Phosphotransferase activity of human alkaline phosphatases and the role of enzyme Zn2+

Stinson, Robert A.; McPhee, Jennifer L.; Collier, H. B.

doi:10.1016/0167-4838(87)90135-x

Cited by 22 publications

(16 citation statements)

References 19 publications

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“…Fig. 2 shows that the re-calcification of demineralized bone in serum is dose-dependently inhibited by 1,10-phenanthroline, a zinc chelator that irreversibly inactivates alkaline phosphatase (24), with no evidence of Alizarin red staining or calcium and phosphate incorporation at the 1 and 3 mM doses of the inhibitor. Fig.…”

Section: Dose-dependent Effects Of Alkaline Phosphatase Inhibitors Onmentioning

confidence: 99%

“…Experiments with TNAP-deficient Serum in DMEM-Serum deficient in alkaline phosphatase activity was prepared using 1,10-phenanthroline, a zinc chelator that irreversibly inactivates the enzyme (24). In a typical experiment, 150 l of 1 M phenanthroline in methanol was combined with 10 ml of newborn calf serum in a 15-ml conical tube, and the tube was loosely capped and placed for 72 h in a humidified incubator at 37°C and 7.5% CO 2 .…”

Section: Methodsmentioning

confidence: 99%

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Tissue-nonspecific Alkaline Phosphatase Is Required for the Calcification of Collagen in Serum

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Toroian

Chan

2009

Journal of Biological Chemistry

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Previous studies have shown that the type I collagen of tendon and demineralized bone both calcify rapidly in serum. The speed, collagen matrix-type specificity, and extent of the re-calcification of demineralized bone in serum suggest that the serum calcification activity identified in these studies may participate in normal biomineralization. Because of its presence in serum and its long history of association with the normal mineralization of the collagen matrix of bone, tissue-nonspecific alkaline phosphatase (TNAP) is an obvious candidate for a protein that could be a component of serum calcification activity, and experiments were therefore carried out to test this possibility. These experiments show that the inactivation of TNAP in serum prevents collagen calcification, and that the addition of physiological levels of purified TNAP restores the ability of TNAP-deficient serum to calcify collagen. Additional experiments show that the role of TNAP in collagen calcification is to activate a serum nucleator of apatite crystal formation. Based on these and earlier studies, the mechanism of collagen calcification in serum requires at least four elements as follows. Our goal is to understand the biochemical mechanism responsible for the calcification of collagen fibrils in normal bone formation. In the course of our investigations, we have discovered that purified type I collagen and demineralized bone matrix both calcify rapidly when incubated in serum in the absence of cells (1-4). The calcification of collagen is because of the presence of a serum calcification activity, one sufficiently potent that collagen calcifies when incubated in media containing as little as 1.5% serum but not in serum-free media alone (1-4). This serum calcification activity consists of one or more proteins that are 50 -150 kDa in size (3, 4).Although serum-driven collagen calcification is an in vitro, cell-free assay, there are several reasons to believe that it could be relevant to understanding mechanisms by which collagen fibrils are mineralized in nature. 1) The assay conditions are physiologically relevant; collagen added to serum calcifies when incubated at the temperature and pH of mammalian blood, without the need to add anything to serum to promote mineralization, such as ␤-glycerophosphate or phosphate (see Ref. 1 and references therein). 2) Serum is relevant to bone mineralization; osteoblasts form bone in a vascular compartment (5), and proteins in serum have direct access to the site of collagen fibril formation and mineralization, whereas proteins secreted by the osteoblast appear rapidly in serum. 3) Serum-driven calcification is evolutionarily conserved; the serum calcification activity appeared in animals at the time vertebrates acquired the ability to form calcium phosphate mineral structures, with no evidence for a similar activity in the serum of invertebrates (2). 4) Serum-driven calcification is specific; calcification is restricted to those structures that were calcified in bone prior to demineralization, with n...

