Purification of 12-O-tetradecanoylphorbol-13-acetateinduced ornithine decarboxylase from mouse epidermis

1. 1. Ornithine decarboxylase was purified at least 1500-fold from mouse epidermis pretreated with five consecutive doses of 12-O-tetradecanoylphorbol-13-acetate and 3-isobutyl-l-methylxanthine at 3- to 4-day intervals. 2. 2. Following DEAE-cellulose chromatography and ammonium sulfate precipitation, ornithine decarboxylase was purified further by affinity chromatography. 3. 3. Ornithine decarboxylase was then radioactively labeled by covalently binding [³H]-α-difluromethylornithine to the enzyme following polyacrylamide gel electrophoresis under non-denaturing conditions. 4. 4. Following sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver staining of protein, a band was identified that corresponded to a molecular weight of approx. 56,000, coincident with a peak of radioactivity. 5. 5. This is the first study to purify ornithine decarboxylase from mouse epidermis,.