Comparison of the Characteristics of the Diamine Oxidase in the Digestice Organs of Several Teleostean Fishes

Abstract

The homogenate of the digestive organs of Platycephalus indicus, Lateolabrax japonicus, Scomber tapeinocephalus, and Seriola quinqueradiata were fractionated by DEAE-cellulose column chromatography. The fractions exhibiting diamine oxidase activity were searched and some properties of the enzymes were examined.
Three protein fractions were observed in all the chromatograms and the diamine oxidase activities which were assayed by using cadaverine as the substrate were recognized in one fraction in the chromatograms fo Platycephalus indicus and Seriola quinqueradiata, and in two fractions in the chromatograms of Lateolabrax japonicus and Scomber tapeinocephalus.
The optimal pH values of the exzymes of these fishes were at 6.1-8.0 and 7.0-8.3 when histamine and cadaverine were utilized as the substrates respectively. The enzymes examined in this investigation showed higher activity on cadaverine and putrescine than histamine and agmatime, and were inhibited strongly by aminoguanidine and slightly by EDTA.
The characteristics of the diamine oxidases in these fishes were similar to each other, and they were also identical with those of the enzymes in Scomber japonicus which had been examined in the previous investigation.