Hepatic ornithine decarboxylase from the frog, Rana negromaculata: dietary induction, purification and some properties.

1. In the liver of the frog, Rana negromaculata, the activity of ornithine decarboxylase (ODC) was induced by dietary stimuli and was rapidly lost upon intraperitoneal injection of cycloheximide or putrescine. 2. Frog liver ODC, purified by DEAE-Cellulofine and immunoaffinity column chromatographies, was used in a comparative study with mouse kidney ODC, also purified by the same method. 3. The purified frog ODC showed three bands on SDS-polyacrylamide gel electrophoretic analysis, as confirmed by [3H]alpha-difluoromethylornithine binding. 4. Frog ODC was found to be similar to mouse enzyme in some properties, for example molecular weight, immunoreactivity and inhibition by rat antizyme, except for a slightly higher Km value for ornithine.