| Interaction of normal and tumor transfer RNA methyltransferases with ethionine-induced methyl-deficient rat liver transfer RNA. | |
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MedLine Citation:
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PMID: 171059 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The tRNA methyltransferases from normal rat liver and Novikoff hepatoma have been compared with respect to their base specificity, capacity to methylate, and reaction kinetics, using mixed Escherichia coli B transfer RNA (tRNA) and ethionine-induced partially methyl-deficient rat liver tRNA. The pattern of base methylation of the two substrates is different with the use of enzymes from either source. In particular, N1-methylguanine methylation is much greater in the methyl-deficient rat liver tRNA. The enzymes from the two sources also show differences in specificity of base methylation in either substrate, particularly in the percentage of N2-methylguanine synthesized. The Novikoff hepatoma enzymes have a greater capacity for methylation with either type of tRNA than do rat liver enzymes. The methyl-deficient rat liver tRNA is a poorer substrate for the enzymes from both sources than is E. coli B tRNA in terms of rate of methylation as well as total acceptance of methyl groups. The affinity constants are somewhat higher for the methyl-deficient rat liver tRNA than for E. coli B tRNA. The Novikoff hepatoma enzymes, in general, have larger affinity constants than the rat liver enzymes. Maximal velocities for the various base-specific enzymes are lower with the methyl-deficient rat liver tRNA, with the exception of the 1-methylguanine specific enzymes. These enzymes from either rat liver or Novikoff hepatoma exhibit approximately a 2.5-fold greater maximal velocity with methyl-deficient rat liver tRNA. |
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Authors:
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S J Kerr |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Cancer research Volume: 35 ISSN: 0008-5472 ISO Abbreviation: Cancer Res. Publication Date: 1975 Nov |
Date Detail:
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Created Date: 1976-01-10 Completed Date: 1976-01-10 Revised Date: 2009-11-03 |
Medline Journal Info:
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Nlm Unique ID: 2984705R Medline TA: Cancer Res Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2969-73 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Carcinoma, Hepatocellular / enzymology* Escherichia coli / enzymology Ethionine / pharmacology Female Kinetics Liver / enzymology Liver Neoplasms / enzymology* Methylation Neoplasms, Experimental / enzymology RNA, Neoplasm* RNA, Transfer* Rats tRNA Methyltransferases / metabolism* |
| Chemical | |
Reg. No./Substance:
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0/RNA, Neoplasm; 13073-35-3/Ethionine; 9014-25-9/RNA, Transfer; EC 2.1.1.-/tRNA Methyltransferases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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