Zinc and alkaline phosphatase in developing rat oral mucosa

Alkaline phosphatases (AlkPase) of many different tissues and species have been shown to be zinc metalloenzymes. Specific regions of rat oral mucosa have a high activity of AlkPase. Combined autoradiography and enzyme histochemistry showed that they also retained injected radioactive zinc (65Zn). The AlkPase activity was inactivated by EDTA and reactivated with zinc. However, it could not be verified by polyacrylamide gel electrophoresis combined with radioactivity measurements and enzyme analysis that the 65Zn uptake of oral mucosa was incorporated in the AlkPase molecule.