Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A nucleic acid methylase, N2-guanine ribonucleic acid (RNA) methyltransferase, which is associated with type C RNA tumor viruses, has been purified from avian myeloblastosis virions by gel filtration on Sephadex G-200, followed by chromatography on hydroxylapatite. The molecular weight estimated by gel filtration is 220 000, and the methylase activity has a pH optimum of 7.6--7.9. Magnesium and ammonium ions both stimulate activity 1.5-fold at 9.5 mM and 0.36 M, respectively, but apparently neither is essential for activity. Both daunomycin and adriamycin, antineoplastic drugs, also increase activity 1.5-fold at 1 mM. The enzyme was purified 120-fold from the virions and the activity is partially stabilized by dithiothretiol, but large losses were sustained during 24-h dialysis. The purified enzyme retains 75% of its activity on storage at -25 degrees C for 2 months in buffer containing 50% glycerol. Escherichia coli tRNAPhe and tRNAVal are preferred substrates with methylation occurring at position 10 of E. coli tRNAPhe.
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PMID:Partial purification and characterization of a ribonucleic acid N2-guanine methyltransferase associated with avian myeloblastosis virus. 22 52

The avian sarcoma virus src gene product, p60src, has been purified 650-fold from cytoplasmic extracts of the rat tumor cell line RR1022 by using ammonium sulfate fractionation, hydrophobic chromatography on omega-aminohexyl agarose, and ion exchange chromatography on phosphocellulose. Partially purified p60src is a monomer, with a native molecular weight of about 60,000 and an apparent pI of 6.0. In immunoprecipitates, p60src catalyzed phosphorylation of anti-p60src IgG heavy chains within the variable (VH) domain, which contains the heavy chain portion of the antigen combining site. Crude preparations of p60src contained phosphatase activity able to cleave phosphate from IgG heavy chains; this activity was removed by the purification procedure, and partially purified p60src could phosphorylate the heavy chain of specific antibody in solution. Furthermore, purified p60src catalyzed phosphorylation in solution of the general protein kinase substrate, alpha-casein, strengthening the hypothesis that it may in fact function as a protein kinase in vivo.
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PMID:Characterization of the protein kinase activity of avian sarcoma virus src gene product. 22 74

The major ribonuclease of adult guinea pig epidermis has been isolated and purfied over 1000-fold by a combination of ammonium sulfate fractionation, affinity and ion-exchange chromatography, and electrophoresis. The purified enzyme is free from phosphodiesterase and phosphatase activities. The ribonuclease is optimally active near neutrality in phosphate buffer, with a Km of 3mu g/ml toward [14-C]RNA from Erhlich ascites tumor cells. (here are no metal requirements for activity. The enzyme catalyzes the endonucleolytic hydrolysis of high molecular weight yeast RNA and it also hydrolyzes polycytidylic and polyuridylic acids, but not polyadenylic, polyguanylic, and polyinosinic acids. The apparent molecular weight of the active enzyme is 28 500.
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PMID:Epidermal nucleases: purification and characterization of ribonuclease from mammalian epidermis. 23

Three enzyme reactions related to asparagine synthesis were studied in rat tissues: formation of aspartylhydroxamate, either from aspartate or by transfer from asparagine, and actual synthesis of asparagine from aspartate. Actual asparagine synthesis occurred at one-thousandth the rate of the other two reactions. Optimal conditions for quantitative assay of asparagine synthesis were determined in fetal liver extract, which is a rich source of the enzyme. Demonstrable activity in liver fell 6 days after birth to 20% of the fetal value and decreased slowly thereafter to the low adult value. Adult pancreas was the most active tissue found. The asparagine synthetase of fetal liver extracts was significantly inhibited when combined with adult liver or tumor extracts. The inhibitor fractionated with ammonium sulfate in close association with the asparagine synthetase. Therefore, demonstrable activities of asparagine synthetase in tissue extracts, measured in the presence of this inhibitor, do not necessarily parallel the concentrations of the enzyme present.
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PMID:Glutamine-dependent asparagine synthetase in fetal, adult and neoplastic rat tissues. 23 54

The IMP-cyclohydrolase/transformylase enzyme was purified from Ehrlich ascites tumor cells by ammonium sulfate fractionation and chromatography on Sephadex G-75 and DEAE-Sephadex. The electrophoretically pure enzyme has a molecular weight of about 350000, estimated by a gel filtration, and an isoelectric point of 6.2. It is composed of 8 subunits with a molecular weight of 46000. Every subunit is composed of two different proteins with a molecular weight of 18000 and 28500. Some further characteristics of the enzyme are reported.
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PMID:[IMP-cyclohydrolase/transformylase from ehrlich-ascites carcinoma (author's transl)]. 24 92

Formation of ribothymidine by the ribose exchange reaction between thymine and uridine with the cell-free extract of mouse Ehrlich ascites tumor cells was demonstrated. Since phosphate ions appear to be not required for this reaction, perhaps it proceeds by the mechnism of direct exchange of nucleoside N-ribosyltransferase. The transfer activity was found in the precipitates when the crude extract was fractionated with 30-60% saturated ammonium sulfate. Ribothymidine formation was also demonstrated between thymine and ribonucleosides other than uridine with this tumor extract. Production of ribothymidine from thymine and uridine was detected also by the use of extracts from lung, brain, and regenerating liver of normal rats, and from newborn rats (whole body). An extract of Rhodamine sarcoma exhibited the ribose exchange activity, while that of human gastric cancer did not.
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PMID:Formation of ribothymidine from thymine and ribonucleosides by the cell-free extract of tumors and rat tissues. 34 Apr 51

