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)

Adenophostins A (1, C16H26N5O18P3) and B (2, C18H28N5O19P3), potent agonists of inositol-1,4,5-triphosphate (InsP3) receptor, were isolated from the culture broths of Penicillium brevicompactum SANK 11991 and SANK 12177. Hydrolysis of 2 with aq NaOH gave 1. Oxidation of 2 with NaNO2 gave the hypoxanthine derivative (3). Treatment of 1 or 2 with alkaline phosphatase gave 4 and 5. Treatment of 4 with alpha-glucosidase gave adenosine. Thus, their structures were deduced to be adenosine nucleotides by NMR, MS and the enzymatic degradation. The inhibitory constants (Ki value) of 1, 2, 3 and InsP3 itself for binding to the InsP3 receptor were 0.18 nM, 0.18 nM, 0.29 nM and 15 nM, respectively.
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PMID:Adenophostins A and B: potent agonists of inositol-1,4,5-trisphosphate receptor produced by Penicillium brevicompactum. Structure elucidation. 811 67

Linear and branched glycopeptides containing multiple sialyl-N-acetyllactosamine side chains have been synthesized using a combined chemical and enzymatic approach. Peptide backbones in which beta-GlcNAc-Asn residues were incorporated were obtained in good yields by optimized solid-phase synthesis following the Boc strategy. The resulting multivalent glycopeptides were galactosylated in near-quantitative yields using bovine galactosyltransferase, UDP-galactose, and calf alkaline phosphatase that destroys the inhibiting side product UDP. Subsequent enzymatic sialylation yielded the desired glycopeptides containing asparagine-linked sialyl-N-acetyllactosamine side chains. The compounds were characterized by 1H NMR and FABMS. Recombinant sialyltransferase and CMP-sialate synthetase were used for the enzymatic synthesis of sialosides on a preparative scale. The synthetic glycopeptides were tested as inhibitors of influenza virus to cells, revealing that most of the multivalent sialoglycopeptides exhibit increased binding that depends on the spacing when compared to monovalent compounds. A possible mechanism for increased binding is proposed.
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PMID:Chemical and enzymatic synthesis of multivalent sialoglycopeptides. 814 76

The 5-methylthio-D-ribose moiety of 5'-(methylthio)-adenosine is converted to methionine in a wide variety of organisms. 2,3-Diketo-5-methylthio-1-phosphopentane is an advanced intermediate in the methionine recycling pathway present in the Gram-negative bacterium Klebsiella pneumoniae. This unusual metabolite is oxidatively cleaved to yield formate (from C-1), 2-keto-4-methylthiobutyrate (the transamination product of methionine), and 3-methylthiopropionate. To further characterize this oxidative conversion, the desthio analog of the naturally occurring diketone, namely 2,3-diketo-1-phosphohexane I, was synthesized. If the metabolism of I is analogous to that of 2,3-diketo-5-methylthio-1-phosphopentane it should be converted to formate, 2-ketopentanoate, and butyrate. An enzyme (E-1), which mediates the oxidative conversion of I to formate and 2-ketopentanoate, was isolated from extracts of K. pneumoniae. E-1 was purified 100-fold to homogeneity in 10% yield. The native enzyme is a monomeric protein of M(r) 27,000. The activity of E-1 requires magnesium ion as a cofactor. No other prosthetic groups were detected. Incubation of the enzyme with I, under anaerobic conditions, led to the discovery of two intermediates. These species have been identified by 1H and 13C NMR, UV-visible spectroscopy, and model chemistry studies as 2-hydroxy-3-keto-1-phospho-1-hexene II, generated by enolization of I; and 1,2-dihydroxy-3-keto-1-hexene III, generated by enzymatic dephosphorylation of II. Intermediates II and III are released from the active site of the enzyme; III accumulates under anaerobic conditions. Under aerobic conditions, III is non-enzymically oxidized to 2-ketopentanoate, formate, and other products. Compound II was also generated by heating I at pH 7.5 for 7 min. Action of alkaline phosphatase on II produces III.
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PMID:Purification and characterization of an enzyme involved in oxidative carbon-carbon bond cleavage reactions in the methionine salvage pathway of Klebsiella pneumoniae. 822 39

