Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The method employed to determine the sequence of a T1 RNase fragment, A-A-A-A-A-U-A-A-C-A-A-U-A-C-A-Gp, from Novikoff rat hepatoma 18S ribosomal RNA is described. This method is applicable to any oligoribonucleotide produced by specific endonucleases that leave the newly cleaved 5'-end free for labeling with polynucleotide kinase and gamma-(32p)-ATP. The (32p)-labeled oligoribonucleotide is subjected to partial endonucleolytic digestion and fractionated by two-dimensional homochromatography fingerprinting. The nucleotide sequence is determined by following mobility shifts of the labeled and partially digested oligoribonucleotides in homochromatography fingerprinting.
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PMID:Sequence analysis of T1 ribonuclease fragments of 18S ribosomal RNA by 5'-terminal labeling, partial digestion, and homochromatography fingerprinting. 19 May 90

U3A, U3B, and U3C are three distinct molecular weight nucleolar RNAs present in Novikoff hepatoma ascites cells. The primary nucleotide sequence of U3B, the most prominent of these U3 species, was determined. Purified U3B RNA was subjected to various enzymatic digestion procedures, including digests of 32P-labeled U3B RNA, RNA ligase, and polynucleotide kinase labeling, for determination of its primary sequence which is: (formula: see text). The 5'-terminus of the RNA has a "cap" and localized purine-rich regions were found near the 3'-terminus, which have been incorporated into a hydrogen-bonded region in a proposed secondary structure of the molecule.
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PMID:Nucleotide sequence of nucleolar U3B RNA. 50 Jun 26

We have detected the in situ activities of DNA glycosylase, endonuclease, exonuclease, DNA polymerase, and DNA ligase using a novel polyacrylamide activity gel electrophoresis procedure. DNA metabolizing enzymes were resolved through either native or SDS-polyacrylamide gels containing defined 32P-labeled oligonucleotides annealed to M13 DNA. After electrophoresis, these enzymes catalyzed in situ reactions and their [32P]DNA products were resolved from the gel by a second dimension of electrophoresis through a denaturing DNA sequencing gel. Detection of modified (degraded or elongated) oligonucleotide chains was used to locate various enzyme activities. The catalytic and physical properties of Novikoff hepatoma DNA polymerase beta were found to be similar under both in vitro and in situ conditions. With 3'-terminally matched and mismatched [32P]DNA substrates in the same activity gel, DNA polymerase and/or 3' to 5' exonuclease activities of Escherichia coli DNA polymerase I (large fragment), DNA polymerase III (holoenzyme), and exonuclease III were detected and characterized. In addition, use of matched and mismatched DNA primers permitted the uncoupling of mismatch excision and chain extension steps. Activities first detected in nondenaturing activity gels as either multifunctional or multimeric enzymes were also identified in denaturing activity gels, and assignment of activities to specific polypeptides suggested subunit composition. Furthermore, DNA substrates cast within polyacrylamide gels were successfully modified by the exogenous enzymes polynucleotide kinase and alkaline phosphatase before and after in situ detection of E. coli DNA ligase activity, respectively. Several restriction endonucleases and the tripeptide (Lys-Trp-Lys), which acts as an apurinic/apyrimidinic endonuclease, were able to diffuse into gels and modify DNA. This ability to create intermediate substrates within activity gels could prove extremely useful in delineating the steps of DNA replication and repair pathways.
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PMID:Characterization of DNA metabolizing enzymes in situ following polyacrylamide gel electrophoresis. 200 53

DNA-dependent ATPase IV has been purified to near homogeneity from the Novikoff rat hepatoma. The enzyme is devoid of DNA polymerase, RNA polymerase, exonuclease, endonuclease, phosphomonoesterase, 3'- or 5'-phosphodiesterase, polynucleotide kinase, protein kinase, topoisomerase, helicase or DNA reannealing activities at a detection level of 10(-5) to 10(-7) relative to the ATPase activity. The enzyme is a monomer of Mr 110,000, has a sedimentation coefficient of 5.9 S, a Stokes radius of 40 A and a frictional coefficient of 1.32. In the presence of Mg2+ ion and a polynucleotide effector, ATPase IV hydrolyzes either ATP or dATP to the nucleoside diphosphate plus Pi. Other ribo- or deoxyribonucleoside triphosphates are not substrates. ATPase IV utilizes double-stranded DNA and single-stranded DNA as effector; however, it does not utilize poly(dT). The Km for dsDNA or ssDNA is 2.2 microM (nucleotide). A variety of ATP analogues were found to be competitive inhibitors of ATPase IV.
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PMID:Purification and enzymological characterization of DNA-dependent ATPase IV from the Novikoff hepatoma. 296 5

DNA-RNA hybridization studies, using nuclear RNA's (nRNA's) labeled in vivo and in vitro with high specific radioactivities, were performed to compare the nRNA populations of normal rat liver, livers treated with 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB), and 3'-Me-DAB-induced hepatomas. The study with normal liver nRNA labeled by i.p. injection of [3H]orotic acid indicated that the nuclei of a 3'-Me-DAB-induced transplanted hepatoma, AH136B, lacked some RNA species present in normal liver nuclei. No qualitative difference in thee RNA populations was seen between normal liver and the livers of rats fed a carcinogenic amount of 3'-Me-DAB, either alone or in combination with 4-nitrostilbene which enhanced the azo dye carcinogenesis. Then, nRNA's of both normal liver and AH136B hepatoma were labeled in vitro by phosphorylation with polynucleotide kinase and adenosine 5'-[gamma-32P]triphosphate. The competitive hybridization with 32P-labeled normal liver nRNA was competed, and the deletion of RNA in the nuclei of AH136B hepatoma or 3'-Me-DAB-induced primary hepatoma was estimated to be 15% or more in the measure of radioactivity of the hybridized normal liver nRNA. 32P-labeled AH136B hepatoma nRNA was completed completely by liver nRNA's, suggesting that no unique RNA species were present in the hepatoma nuclei.
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PMID:Analysis of loss of nuclear RNA in azo dye-induced hepatoma by DNA-RNA competitive hybridization. 705 6