Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: HUMANGGP:003721 (Poly)
 11,742 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly (2'-amino-2'-deoxyadenylic acid) [poly (Aa)] was prepared from chemically synthesized 2'-amino-2'-deoxy-ADP by the catalysis of polynucleotide phosphorylase. Poly (Aa) showed a similar UV absorption spectra to poly (A), but quite different CD spectra at pH 7.0 and 5.7. At the former pH it showed a single negative Cotton band and at the latter a curve with a large splitting of bands. Acid titration of poly (Aa) suggested protonated form below pH 7.0. Temperature absorption profiles and their dependency on sodium ion concentration suggested an ordered structure for poly (Aa) which is stabilized by stacking of bases and intrastrand interaction between 2'-amino and internucleotidic phosphate groups. Poly (Aa) forms a 1:2 complex with poly (U) at neutrality and its Tm was 45 degrees in the presence of 0.15M sodium ion.
 ...
PMID:Polynucleotides. XLVI. 1 Synthesis and properties of poly (2'-amino-2'-deoxyadenylic acid). 1 2

Human urine RNase was purified about 2000-fold. The preparation is free from phosphatase, phosphodiesterase and DNase activities. On electrophoresis through polyacrylamide gel at pH 8.3, it migrates toward the anode and stains with periodic acid-Schiff reagent, suggesting that it is acidic and glycoprotein in nature. Its isoelectric point is at pH 4.1. It has a molecular weight of about 21,500. It is thermostable at pH 4.2 and thermolabile at pH 8.5. It has a pH optimum at 6.5. It exhibits highest preference for cytidine 3'-phosphate linkages. Its activity on poly (C) is endonucleolytic. It cleaves poly (C) via intramolecular transphosphorylation. It has no action on cytidine 2': 3'-cyclic phosphate or uridine 2':3'-cyclic phosphate. Its rate of hydrolysis of poly (U) is less than 2% of that of poly C). Poly (A) and poly (G) are totally inert to its action. Its action on poly (C) is inhibited by poly (G), poly (A) and poly (U). It differs from bovine pancreatic Rnase A in its physical, chemical and catalytic properties. It is, however, similar to human serum and pancreatic RNase in all its properties, suggesting that pancreas is its likely source.
 ...
PMID:Purification and properties of a ribonuclease in human urine that hydrolyses polycytidylic acid. 2 Jun 15

An endo-type, cyclising, 3'-phosphate-forming rebonuclease was purified to homogeneity from a water/Tween 80 extract of human hypertrophic prostate gland. The enzyme is acid- and heat- resistant and is optimally active at pH 7.0, 0.1 M NaCl. Molecular weight determined by gel filtration on Sephadex G-75 and sucrose density gradient centrifugation gave a mean value of 15 000. The prostatic ribonuclease is inhibited by Cu2+, bromoacetate and photooxidation in the presence of methylene blue. Other divalent ions, EDTA and p-chloromercuribenzoate have no influence on the enzymic activity. Prostatic RNase resembles RNase A in that it preferentially cleaves linkages in RNA after pyrimidine nucleotides to produce oligonucleotides terminated in cyclic 2',3' phosphate. The enzyme is inactive with poly(A) - poly(U) as substrate. Poly(U) is hydrolyzed four times as fast as poly(C), and 1.2 times as fast as RNA.
 ...
PMID:Preparation and characterisation of ribonuclease from human hypertrophic prostate gland (RNAase P2). 5 49