In vivo 31P NMR has been used to characterize the phosphorylated compounds present in the heart from vertebrate ectotherms. The perfused hearts from all animals experimented showed prominent resonances between the inorganic phosphate and phosphocreatine peaks. The pattern of these compounds was found to be different in the heart of the different species. As shown by 31P and proton NMR of perchloric extracts, the chemical shift of some of the compounds was characteristic of glycerophosphorylcholine, glycerophosphorylinositol, phosphorylcholine, phosphorylserine, phosphorylethanolamine and phosphoenolpyruvate. The non-identified resonances were found to be phosphodiesters, as demonstrated by alkaline phosphatase hydrolysis. The physiological significance of these high levels of phosphodiesters in the heart from vertebrate ectotherms is discussed.
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PMID:Detection of phosphodiester resonances in the perfused heart from vertebrate ectotherms with nuclear magnetic resonance. 825 Sep 49

Some aspects of the physiology of chondrocytes from horse articular cartilage were studied, since this animal model can be helpful in understanding arthritic processes. The replicative ability of articular chondrocytes, measured by the incorporation of [3H]thymidine, and their capacity of proteoglycan production, evaluated from the incorporation of [35S] sulfate, are very low. In addition, these cells do not differentiate in vitro as shown by the constant specific activity of alkaline phosphatase measured at different times in culture. Two types of potassium channels were identified by patch clamp experiments in the cell-attached configuration, one characterized by a conductance of 40 pS and the other of 100 pS. No active K+ channels were found at Vpip = 0. It was shown by Fura-2 experiments that the low replicative ability is paralleled by a modest variation of the intracellular calcium concentration after a mitogenic stimulus. 31P NMR experiments, both on slices of whole articular cartilage and on isolated cells, demonstrate that chondrocytes derive their energy mainly from the glycolytic pathway.
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PMID:Energy metabolism, replicative ability, intracellular calcium concentration, and ionic channels of horse articular chondrocytes. 826 89

An alkaline phosphatase assay was used to determine the dissociation constants (KD) of the lac repressor N-terminal 56 amino acid fragment of the wild type and of a Y7I mutant complexed to 22 base pair (bp) wild-type and mutant symmetrical operator sequences. KD's in 0.35 M monovalent salt ranged from 5.4 X 10(-8) M for the wild-type repressor.wild-type operator complex to approximately > 1 X 10(-6) M for the wild-type repressor.nonspecific DNA complex. Mutant operators O2 (G5 --> A5 and G16 --> T16) and O4 (G5 --> C5 and C16 --> G16) bind nearly as tightly as the wild-type headpiece, while mutant O3 (A8 --> T8 and T13 --> A13) binds over 5-fold poorer. Operators O1, O2, and O4 bind ca. 10-fold poorer to the Y7I mutant headpiece. Operator O3 binds 2-fold poorer to the mutant headpiece. The temperature and salt dependence on the dissociation constants of wild-type headpiece binding to 22-bp operator support the conclusion that the headpiece contains the major DNA recognition portion of the protein and that electrostatics plays as important a role in the binding of operator to headpiece as it does in the whole repressor. The 31P NMR spectra of shortened 14-bp wild-type and mutant symmetrical operators bound to the N-terminal 56-residue headpiece of the Y7I mutant repressor were compared to the spectra of the same operator bound to the wild-type repressor headpiece. These results are consistent with a recent proposal [Karslake, C., Botuyan, M. V., & Gorenstein, D. G. (1992) Biochemistry 31, 1849-1858] that specific, tight-binding operator.protein complexes retain the inherent phosphate ester conformational flexibility of the operator itself, whereas the phosphate esters are conformationally restricted in the weak-binding operator-protein complexes. This retention of backbone torsional freedom in tight complexes is entropically favorable and provides a mechanism for protein discrimination of different operator binding sites.
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PMID:31P nuclear magnetic resonance spectra and dissociation constants of lac repressor headpiece.duplex operator complexes: the importance of phosphate backbone flexibility in protein.DNA recognition. 833 19

