Kinetic studies with alkaline phosphatase in the presence and absence of inhibitors and divalent cations
Article first published online: 3 NOV 2006
Copyright © 2002 International Union of Biochemistry and Molecular Biology, Inc.
Biochemistry and Molecular Biology Education
Volume 30, Issue 6, pages 401–407, November 2002
How to Cite
Dean, R. L. (2002), Kinetic studies with alkaline phosphatase in the presence and absence of inhibitors and divalent cations. Biochem. Mol. Biol. Educ., 30: 401–407. doi: 10.1002/bmb.2002.494030060138
- Issue published online: 3 NOV 2006
- Article first published online: 3 NOV 2006
- Manuscript Revised: 15 JUL 2002
- Manuscript Received: 7 JUN 2002
- Alkaline phosphatase;
- enzyme kinetics;
- enzyme inhibition;
- divalent cation cofactors
A very robust and inexpensive kinetic assay for determining rates of hydrolysis of p-nitrophenyl phosphate by the enzyme alkaline phosphatase is presented. The reaction increases in rate with increase in pH. The enzyme is competitively inhibited by the reaction products, uncompetitively inhibited by L-phenylalanine, and responds to the presence of two cofactors, magnesium and zinc ions. The reaction rate increases as Mg2+ concentration is increased from 1–5 mM. With increasing Zn2+ concentration, the reaction rate is stimulated and then depressed. Experimental work on the interaction between Mg2+ and Zn2+ in the reaction is suggested for more capable students.