Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The minor enzyme of human prostatic acid phosphatases (pI 5.5) with high specific activity (orthophosphoric monoester phosphohydrolase, acid optimum, EC 3.1.3.2) has been purified for the first time as a pure enzyme protein. The enzyme was a single protein when examined by polyacrylamide gel electrophoresis and isotachophoresis. The specific activity was 1080 micromole per (min X mg) for hydrolysis of 5.5 mmole per liter of p-nitrophenylphosphate at pH 4.8 and 37 C. The purification coefficient was 540 and the recovery of enzyme activity was 2 per cent. The molecular weight of the enzyme subunit when measured by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate was 54,000. The Km of the purified enzyme was 3 X 10(-4) mole per liter for p-nitrophenylphosphate. An antiserum to this enzyme was prepared. The enzyme was cross-reactive with the main enzyme (pI 4.9) of human prostatic acid phosphatases in immunoelectrophoresis. No precipitin arc with the acid phosphatase in the serum of a prostatic carcinoma patient could be shown. Antiserum to the main enzyme caused a precipitin line with the same serum sample.
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PMID:Human prostatic acid phosphatases: purification of a minor enzyme and comparisons of the enzymes. 42 30

The interaction between immobilized antibodies against human immunoglobulin G (IgG) and the immunoenzyme complex IgG-peroxidase (IgG-P) was studied. The complex was obtained by covalent binding of IgG to peroxidase modified by sodium periodate. Study of the IgG-P binding kinetics and dissociation of the antibody-(IgG-P) complex showed that the antibodies immobilized on Sepharose reversibly interacted with IgG-P, similar to the antigen-antibody reaction in solution. The efficient values of the binding constants for the antibodies binding to Sepharose covalently and through the antigen-antibody bond are (2,2+/-0,5) 10(8) M-1 and (4,2+/-0,2) 10(8) M-1, respectively. The nature of a carrier and the immobilization method used do not significantly affect the rate of the complex binding to the antibodies. The activation energy of the reaction of IgG-P binding to the antibodies immobilized on Sepharose covalently and through the antigen-antibody bond is 7,3 and 4,1 kcal/mole, respectively. A procedure of titration of immobilized antibodies active sites with the antigen-enzyme complex is discussed.
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PMID:[Interaction between immobilized antibodies and the antigen-enzyme complex]. 43 70

Using the technique of affinity chromatography on a myo-inositol-substituted Sepharose, the myo-inositol oxygenase from rat kidneys was purified to homogeneity. The active enzyme contains iron, most probably in its divalent form. Electrophoresis on polyacrylamide gel containing sodium dodecylsulphate causes the cleavage of the enzyme protein into apparently identical subunits with a molecular weight of approximately 17,000. The smallest active unit consists of 4 subunits, and is in a pH-dependent equilibium with species consisting of 8, 12, and 16 subunits, respectively, which all show the same specific enzyme activity. In the presence of oxygen the enzyme is highly unstable; at the early stages of inactivation it can be reactivated by reducing agents like NaBH4. Under anaerobic conditions or under the influence of Fe2-chelating agents, the enzyme is also inactivated; this inactivation is caused by the loss of iron and concomitant cleavage into the subunits. It can be reversed by incubation with FeSO4 in the presence of air. If myo-inositol and FeSO4 are present, the reactivation involves an oligomerization to the species with 16 subunits with the uptake of 8 gram-atoms of iron per mole of this species. The enzyme reaction follows Michaelis-Menten kinetics; the Michaelis constants are 4.5 x 10(-2)M for myo-inositol and 9.5 x 10(-6)M for oxygen.
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PMID:myo-Inositol oxygenase from rat kidneys. I: Purification by affinity chromatography; physical and catalytic properties. 43

Ruminal papillae were biopsied from fasted adult sheep given 18 m mole/kg body weight per day of sodium propionate or sodium acetate intraruminally via fistula. The mitotic index of the epithelial cells in the papillae was estimated for the mitogenic effect of the acids. Before the administrations, mitotic indices were lower than .53%. They increased after a few days' propionate-administration, then declined. The peak values appeared on 2 or 4 days of the administration and were 1.64%, 1.38%, 1.73%, and 1.54% in four trials. Mitotic indices also increased from acetate and declined. The peak values appeared on 3 or 4 days of the administration and were 2.04%, 2.49%, 1.70%, and 2.03% in four trials. Mitotic indices of the control sheep given the same amount of .9% saline were lower than .28%. The mitogenic effect of propionate and acetate on the rumen epithelial cells was apparent, but it seems to be weaker than that of butyrate judged from the relatively slow rise of the index in this study.
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PMID:Rumen epithelium cell proliferation accelerated by propionate and acetate. 45 76

The reactions of sodium nitrite and methapyrilene were studied in aqueous solution at neutral pH and under simulated gastric fluid conditions. Reaction product formation was much more complex than nitrosation of the parent molecule dimethylamino moiety to form nitrosodimethylamine. Several new nitroso compounds were formed under the reaction conditions studied. The simultaneous incorporation of 2 moles of ascorbic acid/mole of nitrite ion prevented any destruction of methapyrilene under all conditions studied. The implications of these observations with respect to nitrosation theory, the general carcinogenicity of nitroso compounds, and methapyrilene dosage formulation are discussed.
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PMID:In vitro nitrosation of methapyrilene. 45 97

