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)

The sequence of tRNAGCCGly from human placenta was determined by recently developed postlabeling techniques. The tRNA was digested completely with RNases T1 and A in the presence of alkaline phosphatase, the oligonucleotides were 3'-terminally (3H)-labeled, mapped on PEI-cellulose thin layers, isolated, and sequenced by methods based on base-specific cleavages. Overlaps were obtained by readout sequencing techniques on polyacrylamide gels and PEI-cellulose thin layers. The thin-layer readout technique was used also to locate and identify modified nucleotides. The primary structure was found to exhibit a large degree of homology (94.6%) with silkworm tRNAGCCGly but only 67.6% homology with human tRNACCCGly.
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PMID:The nucleotide sequence of human tRNAGly (anticodon GCC). 11 97

Two dimensional PEI-cellulose thin layer chromatography can resolve sequentially degraded oligonucleotide fragments of tRNA. This technique entails the sequential degradation of the oligonucleotide with snake venom phosphodiesterase in the presence of bacterial alkaline phosphatase, and periodate oxidation followed by tritiated sodium borohydride reduction of the 3' terminal nucleoside. Subsequently the tritiated oligonucleotide fragments were resolved by two dimensional PEI-cellulose TLC. The results of these experiments indicate that, in some cases, the complete nucleotide sequence of a large oligonucleotide fragment may be determined by interpretation of the observed mobility shifts, thereby eliminiating the need for additional analysis of the oligonucleotide. In addition, the use of two-dimensional rather than one-dimensional resolution of the tritium labeled fragments allows for a complete separation of any interfering background spots from the sequentially degraded oligonucleotides. This procedure was applied to the complete nucleotide sequence analysis of several ribonuclease T1Val and ribonuclease A digestion products from human placenta tRNA.
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PMID:A two-dimensional thin layer chromatographic procedure for the sequential analysis of oligonucleotides employing tritium post-labeling. 41 70

Extracts of interferon-treated HeLa cells adsorbed to poly(I) . poly(C)-agarose have been used to synthesize 2'5'oligo(A). This oligonucleotide has been characterized by enzymatic digestion with alkaline phosphatase, snake venom phosphodiesterase, T2 ribonuclease and chromatography on DEAE, and PEI-cellulose. The oligonucleotide inhibits protein synthesis in vitro and activates an endonuclease present in extracts of control and interferon-treated cells. The metabolic stability of 2'5'oligo(A) has been investigated in these cell extracts. The oligonucleotide undergoes rapid degradation, particularly in the absence of ATP and of an energy regenerating system. Furthermore, the 2'5'oligo(A)-activated endonuclease reverts to an inactive state under these conditions, but can be reactivated upon further addition of 2'5'oligo(A). A possible role for the degradation of 2'5'oligo(A) in the mechanism of interferon action is discussed.
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PMID:Metabolic stability of 2' 5'oligo (A) and activity of 2' 5'oligo (A)-dependent endonuclease in extracts of interferon-treated and control HeLa cells. 42 14

Fifty eight patients with thyrotoxicosis were examined as well as 9 patients with hypothyroidism and 40 healthy subjects. A tendence towards hypercalcemia and hyperphosphatemia, hypercalciuria, hyperhydroxiprolinuria, elevated alkaline phosphatase were found in hyperthyroidism. In hypothyroidism--hypocalcemia, hypocalciuria, hypohydroxiprolinuria. The changes are associated with the direct effect of thyroid hormones upon bone system (intensified bone metabolism with predominance of destruction). Calciuria and HOP-uria in thyrotoxicosis depend on the severity of the disease. The elevated calcium excretion in thyrotoxicosis speaks for the presence of ostemalacic component. TRP, PEI, mean diametrically opposite in hyper- and hypothyroidism, support the hypothesis of the secondary hypoparathyroidism in thyrotoxicosis and hyperparathyroidism--in the hypothyroidism.
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PMID:[Studies of calcium-phosphorus metabolism in thyrotoxicosis]. 91 16

The 2- and 8-azido trimer 5'-triphosphate photoprobes of 2-5A have been enzymatically synthesized from [gamma-32P]2-azidoATP and [alpha-32P]8-azidoATP by 2-5A synthetase from rabbit reticulocyte lysates. Identification and structural determination of the 2- and 8-azido adenylate trimer 5'-triphosphates were accomplished by enzymatic hydrolyses with T2 RNase, snake venom phosphodiesterase, and bacterial alkaline phosphatase. Hydrolysis products were identified by HPLC and PEI-cellulose TLC analyses. The 8-azido photoprobe of 2-5A displaces p3A4[32P]pCp from RNase L with affinity equivalent to p3A3 (IC50 = 2 X 10(-9) M in radiobinding assays). The 8-azido photoprobe also activates RNase L to hydrolyze poly(U) [32P]pCp 50% at 7 X 10(-9) M in core-cellulose assays. The 2- and 8-azido photoprobes and authentic p3A3 activate RNase L to cleave 28S and 18S rRNA to specific cleavage products at 10(-9) M in rRNA cleavage assays. The nucleotide binding site(s) of RNase L and/or other 2-5A binding proteins in extracts of interferon-treated L929 cells were investigated by photoaffinity labeling. Dramatically different photolabeling patterns were observed with the 2- and 8-azido photoprobes. The [gamma-32P]2-azido adenylate trimer 5'-triphosphate photolabels only one polypeptide with a molecular weight of 185,000 as determined by SDS gel electrophoresis, whereas the [alpha-32P]8-azido adenylate trimer 5'-triphosphate covalently photolabels six polypeptides with molecular weights of 46,000, 63,000, 80,000, 89,000, 109,000, and 158,000. Evidence that the photolabeling by 2- and 8-azido 2-5A photoprobes was highly specific for the p3A3 allosteric binding site was obtained as follows.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:2- and 8-azido photoaffinity probes. 1. Enzymatic synthesis, characterization, and biological properties of 2- and 8-azido photoprobes of 2-5A and photolabeling of 2-5A binding proteins. 324 13