Several lignans, mostly new, were isolated from Larrea tridentata by assay-guided counter-current chromatography (CCC). Using the secreted alkaline phosphatase bioassay of HIV Tat transactivation and the two-phase hexane-ethyl acetate-methanol-water solvent system, two major components (Gr and Lo) were identified as anti-HIV active principles. The chemical structures of the constituents of Gr (G1-G4) and Lo (L1-L4) were determined by GC-MS and NMR. After optimization of isolation conditions, a large-scale isolation with the chloroform-methanol-water system yielded five constituents (FB1-FB5). The most predominant anti-HIV compound FB2 (denoted Malachi 4:5-6 or mal.4), which occurs in 0.23% yield, was separated from its FB1 isomer (0.13% yield). Compound FB4 and two tricyclic lignans (FB3 and FB5) were also isolated in a substantial amount for further testing of their anti-HIV activities. These compounds may represent a new class of anti-HIV agents with important clinical relevance.
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PMID:Isolation of anti-HIV-1 lignans from Larrea tridentata by counter-current chromatography. 858 Nov 22

Seven synthetic polymers, (Glu4, Tyr)n, (Arg)n, (Arg, Pro, Thr)n, (Arg-Gly-Glu)6, (Arg-Gly-Phe)6, (Glu-Arg-Gly-Phe)5, and (Ala-Leu-Arg-Arg-Ile-Arg-Gly-Glu-Arg)2, were treated with phosphoryl chloride to phosphorylate their Tyr, Thr, and Arg residues. Protamines and histones were phosphorylated similarly. These phosphorylated peptides were examined as to whether or not they serve as substrates for intestinal alkaline phosphatase [EC 3.1.3.1] and liver N(omega)-phosphoarginine phosphatase [Kuba, M., Ohmori, H., and Kumon, A. (1992) Eur. J. Biochem. 208, 747-752]. Phosphorylated polyarginine was hydrolyzed with a lower Km with alkaline phosphatase than with N(omega)-phosphoarginine phosphatase, while the phosphorylated forms of (Arg-Gly-Phe)6 and culpeine were better substrates for N(omega)-phosphoarginine phosphatase. When (Arg, Pro, Thr)n and culpeine were phosphorylated chemically after treatment with phenylglyoxal, these phosphorylated peptides were worse substrates for N(omega)-phosphoarginine phosphatase than for alkaline phosphatase. Moreover, the results of proton-decoupled 31P NMR analysis indicated that N(omega)-phosphoarginine phosphatase released Pi from N(omega)-phosphoarginine residues of phosphopeptides. These results indicate that both phosphatases function as protein arginine phosphatases in different manners, and that N(omega)-phosphoarginine phosphatase is useful for selectively detecting N(omega)-phosphoarginine residue in peptides containing various kinds of phosphorylated amino acids.
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PMID:N(omega)-phosphoarginine phosphatase (17 kDa) and alkaline phosphatase as protein arginine phosphatases. 874 74

