Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-Acetoxy-4-trifluoroacetylaminobiphenyl (N-acetoxy-TFAABP) reacted readily with Guo and GMP at neutrality in a one-step fashion to yield N-(guanosin-8-yl)4-aminobiphenyl (Guo-ABP) (I) and N(guanosin-8-yl)-4-aminobiphenyl-5'-monophosphate (GMP-ABP) (II), respectively. GMP-ABP could also be formed in much lower yield from the reaction of N-acetoxy-4-formylaminobiphenyl (N-acetoxy-FABP) with GMP (pH 7.0) under more rigorous conditions. Enzymatic hydrolysis of GMP-ABP with alkaline phosphatase in Tris buffer (pH 8.0) at 37 degrees C yielded Guo-ABP. Guo-ABP showed a brilliant blue fluorescence on exposure to 366 nm UV light and its UV absorption spectrum was identical to that of Guo-ABP prepared by Kriek via a different route. Elemental analysis and nuclear magnetic resonance (NMR) data further confirmed the identity of this compound.
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PMID:New syntheses of N-(guanosin-8-yl)-4-aminobiphenyl and its 5'-monophosphate. 625 8

Guinea pig epidermal DNAase I was purified from an epidermal extract by a procedure including DEAE-cellulose chromatography, Sephadex G-100 gel filtration and Con A-Sepharose affinity chromatography. The purified enzyme contained no detectable activities of acid DNAase, alkaline RNAase, phosphodiesterase or acid or alkaline phosphatase, but was contaminated with acid RNAase activity. The molecular weight of the enzyme was estimated to be 33 000 by sucrose density gradient centrifugation and Sephadex G-100 gel filtration. Its isoelectric point is 5.2 +/- 0.1. The enzyme requires divalent cations and exhibits two pH optima that are dependent on divalent cations: in the presence of Mn2+, the optimum pH is about 7.5 in 50 mM Tris-HCl buffer and in the presence of Mn2+, the pH is 6.4 in 50 mM cacodylate-HCl buffer. The enzyme hydrolyzes native DNA about 6-times faster than denatured DNA, producing 5'-phosphoryl and 3'-hydroxyl terminated oligonucleotides with an average chain length of about eight nucleotides, and converts double-stranded and circular DNA to relaxed and linear forms. The enzyme is inhibited by G-actin and antiserum against bovine pancreatic DNAase A. Thus this enzyme is classified as DNAase I.
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PMID:Purification and properties of a neutral endodeoxyribonuclease from guinea pig epidermis. 627 8

A trypsin-modified form of Escherichia coli alkaline phosphatase has been isolated, purified, and characterized. The native enzyme, previously thought to be resistant to proteases, shows a loss of 20% of its activity after a 30-min exposure to 10% trypsin. No further loss is seen after 3 h; this is in contrast to the apoenzyme which loses essentially all restorable activity (addition of saturating Zn(II) and Mg(II) restores activity to the apoenzyme) when exposed to trypsin. Under these conditions, a single major peptide is produced, cleaved at the Arg-10 Ala-11 bond, which is purified using a chromatographic technique that separates proteins according to their pI (chromatofocusing). This modified alkaline phosphatase has a Vmax of 2000 mumol/h/mg (1 M Tris, pH 8.0, 20 degrees C, 1 mM p-nitrophenolphosphate) which is 22% less than the Vmax for the native enzyme. The Km for p-nitrophenolphosphate is lower for trypsin-modified alkaline phosphatase than for the native enzyme, 1.9 X 10(-5) and 4 X 10(-5) M, respectively. The KI for Pi for the native enzyme is 1.5 X 10(-5) M and for trypsin-modified alkaline phosphatase is 1 X 10(-5) M, suggesting that the reduction in Vmax is due to a reduction in the rate constant for Pi dissociation. Differential scanning calorimetry results indicate differences in the stabilities of the two species. The trypsin-modified alkaline phosphatase has a Tm of 90 degrees C which is lower than that for the reconstituted apoenzyme (93.5 degrees C) or for the native enzyme (98.5 degrees C). This modified form of alkaline phosphatase may prove to be valuable in studies concerning subunit interactions in this system as the deleted decapeptide occurs at the subunit interface region in the native structure.
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PMID:Trypsin modification of Escherichia coli alkaline phosphatase. 636 7

Boar sperm plasma membranes were purified by differential and sucrose density equilibrium centrifugation and were found to yield a single band at a density of 1.14 g/cm3. Both alkaline and acid phosphatase activities were enriched in this fraction. The alkaline phosphatase activity was optimal in 100 mM tris (hydroxymethyl) methylamine (Tris)-NaHCO3 at pH 9.9 with 0.05% Triton X-100 and 1 mM MgCl2. This activity was inhibited by ethylenediaminetetraacetic acid (EDTA), cadmium, zinc or heating at 60 degrees C for 30 min. Also, L-homoarginine caused approximately 70% inhibition and L-phenylalanine or L-leucine caused about 10 to 20% inhibition. Acid phosphatase activity was optimal in 100 mM sodium acetate at pH 5.1 with 0.05% Triton. Sodium dodecyl sulfate, potassium fluoride (KF) or sulfhydryl reagents inhibited the activity, while EDTA or heating at 60 degrees C had no effect. These data for enzymes from boar sperm plasma membranes can be used for future work on the quantitation of the enzymes, distinguishing these two phosphatases from other phosphohydrolases, purification of the enzymes and for comparison to phosphatases in other tissues.
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PMID:Some properties of acid and alkaline phosphates from boar sperm plasma membranes. 650 37