The effect of 60-F, a fraction obtained by 0.5 approximately 0.6 saturation of ammonium sulfate of streptomycin-pretreated cell-free extract from live hemolytic streptococci (avirulent Su strain), on release of 51Cr from the 51Cr-labeled Ehrlich ascites carcinoma cells was studied with following results: a) 60-F was found to be highly effective in releasing 51Cr from 51Cr-labeled Ehrlich ascites carcinoma cells. b) Additionally, destructive picutres of the tumor cells contacted with 60-F in vitro was observed by phase-contrast microscopic examination. c) Indication was that the 51Cr-releasing assay method is also useful for the study of the direct cytolytic effect of 60-F.
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PMID:Cytolytic action of 60-F derived from live hemolytic streptococci against Ehrlich carcinoma cells. 38 27

Yeast-form Candida albicans cells were disrupted for 1.5 min in a Braun homogenizer and centrifuged at 100,000 X g. The supernatant was concentrated by ammonium sulfate precipitation and then dialyzed. The resulting material (650 mg), containing 81.2% protein and 11.5% carbohydrate, was subjected to affinity chromatography on concanavalin A (Con A) linked to agarose. A protein fraction was eluted from the column with buffer, and a fraction containing mannan was eluted with 0.2 M alpha-methyl mannoside. The candidal soluble proteins had 19 components which were resolvable by polyacrylamide gel electrophoresis. The material with affinity for Con A contained mannan and 17% complexed protein. Antigenic differences between the soluble proteins and the mannan-protein complex were shown by lines of intersection in immunodiffusion. The soluble proteins devoid of mannan reacted in immunoelectrophoresis with sera from infected rabbits and patients with chronic candidiasis. These same sera also reacted with a mannan-protein complex eluted from the Con A column with alpha-methyl mannoside. The comparative ability of candidal proteins and cell wall-derived mannan to elicit skin test reactions in guinea pigs sensitized by infection or with formaldehyde-killed yeast was studied. Candidal proteins at a 10-mug dose elicited positive reactions at 6 and 21 days after sensitization. The reactions persisted for 48 h and showed minimal tendency to an arthus response, which was marked when mannan-containing antigens were used. The antigenicity of cell wall-derived mannans and candidal soluble proteins devoid of mannan was compared in immunodiffusion tests of sera from 39 patients with neoplastic disease. Of these patients with documented candidiasis, 13 of 20 reacted to one or more mannan antigens, and 3 of 20 reacted to candidal soluble proteins. In contrast, of those patients who were uninfected or had superficial Candida spp. infections, 5 of 19 reacted to candidal soluble proteins, and 16 of 19 reacted to one or more mannan antigens.
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PMID:Comparative serological and cutaneous reactivity of candidal cytoplasmic proteins and mannan separated by affinity for concanavalin A. 40 33

The size of androgen receptors from rat ventral and dorsal prostate, dorsal prostate (Dunning) tumor, testis, epididymis, and seminal vesicle was determined using Sephadex G-200 chromatogrpahy and sucrose gradient centrifugation. The protease inhibitor diisopropyl fluorophosphate (DFP) was used to minimize receptor breakdown. An 8-9 S, 85 to 106 A receptor (Mr = 280,000 to 365,000; f/fo = 1.9 to 2.4) observed in unfractionated cytosol prepared in low ionic strength buffer with or without DFP is in equilibrium with a 4.5-5 S, 58 A form (Mr = 117,000; f/fo = 1.8) observed at salt concentrations greater than 0.1 M KCl. Receptor partially purified using (NH4)2SO4 or phosphocellulose chromatography in the absence of DFP was present as smaller fragments of 3.6 S, 37 A and 3.0 S, 23 A. Similar fragments could be generated from the 4.5 S or 8 S receptor by mild trypsin treatment. In addition, ventral prostate contains a DFP-insensitive enzyme which specifically converts the 4.5 S, 58 A receptor to the 3.6 S 37 A fragment. The DFP-insensitive enzyme is partially inhibited by rabbit bile and appears similar to the enzyme seminin, a secretory protein of human prostate. Androgen receptor isolated in the presence of DFP from nuclei labeled in vivo is predominantly 4.5 S, 58 A, with smaller forms (37 and 23 A) appearing in the absence of DFP. The 4.5 S, 58 A nuclear receptors were also in equilibrium with a large 8 S form. Receptor breakdown by DFP-insensitive and sensitive proteases appears to be an in vitro phenomenon. Furthermore, the size of the androgen receptor is not significantly changed during receptor migration from cytoplasm to nucleus.
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PMID:Effects of proteases and protease inhibitors on the 4.5 S and 8 S androgen receptor. 44 15

Interferon production was induced in mouse Ehrlich ascites tumor cells by infection with Newcastle disease virus. The interferon produced was purified by precipitation with ammonium sulfate, chromatography on carboxymethyl-Sephadex, treatment with blue dextran and polyethylene glycol, gel filtration on Bio-Gel P-60 and Bio-Gel P-200, chromatography on phosphocellulose, isoelectric focusing, and chromatography on octyl-Sepharose. The specific activity of the product was 1.6 x 10(9) NIH mouse interferon reference standard units/mg of protein. Electrophoresis in polyacrylamide gels in the presence of sodium dodecyl sulfate indicated that the apparent molecular weight of the interferon-active material ranged from 25,000 to 35,000. As revealed by staining the gels with Coomassie brilliant blue, the interferon activity co-migrated with the major, broad protein band. Minor, stainable bands of proteins were free of interferon activity and their apparent molecular weight was smaller than 12,000.
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PMID:Purification of interferon from mouse Ehrlich ascites tumor cells. 56


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