Porfiromycin was reductively metabolized by NADPH cytochrome P-450 reductase and xanthine oxidase under anaerobic conditions. The production of metabolites varied with the pH and the contents of the reaction buffer. In Tris buffer, two major metabolites were produced at pH 7.5 and above, whereas one major metabolite was produced at pH 6.5. The three major metabolites were separated and isolated by HPLC. Identification by californium-252 plasma desorption mass spectrometry showed that the two major metabolites from pH 7.5 were (trans) and (cis)-forms of 7-amino-1-hydroxyl-2-methylaminomitosene and the major metabolite from pH 6.5 was 7-amino-2-methylaminomitosene. All three major metabolites showed substitutions at the C-1 position. DNA was alkylated readily by enzyme-activated porfiromycin. Digestion of porfiromycin-alkylated DNA by DNase, snake venom phosphodiesterase, and alkaline phosphatase resulted in an insoluble nuclease-resistant fraction and a soluble fraction. The nuclease-resistant fraction reflected a high content of cross-linked adducts. Upon HPLC analysis, the solubilized fraction contained two monofunctionally linked porfiromycin adducts and a possibly cross-linked dinucleotide. The major adduct was isolated by HPLC and identified by NMR, as N2-(2'-deoxyguanosyl)-7-amino-2-methylaminomitosene. The N2 position of deoxyguanosine appeared as the major monofunctional alkylating site for DNA alkylation by porfiromycin. Thus, mitomycin C and porfiromycin (which differs from mitomycin C only by the addition of a methyl group to the aziridine nitrogen) share the same enzymatic activating mechanism that leads to the formation of the same types of metabolites and the same specificity of DNA alkylation.
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PMID:Metabolites and DNA adduct formation from flavoenzyme-activated porfiromycin. 341 25

A (2'-5')An synthetase activity was isolated from human placental extracts by affinity chromatography on poly(rI) . poly(rC)-agarose. The oligonucleotide (2'-5')An was identified by (1) chromatography on PEI-cellulose and DEAE-cellulose, (2) inhibition of polypeptide synthesis in lysed rabbit reticulocytes (3) competition of the binding of pppA(pA)3,3'-[32P]pCp to rabbit reticulocyte lysates, and (4) alkaline phosphatase digestion. The synthetase activity in most placental preparations is activated by natural or synthetic dsRNA. However, in a few placental synthetase preparations, dsRNA is only marginally stimulatory and only becomes effective by prior treatment of the enzyme preparations with the calcium-dependent micrococcal nuclease. This suggests that there is an endogenous placental dsRNA contaminant in the enzyme preparations. In some synthetase preparations, a second dsRNA-stimulated product, tentatively identified as the nucleotide 5'-IMP, is also observed. Because the specific AMP deaminase inhibitor coformycin (10 microM) blocks the formation of IMP from ATP and causes a quantitative accumulation of AMP, and because the formation of IMp becomes independent of dsRNA when ADP or AMP is used in place of ATP, the presence of a dsRNA-stimulated ATP phosphohydrolase (ATPase) activity in human placenta is suggested.
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PMID:Double-stranded RNA-stimulated enzyme activities isolated from human placental extracts. 662 76

Sea urchin embryos were labeled with [3H]adenosine at two developmental stages (morula and prism) and the labeled acid-soluble nucleotides were fractionated successively by column chromatography with DEAE-Sephadex and DEAE-cellulose, and by thin-layer chromatography on a PEI-cellulose plate. Significant radioactivity was detected on the PEI-cellulose plate at the region of diadenosine 5',5'''-P1,P4-tetraphosphate (AP4A). After treatment of this fraction with phosphodiesterase, the radioactivity was all recovered in the AMP region, while alkaline phosphatase had no effect on the AP4A fraction. The present result suggests that AP4A is actively synthesized in the sea urchin embryos.
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PMID:Synthesis of diadenosine 5',5'''-P1,P4-tetraphosphate (AP4A) in sea urchin embryos. 672 90

8-Methoxypsoralen is a bifunctional furocoumarin used in human photochemotherapy. It can form two kinds of DNA adduct, monoadducts and interstrand cross-links. These adducts have been detected by 32P-postlabelling using hydrolysis with DNase1, alkaline phosphatase and snake venom phosphodiesterase, and longer labelling than usual, with more T4 polynucleotide kinase. Using preliminary two-dimensional chromatography (D1, D2) followed by transfer of adducts to separate PEI cellulose sheets for further development (D3, D4), we observed three spots corresponding to the adducts sought. Two experiments (dose-effects and shift of radioactivity) have confirmed the origin of the three spots.
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PMID:Characterization by 32P-postlabelling of 8-methoxypsoralen adducts. 822 76

A tritium derivative method for sequence analysis of polyribonucleotides is detailed, which is based on borotritide reduction of oligonucleotide-3' dialdehydes generated by controlled snake venom phosphodiesterase/alkaline phosphomonoesterase digestion and periodate treatment of time point aliquots of the incubation mixture. Radioactive oligonucleotide derivatives are resolved according to chain length by PEI-cellulose(1) anion-exchange TLC and their 3'-termini identified by techniques described in the preceding paper of this series(2). The present tritium derivative method is compared with the one described previously(2).
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PMID:Tritium sequence analysis of oligoribonucleotides: a combination of post-labeling and thin-layer chromatographic techniques for the analysis of partial snake venom phosphodiesterase digests. 1079 93


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