3-Oxo-5 alpha-steroid: NAD+ delta 4-oxidoreductase ("NADH-5 alpha-reductase", EC 1.3.1.?) is rapidly inactivated in the presence of 17 beta-hydroxy-4-androsten-3-one (testosterone). This activation is prevented by increasing the phosphate concentration. When the enzyme assay is carried out in Tris-HCl, only a small activity (1.7 nmol X min-1 X mg-1) is observed which may be further decreased by addition of phosphatases. Addition of the phosphatase inhibitor dextran sulphate or ATP, Mg++ and c-AMP results in a significant increase of activity (228% and 273%, respectively) compared with the Tris-HCl control. Glycerol 2-phosphate and glycerol 3-phosphate have a stabilizing effect on 3-oxo-5 alpha-steroid: NAD+ delta 4-oxidoreductase by decreasing the Km towards the substrate testosterone from 1.2 X 10(-5) mol/l to 3.3 X 10(-6) mol/l. V remains unchanged. Half maximal velocity (testosterone reduction) is achieved with 20 mumol/l glycerol 2-phosphate and glycerol 3-phosphate. Addition of c-AMP dependent protein kinase (EC 2.7.1.37) to a microsomal preparation pretreated with alkaline phosphatase (EC 3.1.3.1) results in a significant increase of 3-oxo-5 alpha-steroid: NAD+ delta 4-oxidoreductase activity compared with the control.
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PMID:Rat liver 3-oxo-5 alpha-steroid delta 4-dehydrogenase. Modulation of enzyme activity by changes in phosphorylation state. 652 91

Granulocyte alkaline phosphatase (GAP) was extracted from the leukocyte suspensions of 15 subjects with chronic myeloid leukemia (CML), determining the Zn content by atomic absorption spectrophotometry. The purified enzymatic preparation was dialyzed against a ZnCl2 solution (.01 mg%) in TRIS-HCl 0.1 M, pH 7.5, for 48 hours. After dialysis Zn concentration and GAP activity reached normal values. This suggests that the GAP molecule isolated from CML subjects is not altered as it is able to receive at most 2 Zn moles responsible for the enzymatic function.
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PMID:Alkaline phosphatase activity improved by the addition of zinc in granulocytes from leukemic subjects (in vitro study). 659 61

Rat liver spermidine/spermine N1-acetyltransferase was found to be strongly inhibited by the dyes Cibacron F3GA, Coomassie Brilliant Blue and Congo Red. Inhibition was competitive with respect to acetyl-CoA and Ki values of 0.7 microM and 52 microM were determined for Cibacron F3GA and Coomassie Brilliant Blue respectively. The enzyme was strongly retained by columns of Affi-Gel Blue, which contains Cibacron F3GA linked to agarose. It was not eluted from this adsorbent in the presence of 10 mM-spermidine/0.5 M-NaCl/50 mM-Tris/HCl, pH 7.5, but was released by 1 mM-CoA in 10 mM-spermidine/50 mM-Tris/HCl, pH 7.5. These results are consistent with the presence in the enzyme of a dinucleotide fold that binds acetyl CoA and has a high affinity for Cibacron F3GA. The spermidine/spermine N1-acetyltransferase was irreversibly inactivated by exposure to butane-2,3-dione in sodium borate, pH 7.8, or by exposure to phenylglyoxal or camphorquinone-10-sulphonic acid. All of these reagents are known to interact with arginine residues in proteins under the conditions in which they inactivated the acetyltransferase. Inactivation was prevented by the presence of acetyl-CoA or CoA, but to a lesser extent by 3'-dephospho-CoA and not at all by NAD or adenosine. This protection suggests that an arginine residue at the active site is involved in the binding of the acetyl-CoA substrate. Treatment of the assay mixture but not the spermidine N1-acetyltransferase with alkaline phosphatase prevented the reaction taking place. This suggests that the apparent loss of enzyme activity in response to alkaline phosphatase reported by Matsui, Otani, Kamei & Morisawa [(1982) FEBS Lett. 150, 211-213] is due to dephosphorylation of the acetyl-CoA substrate and that the 3'-phosphate group is essential for activity.
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PMID:Studies of the acetyl-CoA-binding site of rat liver spermidine/spermine N1-acetyltransferase. 661 55

