per gram wet weight of tissue. Activity was highest in liver, with significant levels occurring in kidney and pyloric caecae. It was below the limit of detection in brain, heart, spleen, testis, gill filaments, and muscle. Some properties of the enzyme from sockeye salmon, Oncorhynchus nerka (Walbaum), were studied. Knowledge of occurrence and levels of D-amino acid oxidase in fish may be useful to fish aquaculturists contemplating supplementation of feed with racemic mixtures of amino acids. |
