A study of alkaline phosphatase in rabbit periodontium

Abstract

Alkaline phosphatase (APase) was partially purified from rabbit periodontal membranes by buthanol extraction, ethanol fractionation and DEAE Sephadex A50 ion exchange column chromatography. And then some enzymatic properties were investigated. The alkaline phosphatase activity was measured with p-nitrophenylphosphate (p-NPP) used as the substrate at pH 9.5.
1) The enzyme activity was separated into three peaks by DEAE Sephadex A50 chromatography. These enzymes hydrolyzed pyrophosphate (PPi), and two of them hydrolyzed adenosine tri-phosphate (ATP).
2) Each APase was strongly inactivated by EDTA and reversibly reactivated up to 70% by Zn²⁺.
3) Each APase activity was also inhibited by several inhibitors, such as Zn²⁺, pyrophosphate. Their inhibition patterns seemed biphasic.