The ultrastructural localization and gradient of activity of alkaline phosphatase were studied with respect to cell differentiation, matrix synthesis, and matrix mineralization in the incisor and molar teeth of 4-day-old Sprague-Dawley rats. The animals were perfused intracardially at room temperature with 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4) with 3-4% sucrose. The jaws were dissected, immersion-fixed for 24 h, and the incisor and molar tooth germs removed. These were determined in 10% EDTA in NaOH (pH 7.4) with 7% sucrose. After reactivation of the enzyme with 0.1M MgCl in Tris-maleate buffer (pH 7.4) at 4 degrees C, the medium consisting of 6 ml 3% sodium beta-glycerophosphate, 4 ml 0.2M Tris-HCl buffer (pH 9.2), 3 ml 1.6% MgSO4, 12 ml 0.5% lead citrate (pH congruent to 12), and 2.1 g sucrose. The pH was adjusted to 9.2 with 0.2M HCl, the volume made up to 30 ml, and the solution centrifuged for 10 min at 5000 rpm. Control teeth were incubated in medium minus the substrate. Finally, the specimens were routinely post-fixed and embedded for sectioning and examination with a Philips 300 electron microscopy. A gradient of alkaline phosphatase activity was mapped along the developing teeth in the cells of the stratum intermedium, the proximal borders of the ameloblasts, the early dentine matrix, the predentine-dentine border, matrix vesicles, and the plasma membranes of odontoblasts and subodontoblast cells. The gradient of alkaline phosphatase activity was evident in the forming tooth from the cervical loop to the crown apex and was related to the cellular events, matrix synthesis, and matrix mineralization occurring during odontogenesis.
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PMID:Ultrastructural localization and gradient of activity of alkaline phosphatase activity during rodent odontogenesis. 680 89

Chicken skeletal alkaline phosphatase is subject to competitive inhibitions by vanadate (Ki = 0.38 mM in carbonate, Ki = 0.08 mM in Tris, both at pH 7.4) and phenylphosphonate (Ki = 15 mM in carbonate, Ki = 1.3 mM in Tris, both at pH 7.4), and uncompetitive inhibition by levamisole (Ki = 0.08 mM in carbonate, Ki = 0.10 mM in Tris, both at pH 7.4). The competitive inhibitors were more effective in Tris buffer because nonreactive ternary complexes were formed between alkaline phosphatase, the inhibitor and Tris. The effects of vanadate, phenylphosphonate and levamisole on the proliferation of embryonic chick calvarial cells in vitro were biphasic. Low doses of each agent stimulated 3H-thymidine incorporation into TCA-insoluble material; higher doses were inhibitory. Neither effect could be attributed to inhibition of alkaline phosphatase activity (e.g. 20 microM vanadate should inhibit alkaline phosphatase by 3% but stimulated cell proliferation by 187%; 50 microM vanadate should inhibit alkaline phosphatase by 7% but inhibited 3H-thymidine incorporation by 90%). None of the alkaline phosphatase inhibitors tested affected the cellular concentration of the enzyme during the 24-hour incubation. These studies indicate that alkaline phosphatase inhibitors can have nonspecific effects on bone cells in culture, and that for cells in the osteoblast cell line, an inhibition of alkaline phosphatase activity is not consistently related to a decrease in cell proliferation.
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PMID:Effect of skeletal alkaline phosphatase inhibitors on bone cell proliferation in vitro. 692 63

Normal thymocyte and bone marrow terminal deoxynucleotidyl transferase (TdT) have distinguishing characteristics by phosphocellulose chromatography in Tris buffer: marrow TdT elutes as a single peak at 0.3 M salt, whereas thymocyte TdT separates into two forms, one at 0.3 M salt and one at 0.4 M salt. Since the majority of TdT-positive acute leukemias are anatomically bone marrow-derived, one would have predicted the presence of a bone marrow TdT-phosphocellulose chromatographic pattern in such patients. However, in 376 consecutive, untreated TdT-positive acute lymphoblastic leukemias (ALL) studied by us we have invariably encountered the two-peak thymocyte-type phosphocellulose pattern. The TdT patterns in the thymic-dependent, TdT-positive lymphoma of AKR mice, and the TdT-positive bone marrow-derived, thymic-independent Abelson virus leukemia of Balb/C mice duplicate the situation in human ALL: a thymocyte pattern is seen in both the marrow-derived and thymus-derived diseases. This chromatographic difference between leukemia-associated and normal marrow-associated TdT in both murine and human leukemia suggested that phosphocellulose-TdT patterns might be useful for monitoring residual marrow tumour cell burden in TdT-positive leukemia. This has not turned out to be the case: in eight patients studied in early relapse the blast cell TdT pattern was the single-peak 0.3 M species. Therefore, leukemic cell TdT cannot reliably be distinguished from normal marrow cell TdT. The chromatographic behaviour of TdT may be regulated by phosphorylation-dephosphorylation, the 0.3 M salt peak can be converted to the 0.4 M salt species by treatment with protein kinase and ATP, and the 0.4 M species can be converted to the 0.3 M form by exposure to alkaline phosphatase. Thus, apparently anatomic compartment-specific forms of TdT may only reflect differing cellular metabolic activity.
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PMID:Chromatographic forms of terminal deoxynucleotidyl transferase in normal lymphoid cells and in leukemia cells at presentation and relapse. 698 13


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