خالص سازي آنزيم آلكالين فسفاتاز از جفت انساني

The Purification of Alkaline Phosphatase from Human Placenta

Alkaline phosphatase , an orthophosphoric monoester phosphohydrolase Ec 3.1. 3.1. , is a glycoprotein dimer . It is active in alkaline PH and needs mg2+ ion as an activator . This membrane-bound enzyme is widely distributed in nature . In this study , it was purified from human placenta in seven steps . Placenta was homogenated and the enzyme was extracted through following steps : Butanol extraction , filtration on sephadex G200 , ammonium sulfate precipitation , aceton precipation and DEAE cellulose chromatography with a gradient of sodium chloride . A peak of the enzyme activity at sodium chloride concentrations of 0.087 to 0.093 mg was observed on DEAE cellulose chromatography . The specific activity of the enzyme and purification factor were observed to be 209.9 U/mg and 611.8 respectively. At the final steps of preparative electrophoresis , the purified enzyme was subjected to polyacrylamide disc gel electrophoresis . P-nitrophenyl phosphate was used , instead of N-naphthyl phosphate , to stain alkaline phosphatase . The appearance of a yellaw band proved the purification of the enzyme .