Hormonal induction of alkaline phosphatase activity by an increase in catalytic efficiency of the enzyme

Cox, Rody P.; Elson, Norton A.; Tu, Shing Hui; Griffin, Michael K.

doi:10.1016/0022-2836(71)90241-5

Cited by 133 publications

(33 citation statements)

References 28 publications

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“…This finding demonstrated that the Zn2 of the induced alkaline phosphatase is less suited for chelation than that of the control enzyme. Therefore, there probably exists a difference in the binding of the Zn2i to the apoenzyme between the control and the induced enzyme [6]. Likewise our results showed an increase of the catalytic efficiency and a relative insensitivity to EDTA inactivation of the cord blood LAP.…”

Section: Discussionsupporting

confidence: 72%

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Characterization of Newborn Leukocyte Alkaline Phosphatase

A¹,

Coppa²,

Marcucci³

et al. 1973

Neonatology

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Leukocyte alkaline phosphatase (LAP) from cord blood was characterized by means of acrylamide gel disc electrophoresis, eneuraminidase sensitivity, heat inactivation, L-phenylalanine and L-homoargÍnine in hibition and EDTA inactivation. No differences were found between the LAP of cord blood and that of children in acrylamide gel disc electrophoresis, neuraminidase sensitivity, heat inactivation and L-homoarginine inhibition. Acrylamide gel disc electrophoresis of the agarose purified enzyme and EDTA inhibition studies suggest that the increase of LAP in cord blood depends on an increase of the catalytic efficiency of the enzyme.

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Section: Discussionsupporting

confidence: 72%

“…Recently, Cox el at. [6] found that the induced alkaline phosphatase is less susceptible to EDTA inactivation in comparison with the control enzyme. This finding demonstrated that the Zn2 of the induced alkaline phosphatase is less suited for chelation than that of the control enzyme.…”

Section: Discussionmentioning

confidence: 99%

Characterization of Newborn Leukocyte Alkaline Phosphatase

A¹,

Coppa²,

Marcucci³

et al. 1973

Neonatology

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“…Their involvement is postulated when the glucocorticoidinduced change in enzyme activity results from a change in the properties of enzyme molecules, as is the case for the inhibition of plasminogen activator (Coleman et al, 1982). Another example is induction of alkaline phosphatase, which has been ascribed, at least in part, to a glucocorticoidinduced dephosphorylation mechanism (Cox & Elson, 1971). Glucocorticoid-induced intermediates should also be suspected when the lag period (Rousseau et al, 1980), but becomes detectable long after induction of tyrosine aminotransferase, a transcriptional effect, has taken place (Fig.…”

Section: Glucocorticoids Modulate Mrna Concentrationmentioning

confidence: 99%

Control of gene expression by glucocorticoid hormones

Rousseau¹

1984

Biochemical Journal

142

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Glucocorticoids control the expression of a small number of transcriptionally active genes by increasing or decreasing mRNA concentration. Either effect can result from a transcriptional or a post-transcriptional mechanism. Induction of mouse mammary tumour virus RNA results from a stimulation of transcription initiation and depends on the presence of defined regions in proviral DNA. These regions bind the glucocorticoid receptor and behave functionally as proto-enhancers. Glucocorticoid-inducible genes can retain their sensitivity to the hormone after transfer to a heterologous cell by transfection techniques. Non-inducible genes can become inducible when linked to the promoter region of an inducible gene. The mechanisms by which the receptor-steroid complex stimulates or inhibits transcription or influences mRNA stability are unknown. Receptor binding to nucleic acids appears to be a necessary but not sufficient condition. It is likely that the receptor also interacts with chromatin proteins. This might lead to a catalytic modification of these proteins, resulting in a modulation of gene expression. Development of glucocorticoid-sensitive, biochemically defined, cell-free transcription systems should provide a tool to delineate the molecular determinants of this essential regulatory mechanism.

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“…30 Sprague-Dawley rats were sacrificed, and the intestinal mucosa was removed by scraping. Brush borders were prepared by the method of Forstner et al (19) and added to sufficient 0.05 M potassium phosphate buffer, pH 7.2, to yield a protein concentration of 4 mg/ml.…”

Section: Introductionmentioning

confidence: 99%

The Intestinal Brush Border Membrane in Diabetes

Olsen¹,

Korsmo²

1977

J. Clin. Invest.

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A B S T R A C T Diabetes stimulates the functional activity of the intestinal brush border membrane with enhancement of both hydrolytic enzyme activity and membrane transport systems. To determine the mechanism of this effect, we studied the effects of streptozotocin diabetes on the metabolism of one membrane protein, sucrase-isomaltase, which increases its activity in diabetes. The protein was purified and an antiserum prepared. Sucrase-isomaltase from control and diabetic rats was immunologically identical as shown by Ouchterlony double-diffusion analysis of papainsolubilized mucosal proteins. The increase in sucrase enzyme activity in diabetic animals (31.0±1.4 U SEM 5 days after streptozotocin vs. 13.1±1.0 in controls) was the consequence of increased enzyme protein and not an alteration in catalytic efficiency as demonstrated by quantitative immunoprecipitin reactions.To account for increased sucrase-isomaltase protein in diabetes we studied papain-solubilized mucosal proteins labeled by injection of [14C]carbonate and[14C]leucine and analyzed incorporation into sucraseisomaltase protein (anti-serum precipitable) and total protein (trichloroacetic acid precipitable). We found that diabetes did not affect the decay of labeled total protein, but prolonged the decay of labeled sucraseisomaltase. t4 of sucrase-isomaltase was 4.4 h in control animals after [14C]carbonate injection and 8.8 and 10.2 h, respectively, 2 and 5 days after induction of streptozotocin diabetes. We obtained similar results in experiments with [14C]leucine with diabetes increasing t4 from 6 to 13.6 h. Diabetes did not appear to increase the rate of addition of sucrase-isomaltase to the brush border membrane, since it did not affect the 10-and 60-min incorporations of isotope into sucraseReceived for publication 11 January 1977 and in revised form 16 March 1977. isomaltase protein relative to incorporation into total protein and did not alter rate constants for synthesis calculated from the ti and the change in enzyme mass over time.Thus, enhanced sucrase activity in the diabetic animal is the consequence of an increase in sucraseisomaltase protein which develops because of a decrease in its rate of degradation. INTRODUCTIONInsulin deficiency stimulates the functional activity of the brush border membrane of the intestinal absorptive cell. For example, experimental diabetes has been reported to increase the enzymatic activity of many brush border hydrolases including the disaccharidases (1-4) and to stimulate a number of transport systems believed to reside in this membrane (5-10). Diabetes mellitus in man has also been associated with increased intestinal disaccharidase activity (11, 12) and enhanced glucose absorption (13), although negative studies in man have also been reported (14, 15) perhaps because of differing severity of the disease and effects of treatrnent. We have examined the effects of experimental diabetes on the metabolism of a representative brush border membrane enzyme, sucrase, to obtain some insight into the mechani...

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Hormonal induction of alkaline phosphatase activity by an increase in catalytic efficiency of the enzyme

Cited by 133 publications

References 28 publications

Characterization of Newborn Leukocyte Alkaline Phosphatase

Characterization of Newborn Leukocyte Alkaline Phosphatase

Control of gene expression by glucocorticoid hormones

The Intestinal Brush Border Membrane in Diabetes

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