Kinetics of the Escherichia coli alkaline phosphatase catalyzed hydrolysis of 2,4-dinitrophenyl phosphate

1967 ◽  
Vol 89 (26) ◽  
pp. 7139-7140 ◽  
Author(s):  
Sai-Hang D. Ko ◽  
Ferenc J. Kezdy
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Kinetics Of ◽  
Hydrolysis Of

scholarly journals Chicken Intestinal Alkaline Phosphatase

1960 ◽  
Vol 43 (6) ◽  
pp. 1149-1169 ◽  
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.

THE ROLE OF ALKALINE PHOSPHATASE IN INTESTINAL ABSORPTION I. THE KINETICS OF PHOSPHATASE ACTION ON VARIOUS SUBSTRATES

1953 ◽  
Vol 31 (1) ◽  
pp. 1-7
Author(s):  
Neil B. Madsen ◽  
Jules Tuba
Keyword(s):  
Alkaline Phosphatase ◽  
Average Energy ◽  
Inorganic Phosphorus ◽  
Intestinal Alkaline Phosphatase ◽  
Egg Lecithin ◽  
Michaelis Constants ◽  
Inhibition Studies ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of intestinal alkaline phosphatase action on sodium β-glycerophosphate, glucose 6-phosphate, and egg lecithin have been studied and compared. The Michaelis constants indicate that the enzyme shows considerably less affinity for lecithin than for the other two substrates, and the approximate ratio of activity with lecithin, glucose 6-phosphate, and sodium β-glycerophosphate is 11 : 78.5 : 100. The energies of activation for the hydrolysis of the three substrates do not differ appreciably and the average energy of activation is 14,500 calories per gram-mole. The similarity of the energies of activation together with results from inhibition studies indicate that in all probability the same enzyme is responsible for the release of inorganic phosphorus from each of the three substrates.

scholarly journals The kinetics of hydrolysis of synthetic glucuronic esters and glucuronic ethers by bovine liver and Escherichia coli β-glucuronidase

1973 ◽  
Vol 133 (4) ◽  
pp. 789-795 ◽  
Author(s):  
J. Tomašić ◽  
D. Keglević
Keyword(s):  
Escherichia Coli ◽  
Kinetic Data ◽  
Glucuronic Acid ◽  
Bovine Liver ◽  
Kinetics Of Hydrolysis ◽  
Substrate Saturation ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Ylacetic Acid ◽  
Optimal Ph

1. The relative rates of hydrolysis of synthetically prepared β-d-glucuronic esters [aglycone: benzoic acid, veratroic (3,4-dimethoxybenzoic) acid, indol-3-ylacetic acid and ethylbutyric acid], and β-d-glucuronic ethers (aglycone: phenolphthalein, p-nitrophenol, 3,4-dimethoxyphenol, 3,4-dimethoxybenzyl alcohol) by commercial preparations of β-glucuronidase from bovine liver and Escherichia coli were investigated. The rates of hydrolysis of all compounds tested were followed by measuring the formation of glucuronic acid under conditions which do not affect the glycosidic ester bond. 2. The pH profiles of the substrates in reaction with the enzyme from both sources were determined, and substrate-saturation curves at the optimal pH for each substrate were constructed; double-reciprocal plots of activity against concentration were linear. 3. Comparison of kinetic data indicates that neither the type of sugar–aglycone linkage, nor the aglycone structure alone can explain the observed Km and Vmax. values. 4. α-d-Glucuronic esters of benzoic and veratroic acid resisted hydrolysis by β-glucuronidase from both sources.

scholarly journals Studies on alkaline phosphatase. Transientstate and steady-state kinetics of Escherichia coli alkaline phosphatase

1969 ◽  
Vol 111 (2) ◽  
pp. 187-194 ◽  
Author(s):  
H N Fernley ◽  
P. G. Walker
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Steady State ◽  
Substrate Concentration ◽  
Marked Effect ◽  
Binding Constants ◽  
Transient State ◽  
Steady State Kinetics ◽  
Ph Range ◽  
Kinetics Of

1. The transient-state and steady-state phases of the reaction between Escherichia coli alkaline phosphatase and 4-methylumbelliferyl phosphate were investigated by using a fluorimetric stopped-flow technique. 2. At low substrate concentration (5μm) in the pH range 3·8–6·3 there was an initial rapid liberation of up to 1mole of 4-methylumbelliferone/mole of enzyme. 3. At very low substrate concentration (0·1μm) in the pH range 4·9–5·9 an initial lag in 4-methylumbelliferone production was observed, from which values for k+1 and k−1 could be obtained. 4. The pH profiles for the rates of phosphorylation and dephosphorylation are quite different, and it is postulated that an ionizing group which determines the conformation during the phosphorylation step is not involved in the dephosphorylation step. 5. The binding constants for substrate and Pi are similar throughout the pH range 4–8. The ionization of substrate or Pi appeared to have no marked effect on the binding.

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