The biochemical properties of DNA polymerase purified from Mason-Pfizer monkey virus were studied, with respect to synthetic and natural template-primer utilization. Thes studies revealed the following new information about the Mason-Pfizer monkey virus enzyme: (a) Mason-Pfizer monkey virus polymerase was found to prefer template: primer molar nucleotide ratios of 2.5-5: 1 for optimal rates of synthesis with poly(C) .(dG)12-18 as template-primer. (b) Poly(A)-directed synthesis was stimulated by the addition of low concentrations of inorganic phosphate to the reaction mixture. (c) Poly(2' -O-methyl-cytidylate), poly(rCm), was the only template studied for which Mn2+ proved the preferred divalent cation. Combinations of divalent cations stimulated rather than inhibited poly(rCm)-directed poly(dG) synthesis by the Mason-Pfizer monkey virus enzyme. (d) Heteropolymeric regions of rabbit globin mRNA and avian myeloblastosis virus 70 S RNA could be copied by the Mason-Pfizer monkey virus polymerase with oligo(dT), oligo(U) or in the case of avian myeloblastosis virus RNA, endogenous primers. In all such studies, Mg2+ was the preferred divalent cation and a distinct preference for the DNA primer in the reverse transcription of natural RNAs was observed. These new findings necessitated comparative studies with the DNA polymerases from Rauscher murine leukemia virus and murine mammary tumor virus, as representative type C and type B retroviruses. Although the Mason-Pfizer monkey virus enzyme was found to share some properties in common with both type C and type B mammalian viral enzymes, certain of the above properties rendered it unique among the polymerases examined.
 ...
PMID:Template-specific requirements for DNA synthesis by the Mason-Pfizer monkey virus DNA polymerase: unique aspects. 7 24

A four-fold transient rise in c-AMP levels was seen when sensitized guinea-pig lungs were challenged with antigen in vitro. This rise in c-AMP also occurred in vivo and was shown to be due to release of Prostaglandin E2. This conclusion is supported by the finding that inhibitors of prostaglandin synthesis (Indomethacin and Poly phloretin phosphate) prevent the rise in c-AMP while neither ICI 74, 917, an inhibitor of histamine release, nor antihistamines had any effect on the c-AMP levels.
 ...
PMID:The relationship between prostaglandin release and lung c-AMP levels during anaphylaxis in the guinea-pig. 17 83

The blood clearance of all current bone-seeking radiopharmaceuticals is biexponential during the first four hours after injection. Exponent I represents bone uptake and its clearance half-time is less than 30 min. Exponent II represents mainly urinary excretion and its clearance half-time varies from 168 to 512 min. The blood background is highest with 99mTc-labeled polyphosphate (Tc-Poly) and lowest with sodium fluoride (F-18); 99mTc-labeled diphosphonate (Tc-Dip) and 99mTc-labeled pyrophosphate (Tc-Pyro) show intermediate blood levels. The slower blood clearance of 99mTc-phosphate complexes in comparison with F-18 is due primarily to their increased protein binding. Tc-Poly blood clearance, which is slower than that of Tc-Dip and Tc-Pyro, is due primarily to its increased red cell binding and the larger size of its molecule. Bone uptake and urinary excretion of all 99mTc-labeled phosphate complexes are approximately the same: in the range of six to ten per cent in the blood, 30-33% in the urine, and 55-58 percent in the bone and other tissues. F-18 concentration in the bone is almost 1.5 times that of the 99mTc-labeled phosphate complexes. The sensitivity and resolution of lesions are identical for all 99mTc-labeled phosphate complexes and are far better than those for F-18. No toxicity is noted with the amount of phosphate present in the marketed kits, and it appears reasonable to use the minimal amount so long as efficiency is not compromised.
 ...
PMID:Pharmaco-kinetics of current skeletal-seeking radiopharmaceuticals. 17 99

An endoribonuclease has been isolated from HeLa cell nuclei. Approximately 70% of the enzyme appears to be nucleolar bound; 30% is in the nucleoplasm. Studies of the purified enzyme reveal that the enzyme is an endonuclease of estimated molecular weight 16,000. It produces oligonucleotides bearing 5'-phosphate end groups. The enzyme degrades poly(C) and poly(U), as well as rRNA and heterogeneous nuclear RNA, Poly(A), double-stranded RNA, and DNA are not cleaved. The enzyme is heat-labile and is inhibited by 10mM Mg2+ and 50 mM NaCl. The enzyme is probably distinct from previously described nuclear endonucleases.
 ...
PMID:Purification and characterization of an endoribonuclease from nucleoplasm and nucleoli of HeLa cells. 18 53