Some properties of homogeneous transketolase from pig liver were studied. It was shown that the pH optimum of the transketolase reaction lies within the range of 7.8--8.2. The isoelectric point is at pH 7.6--7.8. The molecular weight of transketolase is 138,000 +/- 3,000 as determined by the sedimentation equilibrium method and about 152,000 according to the data from gel filtration through Sephadex G-200. The enzyme molecule is a tetramer of the alpha 2 beta 2 type. The molecular weights of the alpha- and beta- subunits determined by polyacrylamide gel in the presence of sodium dodecyl sulfate are 52,000--56,000 and 27,000--29,000, respectively. Transketolase contains about two moles of TPP per mole of protein and does not require metal ions for its catalytic activity.
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PMID:[Properties of pig liver transketolase]. 46 97

1. Theophylline (10 mM) and choleragen (1 x 10(-6) g ml.-1) abolish net fluid absorption by everted sacs of rabbit ileum. Triaminopyrimidine (20 mM) and ethacrynate (0.1 mM) prevent this inhibition of net fluid movement. Replacing Ringer Cl- with isethionate prevents the theophylline-dependent decrease in fluid absorption also. 2. Ouabain (0.1 mM) abolishes net fluid movements in both control and theophylline-treated tissue. 3. With ouabain present, hypertonic NaCl (200 mM) in the mucosal solution causes net fluid secretion (serosal-mucosal flux). With theophylline added to both the mucosal and serosal solution, net fluid absorption (mucosal-serosal flux) is observed (P less than 0.001). Triaminopyrimidine (20 mM), or ethacrynate (0.1 mM), or replacement of Ringer Na+ with choline, or Ringer Cl- with isethionate all prevent the theophylline-induced reversal of osmotic flow. 4. Theophylline increases passive net flux of Na+ and Cl- from mucosal solution containing hypertonic (200 mM) NaCl+ ouabain (0.1 mM) across sheets of ileum into serosal solution containing mannitol Ringer + ouabain. The increased passive Na+ flux is blocked by triaminopyrimidine and the increased Na+ and Cl- fluxes are blocked by ethacrynate (0.1 mM). 5. The suggested route of increased NaCl leakage is via the paracellular pathway as it is inhibited by triaminopyrimidine. The increase, itself, is a consequence of the increased passive permeability of the mucosal border to Cl-, induced by theophylline or choleragen. Water is apparently electro-osmotically coupled to the paracellular Na+ leakage (100 mole water mole-1 Na+), hence increased passive leakage reverses osmotic flow. In active tissue the lateral intercellular space contains hypertonic NaCl, and hence increased leakage of NaCl across the tight-junction in theophylline or choleragen-treated tissue gives rise to net fluid secretion.
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PMID:Fluid movements across rabbit ileum coupled to passive paracellular ion movements. 46 72

Isolated ganglia possess the ability to concentrate tryptamine from an external medium by a process which is temperature sensitive and independent of sodium and other cations. Kinetic analysis of the accumulation process showed the influx of tryptamine to be a single mechanism with Km and Vmax values of 1.4 X 10(-4)M and 5 X 10(-8) mole/g/min. The influx of tryptamine is an unspecific process and is insensitive to a number of metabolic inhibitors and various analogues. The process of tryptamine influx is thus similar in principle to the low affinity uptake mechanism for 5-HT (see Osborne et al., 1975). The present data, which include some experiments on the release of 5-HT and tryptamine, are discussed from the point of view of a functional role for 5-HT and tryptamine in the snail CNS.
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PMID:The influx of tryptamine into snail (Helix pomatia) ganglia: comparison with 5-hydroxytryptamine. 49 55

Four polypeptide chains composing acetylcholine receptors from the electric organ of Torpedo californica were purified by preparative electrophoresis in sodium dodecyl sulfate. Their apparent mole ratio alpha/beta/gamma/delta is 2:1:1:1. These chains are not readily distinguished by amino acid or carbohydrate composition but are distinguished by apparent molecular weight and polypeptide maps. By peptide maps, no extensive homology is evident between these chains or between any of these chains and higher molecular weight chains found in receptor-enriched membrane fragments.
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PMID:Biochemical properties of acteylcholine receptor subunits from Torpedo californica. 49 50

The parameters which influence the in vitro cytotoxicity of positively charged liposomes for L 1210 cells were analyzed. The cytotoxicity was liposome/cell ratio-dependent. It also depended upon the mole fractions of stearylamine (SA) to phosphatidylcholine (PC). There was no difference between the cytotoxicity of unilamellar and multilamellar vesicles but the cytotoxic effect of free SA was about 4 times greater than that of liposome incorporated SA at a molar ratio of 1:4, SA:PC, respectively. The process which resulted in cell death was irreversible after 60 min of cell-liposome contact. The simultaneous presence of neutral liposomes or of positively charged liposomes with a lesser charge density decreased the cytotoxic effect of liposomes with a higher SA content. The cytotoxicity could be decreased by trypsinization of cells following exposure to liposomes while treatment of cells with trypsin prior to the exposure to positively charged liposomes had no effect on the subsequent cytotoxicity. The cytotoxicity was also decreased if cells were incubated in the presence of sodium azide. The usual concentration of serum (10%) present in the growth medium had no effect on the cytotoxicity while preincubation of cells with liposomes in 80% serum resulted in full protection. The protective effect of serum could be replaced by the albumin fraction.
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PMID:Control of in vitro cytotoxicity of positively charged liposomes. 50 Jul 67


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