In liver extracts

Shenoy, K. G., and Ramasarma, G. B., Iron as a stabilizer of vitamin B12 activity in liver extracts and the nature of so-called alkali-stable factor. Arch. Bio-chem. Biophys. 55, 293-295 (1955). 

Mice (18—20g) were intravenously injected with 10 ug of plasmid DNA in 1.6 ml saline. Mice were sacrificed eight hours after injection and luciferase protein in liver extracts was measured according to procedure in (Liu et al., 1999). Data represent mean (SD), n=3. 

Holtzapple et al. developed an immunoassay method for determination of four fluoroquinolone compounds (including ciprofloxacin) in liver extracts [64]. In this method, an immunoaffinity capture SPE column was used, that contained anti-sarafloxacin antibodies covalently cross-linked to protein G. After interfering liver matrix compounds had been washed away, the bound ciprofloxacin was eluted directly onto the HPLC column. The HPLC system used a 5 pm Inertsil phenyl column (15 cm x 4.6 mm i.d.), with 0.1 M-glycine hydrochloride/acetonitrile (17 3) as the mobile phase (eluted at a rate of 0.7 mL/min). Fluorimetric detection at 444 nm was used after excitation at 280 nm. The recovery of ciprofloxacin ranged from 85.7 to 93.5%, and the detection limit was... 

Hg binding to MTs observed in kidney but not in liver extracts. Further characterization with ESI-MS allowed the identification of several complexes, containing only Hg and/or Hg and Cu... 

The anesthetic compound halothane, CF3CHBrCl, is metabolized in the liver and this process has been monitored using F NMR spectroscopy, both in vivo and in dissected rat livers. Initially, several resonances were observed in vitro which did not correspond to trifluoroacetate or fluoride, two known metabolic products. Using surface coil NMR experiments in vivo, it has been possible to show that the halothane has a first-order decay in the liver with a half-life of 2.5 h, that trifluoroacetate was observed 8 h after dosing, and that induction of liver enzymes shortened this period considerably. No other resonances were observed in vivo but in liver extracts other molecules were also detected, namely, fluoride, CF3CH2CI, and CHF2CH2CI. 

An inhibitory effect on orotidylic acid decarboxylase was also observed following 5-azacytidine [253,254], another highly active cytostatic agent [253-256]. The direct action of 5-azacytidine 5 -phosphate on enzyme activity in vitro has not yet been measured and the evidence for its interaction with the transformation of orotic acid came from the observation that 5-azacytidine increases its urinary excretion in mice [257,258]. The activity of orotidylic acid decarboxylase in liver extracts from 5-azacytidine-treated animals was also decreased in comparison to controls [258]. 

Fig. 3. Activity gel analysis of poly(ADP-ribose) transferase in liver extracts from rats exposed to a 4-cycle discontinuous feeding regimen containing 0.05% 2AAF (panel A) of 0.05% 2AAF + 0.1% NAC (panel B). Each autoradiogram shows in lane 1 the poly(ADP-ribose) transferase activity band of control animus, and in lanes 2, 3, 4, and 5 the activity bands after the 1,2,3 and 4 cycle of treatment, respectively.

These antibiotics, which show antitumour activity, strongly inhibit the synthesis of purines in liver extracts and cause the accumulation of the formyl derivative of A -glycylribosylamine 5-phosphate (LIX). Under normal conditions the latter reacts with glutamine and ATP, in the presence of a liver enzyme, to form the amidine LX. Buchanan has shown that azaserine (XXIX) and DON (XXX) inhibit this reaction specifically, by competing with glutamine for the enzyme sitei s. After combining with the enzyme the... 

Be deficiency was found to reduce transfer of sulfur from homocysteine to serine, and this could be restored in liver extracts by the addition of pyridoxal phosphate. Binkley et oZ. reported the activation of both the cystathionine-synthesizing enzyme and the cleavage enzymes by pyridoxal phosphate. 

A reaction similar in type to that described above has been demonstrated in liver extracts by Wajzer and Baron for inosine-3 -phosphate synthesis from hypoxanthine and ribose-3-phosphate. The formation of the mononucleotide, adenylic acid, by the phosphorylation of adenosine by adenosinetriphosphate has also been described. The significance and integration of these different reactions remains a major problem for future effort. 

We have also subjected mouse liver enzyme to electrophoresis at pH 7.5, in contrast to the system already described which runs at pH 9.5. As shown by the gel on the left side of Fig. 11, liver glucuronidase activity of DBA mice is resolved into five components after electrophoresis in the pH 7.5 system. The intensely staining anodal component represents lysosomal enzyme, since it is the only component observed in liver extracts of YBR mice, as shown by the gel on the right side of the Fig. 11. The other four components of DBA enzyme are presumably of microsomal origin, being unresolved in the pH 9.5 system where they migrate as a single component. 

Relative Monoamine Oxidase Activitt as Maximum Oxidation Rates (Pee Cent) in Liver Extract Relative to Phenethtlamine HB) ... 

Formation of kynurenine from tryptophan was discovered in liver extracts by Kotake and Masayama 289). These authors proposed the name tryptophan pyrrolase for the enzyme. Knox and Mehler 290) subsequently showed that the formation of kynurenine consisted of two enzyme reactions, an initial oxidation to formylkynurenine followed by hydrolysis to kynurenine. Because the reaction was stimulated by HsO produced in situ it was assumed that there was an intermediate formation and utilization of peroxide in the oxidation. For this reason the enzyme was renamed tryptophan oxidase-peroxidase by Knox. Experiments with O showed that molecular O2 was incorporated into the reaction products 291). One mole of O2 per mole of tryptophan was contained in the formylkynurenine. When H20 was tested, very little 0 was utilized. This observation led Tanaka and Knox 292) to return to the use of the original name, tryptophan pyrrolase. 

Gitzelmann, R., Steinmann, B., Bally, C., and Lebherz, H. G., 1974, Antibody activation of mutant human fructosediphosphate aldolase B in liver extracts of patients with hereditary fructose intolerance, Biochem. Biophys. Res. Commun. 59 1270. 

Uridine diphosphate-V-acetylglucosamine (UDP-GlcNAc) was first found in yeast (Cabib et aL, 1953) and in liver extracts (Smith et al., 1953 Hurlbert and Potter, 1954). Smith et al., (1953) also demonstrated that rat liver nuclei could degrade UDP-GlcNAc by a reversal of the pyrophosphorylase reaction. 

Following the suggestion in his first paper (54) that further investigation of the possible role of glucosamine and the common amino acids (especially leucine and tyrosine) in the pernicious anemia problem might be desirable, he subsequently studied the role of tyrosine (55). Using methods employed by Raper and associates in the identification of substances present in a reaction mixture of tyrosine and tyrosinase, Jacobs concluded that the red substance in liver extract is the 5,6-quinone of dihydroindole-2-carboxylic acid. 

They next attempted to test for heparin in liver extracts of proved activity, (those used were called Pernaemon and Sykoton). A positive Molisch reaction, in the absence of glycoprotein, polysaccharides and monoses indicated the probable presence of heparin. Their attempt to isolate heparin in crystalline form from Pernaemon proved unsuccessful. 

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