Effects of Metal Ions on Alkaline Phosphatase of Calf Intestine
Author of the article:ZHANG Ying, YU Tong, ZHAO Xin-ping*, GAO Ju
Author's Workplace：(School of Life Sciences, Key Laboratory of Bio-resources and Eco-environment Ministry of Education, Sichuan University, Chengdu 610065, China)
Key Words：calf intestine; alkaline phosphatase; metal ions
Abstract：Alkaline phosphatase (ALP, EC 3·1·3·1) is a non-specific phosphomononoesterase that functions through the phosphosery1 intermediate to produce a free group to other alcohols. ALPs have been extensively investigated and widely used as biochemical and diagnostic reagents, among which ALP from calf intestine is an ideal one for its extensive uses in genetic engineering. We choose calf intestine as a resource of ALP for the purpose of applying ALP to biochemical and clinical reagents. Calf intestine ALP was separated by extraction of n-butyl alcohol, amonanium sulfate precipitation, ion exchange through DEAE-32 chromatography column, gel filtration chromatography through Sephadex G-150 column and DEAE-32 chromatography column. ALP was detected as one band through SDS-Polyacrylamide gel electrophoresis, indicating its homogeneity in components. The ultimate specific activity of purified enzyme was measured as 48.87 U/mg. Study of various metal ions demonstrates that the positive monovalent cations Na+, K+ had no effect on the enzymes; Ni2+, Co2+ had no obvious effect on the enzyme, Mg2+, Mn2+, Ca2+ activated the enzyme while Zn2+, Cu2+, Pb2+, Cd2+ inhibited the enzyme.