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Section: Dose-dependent Effects Of Alkaline Phosphatase Inhibitors Onmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Tissue-nonspecific Alkaline Phosphatase Is Required for the Calcification of Collagen in Serum

Price

Toroian

Chan

2009

Journal of Biological Chemistry

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“…Alkaline phosphatase (ortho-phosphoric-monoester phospho-hydrolase) removes phosphate-containing groups from many different molecules 2. Human ALP also has phospho-transferase3 and protein-phosphatase activity4 in vitro.…”

Section: Introductionmentioning

confidence: 99%

How to use… alkaline phosphatase in neonatology

Tinnion¹,

Embleton

2012

Arch Dis Child Educ Pract Ed

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Alkaline phosphatase (ALP) is regularly measured in clinical practice. Changes in serum levels are observed in a number of clinical conditions. In neonatology, it has been proposed as a useful marker for both a diagnosis and an indication of the severity of metabolic bone disease (MBD) in infants born preterm. Nutritional practices, aimed at reducing the occurrence or severity of MBD, have led to ALP being proposed as a stand-alone means of monitoring treatment. The current evidence does not support this use: ALP only achieves usefulness in a diagnostic and monitoring capacity when combined with other serum and imaging techniques.

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“…Stinson reported that 2-(ethylamino)ethanol increased BIALP probably by acting as a phophoacceptor [18]. Today, diethanolamine is commonly used as a dilution buffer of BIALP [19,20]. However, the activation mechanism of these substances has not been well elucidated.…”

Section: Introductionmentioning

confidence: 99%

Effects of amines and aminoalcohols on bovine intestine alkaline phosphatase activity

Sekiguchi

Hashida

Yasukawa

et al. 2011

Enzyme and Microbial Technology

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Bovine intestine alkaline phosphatase (BIALP) is widely used as a signaling enzyme in sensitive assays such as enzyme immunoassay (EIA). In this study, we evaluated the effects of various aminoalcohols and amines on the activity of BIALP in the hydrolysis of p-nitrophenyl phosphate (pNPP) at pH 9.8, at 20 °C. The k(cat) values at 0.05 M diethanolamine, 0.1 M triethanolamine, and 0.2 M N-methylethanolamine were 190±10, 840±30, and 500±10 s(-1), respectively. The k(cat) values increased with increasing concentrations of diethanolamine, triethanolamine, and N-methylethanolamine and reached 1240±60, 1450±30, and 2250±80 s(-1), respectively, at 1.0M. On the other hand, the k(cat) values at 0.05-1.0M ethanolamine, ethylamine, methylamine, and dimethylamine were in the range of 100-600 s(-1). These results indicate that diethanolamine, triethanolamine and N-methylethanolamine highly activate BIALP and might be suitable as a dilution buffer of BIALP in EIA. Interestingly, the K(m) values increased with increasing concentrations of diethanolamine and N-methylethanolamine, but not triethanolamine: the K(m) value at 1.0M diethanolamine (0.83±0.15 mM) was 12-fold higher than that at 0.05M (0.07±0.01 mM), and that at 1.0M N-methylethanolamine (2.53±0.20 mM) was 14-fold higher than that at 0.2M (0.18±0.02 mM), while that at 1.0M triethanolamine (0.31±0.01 mM) was similar as that at 0.2M (0.25±0.01 mM), suggesting that the mechanisms of BIALP activation are different between the aminoalcohols.

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Phosphotransferase activity of human alkaline phosphatases and the role of enzyme Zn2+

Cited by 22 publications

References 19 publications

Tissue-nonspecific Alkaline Phosphatase Is Required for the Calcification of Collagen in Serum

Tissue-nonspecific Alkaline Phosphatase Is Required for the Calcification of Collagen in Serum

How to use… alkaline phosphatase in neonatology

Effects of amines and aminoalcohols on bovine intestine alkaline phosphatase activity

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