Renal papillary necrosis (RPN) was induced in Fischer 344 (F344) rats (n = 4) using 2-bromoethanamine hydrobromide (BEA) dosed at 150 mg/kg, and in multimammate desert mice (Mastomys natalensis) at 150 and 250 mg/kg (n = 4 per group). Control rats and Mastomys were dosed with 0.9% saline (n = 4 per group). Urine was collected at regular intervals for up to 4 days post-dosing and analysed for low MW metabolites using high resolution 1H NMR spectroscopy. The urinary activity of lactate dehydrogenase, gamma-glutamyl transpeptidase and alkaline phosphatase was determined using conventional biochemical assays. On termination, histopathological examination of papillae was performed showing the development of extensive lesions in F344 rats at 150 mg/kg BEA. Mastomys appeared much more resistant to BEA and showed normal renal histology at 150 mg/kg and patchy lesions at 250 mg/kg BEA. Enzyme analysis of control urine showed F344 rats to have > 1000% higher gamma-glutamyl transpeptidase activity than Mastomys. 1H NMR spectroscopic analysis showed that BEA caused a substantial decrease in urinary concentrations of succinate and citrate (0-24 h p.d.) and an increase in creatine (0-96 h p.d.) in both animal models. A decrease in the urinary concentration of 2-oxoglutarate with a subsequent increase by 72-96 h p.d. was also noted in both animal models. Glutaric and adipic aciduria were also induced in both F344 rats and Mastomys 0-24 h post-BEA treatment, indicative of an enzyme deficiency in the acyl CoA dehydrogenases. Urinary taurine levels were elevated in Mastomys following the administration of BEA, indicating some degree of liver toxicity. Urinary taurine was not elevated in F344 rats following BEA administration, demonstrating further species difference in BEA toxicity.
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PMID:Comparative studies on the nephrotoxicity of 2-bromoethanamine hydrobromide in the Fischer 344 rat and the multimammate desert mouse (Mastomys natalensis). 877 80

Nephrocalcin (NC), an acidic glycoprotein with molecular weight 14,000, is present in urine and prevents kidney stone formation. Histoimmunochemical staining shows that NC is localized in the proximal tubles in kidneys. Isolated NC from mammalian urine, revealed at least 4 isoforms of NC (we call these isoforms NC-A, NC-B, NC-C, and NC-D in the order of elution) during DEAE cellulose column chromatography with a linear gradient of NaCl elution step. Non-stone forming people excrete more NC-A and NC-B isoforms in urine; however, more NC-C and NC-D isoforms were found in stone formers' urine. When the organic matrix was extracted from surgically removed calcium oxalate kidney stones, we found greater quantities of NC-C and NC-D isoforms than those of NC-A and NC-B isoforms. Amino acid compositions and carbohydrate contents of these 4 isoforms were similar with the exception of the gamma-carboxyglutamic acid (GLA) residues. Only the NC-A and NC-B isoforms contained residues of GLA. There were more phosphate residues present in NC-C and NC-D than in NC-A and NC-B. Upon removal of phosphate residues by alkaline phosphatase, NC-C eluted at the same salt concentrations as NC-A eluted. This indicates that the backbone protein could be similar, but the NC-C isoform is modified by excess phosphate residues. Surface tension measurements using a Lauda film balance indicated that NC-A and -B were strongly amphiphilic while NC-C and -D were less amphiphilic. NC-A has an elongated shape, and occupies a smaller area per molecule; whereas NC-C is a bulky molecule. Using NC-A as a model of a "good" inhibitor and NC-C as a model of a "poor" inhibitor, both bound with 4 atoms of Ca2+ per molecule as investigated by equilibrium dialysis method, 31P-NMR, and electron spin resonance spectrometry. Isoforms A and B changed their conformation upon Ca2+ binding, but C and D did not change their conformation. All these observations suggest that isoforms A and B are strong inhibitors of calcium oxalate monohydrate (COM) crystal growth and aggregation. However, isoforms C and D act as promotors for COM crystal growth-kidney stone formation. Measuring the amount of NC in urine from renal cell carcinoma patients and from NC isolated from a supernatant of a primary renal cell carcinoma cells demonstrated the amount of NC increased with disease progression.
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PMID:Properties and function of nephrocalcin: mechanism of kidney stone inhibition or promotion. 909 76


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