The effect of zinc and magnesium ions on the activity of kidney alkaline phosphatase

The arginine-specific reagents 2,3-butanedione and phenylglyoxal inactivate pig kidney alkaline phosphatase. As inactivation proceeds there is a progressive fall in Vmax. of the enzyme, but no demonstrable change in the Km value for substrate. Pi, a competitive inhibitor, and AMP, a substrate of the enzyme, protect alkaline phosphatase against the arginine-specific reagents. These effects are explicable by the assumption that the enzyme contains an essential arginine residue at the active site. Protection is also afforded by the uncompetitive inhibitor NADH through a partially competive action against the reagents. Enzyme that has been exposed to the reagents has a decreased sensitivity to NADH inhibition. It is suggested that an arginine residue is important for NADH binding also, although this residue is distinct from that at the catalytic site. The protection given by NADH against loss of activity is indicative of the close proximity of the active and NADH sites.

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Chicken Intestinal Alkaline Phosphatase

The Journal of General Physiology ◽

10.1085/jgp.43.6.1149 ◽

1960 ◽

Vol 43 (6) ◽

pp. 1149-1169 ◽

Cited By ~ 18

Author(s):

M. Kunitz

Keyword(s):

Alkaline Phosphatase ◽

Zinc Ions ◽

Magnesium Ions ◽

Intestinal Alkaline Phosphatase ◽

Reversible Inactivation ◽

Higher Temperature ◽

Kinetics Of ◽

Hydrolysis Of ◽

Zn Ions ◽

Denaturation Of Proteins

Purified chicken intestinal alkaline phosphatase is active at pH 8 to 9, but becomes rapidly inactivated with change of pH to 6 or less. Also, a solution of the inactivated enzyme at pH 4.5 rapidly regains its activity at pH 8. In the range of pH 6 to 8 a solution of purified alkaline phosphatase consists of a mixture of active and inactive enzyme in equilibrium with each other. The rate of inactivation at lower pH and of reactivation at higher pH increases with increase in temperature. Also, the activity at equilibrium in the range of pH 6 to 8 increases with temperature so that a solution equilibrated at higher temperature loses part of its activity on cooling, and vice versa, a rise in temperature shifts the equilibrium toward higher activity. The kinetics of inactivation of the enzyme at lower pH and the reactivation at higher pH is that of a unimolecular reaction. The thermodynamic values for the heat and entropy of the reversible inactivation and reactivation of the enzyme are considerably lower than those observed for the reversible denaturation of proteins. The inactivated enzyme at pH 4 to 6 is rapidly reactivated on addition of Zn ions even at pH 4 to 6. However, zinc ions are unable to replace magnesium ions as cocatalysts for the enzymatic hydrolysis of organic phosphates by alkaline phosphatase.

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Identification of Functional Groups of Pig Kidney Alkaline Phosphatase by Specific Inhibitors

Zeitschrift für Naturforschung C ◽

10.1515/znc-1975-11-1226 ◽

1975 ◽

Vol 30 (11-12) ◽

pp. 829-831 ◽

Cited By ~ 2

Author(s):

Jan Ahlers

Keyword(s):

Alkaline Phosphatase ◽

Functional Groups ◽

Pig Kidney ◽

Kidney Alkaline Phosphatase ◽

Specific Inhibitors ◽

Regulatory Sites

Abstract Inactivation studies with 17 group-specific inhibitors showed that amino, hystidyl and tyrosyl residues probably are components of the active and/or regulatory sites of pig kidney alkaline phosphatase.

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Effects of Cadmium Exposure on Bone and Kidney Alkaline Phosphatase Activity and Acid Phosphatase Activity in Testis and Prostate Gland in the Male Rat

Journal of Applied Sciences and Environmental Management ◽

10.4314/jasem.v6i1.17186 ◽

2002 ◽

Vol 6 (1) ◽

Author(s):

F O OBI ◽

ILORI O. OLABODE

Keyword(s):

Alkaline Phosphatase ◽

Acid Phosphatase ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Acid Phosphatase Activity ◽

Prostate Gland ◽

Cadmium Exposure ◽

Male Rat ◽

Kidney Alkaline Phosphatase

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A kinetic study of rat kidney alkaline phosphatase

Archives of Biochemistry and Biophysics ◽

10.1016/0003-9861(67)90214-7 ◽

1967 ◽

Vol 122 (2) ◽

pp. 417-420 ◽

Cited By ~ 3

Author(s):

F. Melani ◽

M. Farnararo ◽

G. Sgaragli

Keyword(s):

Alkaline Phosphatase ◽

Kinetic Study ◽

Rat Kidney ◽

Kidney Alkaline Phosphatase

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Effects of Magnesium Ions on Thermal Inactivation of Alkaline Phosphatase

The Protein Journal ◽

10.1007/s10930-005-7643-x ◽

2005 ◽

Vol 24 (7-8) ◽

pp. 479-485

Author(s):

Ying Zhu ◽

Xue-Ying Song ◽

Wen-Hua Zhao ◽

Ying-Xia Zhang

Keyword(s):

Alkaline Phosphatase ◽

Thermal Inactivation ◽

Magnesium Ions

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Phosphoester specificity of purified human liver alkaline phosphatase

Canadian Journal of Biochemistry ◽

10.1139/o79-124 ◽

1979 ◽

Vol 57 (7) ◽

pp. 1000-1007 ◽

Cited By ~ 8

Author(s):

L. E. Seargeant ◽

R. A. Stinson

Keyword(s):

Alkaline Phosphatase ◽

Atpase Activity ◽

Human Liver ◽

Magnesium Ions ◽

Calcium Dependent ◽

Ph Values ◽

Regulator Protein ◽

Calcium And Magnesium ◽

Hydrolysis Of ◽

Calcium And Magnesium Ions

Kinetic parameters for the hydrolysis of a number of physiologically important phosphoesters by purified human liver alkaline phosphatase have been determined. The enzyme was studied at pH values of 7.0 to 10.0. The affinity of the enzyme for the compounds was determined by competition experiments and by their direct employment as substrates. Phosphodiesters and phosphonates were not hydrolysed but the latter were inhibitors. Calcium and magnesium ions inhibited the hydrolysis of ATP and PP1 and evidence is presented to show that the metal complexes of these substrates are not hydrolysed by alkaline phosphatase. A calcium-stimulated ATPase activity could not be demonstrated for the purified enzyme or the enzyme in the presence of a calcium-dependent regulator protein. Nevertheless, the influence of magnesium and calcium ions on the ATPase activity of alkaline phosphatase means that precautions must be taken when assaying for Ca2+-ATPase in the presence of alkaline phosphatase.The low substrate Km values and the hydrolysis which occurs at pH 7.4 mean that the enzyme could have a significant phosphohydrolytic role. However, liver cell phosphate concentrations, if accessible to the enzyme, are sufficient to strongly inhibit this activity.

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