Poly([14C]adenosine diphosphate ribose) was synthesized from [14C]NAD+ with calf thymus nuclei. The fraction containing poly(adenosine diphosphate ribose) eluted with 0.22--0.40 M phosphate buffer (pH 6.8) from a hydroxylapatite column, was completely hydrolyzed with venom phosphodiesterase, and was separated by DEAE-Sephadex A-25 column chromatography in 7 M urea. A new compound, which constituted 2% of the products from poly(adenosine diphosphate ribose), was found in addition to the expected products--i.e., 5'-AMP, 2'-(1''-ribosyl)adenosine-5',5''-bis(phosphate), and its derivatives. This compound was identified as 2'-[1''-ribosyl 2''-(or 3''-)(1'''-ribosyl)]adenosine-5',5'',5'''-tris(phosphate). The existence of this compound is evidence of a branching structure of poly(adenosine diphosphate ribose), which was previously thought to be a linear molecule. The content of this compound suggests that the frequency of branching is about 1 per 20--30 adenosine diphosphate ribose residues of high molecular weight poly(adenosine diphosphate ribose).
 ...
PMID:Structure of poly(adenosine diphosphate ribose): identification of 2'-[1''-ribosyl-2''-(or 3''-)(1'''-ribosyl)]adenosine-5',5'',5'''-tris(phosphate) as a branch linkage. 21 10

The effects of added polyamines on carbamylphosphate (carbamyl-P):glucose phosphotransferase and glucose-6-phosphate (Glc-6-P) phosphohydrolase activities of rat hepatic D-Glc-6-P phosphohydrolase (EC 3.1.3.9) of intact and detergent-treated microsomes have been investigated. With the former preparation, in the presence of 1.4 mM phosphate substrate and 90 mM D-glucose (phosphotransferase), 1 mM spermine, spermidine, and putrescine activated Glc-6-P phosphohydrolase 67%, 57%, and 35%, respectively. Carbamyl-P:glucose phosphotransferase, under comparable conditions, was activated 57%, 34%, and 18%. NH+4 (0.25--5.0 mM) produced at best but a minor activation (0--14%), while poly(L-lysine) (Mr = 3400; degree of polymerization 16) equimolar relative to other polyamines with respect to ionized free amino groups activated the hydrolase 358% and the transferase 222%. Treatment of microsomes with the detergent deoxycholate reduced, but did not abolish, polyamine-induced activation. The stimulatory effects of polyamines persisted in the presence of excess catalase, indicating their independence from H2O2 formation; and were eliminated in the presence of Ca2+. Kinetic analysis revealed that all tested polyamines decreased the apparent Michaelis constant values for carbamyl-P and Glc-6-P, but had no effect on the Km for glucose. Poly(L-lysine) increased the V value for both Glc-6-P phosphohydrolase and apparent V values for phosphotransferase extrapolated to infinite concentrations of either carbamyl-P or glucose. The other tested polyamines elevated only this last velocity parameter. It is proposed that a major mechanism by which polyamines activate glucose-6-phosphatase-phosphotransferase is through their electrostatic interactions with phospholipids of the membrane of the endoplasmic reticulum of which this enzyme is a part. Conformational alterations thus induced may in turn affect catalytic behavior. It is suggested that polyamines, or similar positively charged peptides, might participate in the cellular regulation of synthetic and hydrolytic activities of glucose-6-phosphatase.
 ...
PMID:Stimulation by polyamines of carbamylphosphate:glucose phosphotransferase and glucose-6-phosphate phosphohydrolase activities of multifunctional glucose-6-phosphatase. 22 Oct 50

Gas-liquid chromatography GLC) coupled with column chromatography was used to accurately determine as little as 25 ppm p-chloroacetanilide in acetaminophen. p-Chloroacetanilide was eluted from a pH 8 phosphate-buffered diatomite partition column by using purified tetrachloroethylene (acetaminophen was retained). This solution was concentrated, internal standard (docosane) was added, and p-chloroacetanilide was determined by using a 0.9 m X 2 mm glass column packed with 3% Poly A 103 on Supelcoport and a flame ionization detector with electronic integration. Standard curves were linear for 10-100 ppm p-chloroacetanilide. Various chromatographic materials were investigated for optimal retention characteristics. High pressure liquid chromatography (HPLC) was also evaluated as an alternative; however, lack of reproducibility of the HPLC column favored the GLC procedure.
 ...
PMID:Gas-liquid chromatographic determination of p-chloroacetanilide in acetaminophen. 62 Nov 96


1 2 3 4 5 6 7 8 9 10 Next >>