In vivo assay for somatic point mutations induced by genotoxic carcinogens: incorporation of [\(^{35}\)S]methionine into a rat liver cytochrome b\(_5\) normally lacking sulphur-containing amino acids
Please always quote using this URN: urn:nbn:de:bvb:20-opus-61047
- The trypsin fragments of rat liver microsomal cytochron1e b\(_5\) (Tb\(_5\)) lack both methionine (met) and cysteine (cys), i.e., the sulphur-containing antino acids. Tb\(_5\) should therefore contain no 358-radioactivity after isolation from animals treated wHh [\(^{35}\)S]met or [\(^{36}\)S]cys. If, however, the nucleic acids coding for this polypeptide have been damaged by a genotoxic carcinogen, a miscoding could result in an incorporation of met or cys into the polypeptide so that Tb\(_8\) could now be \(^{36}\)S-radiolabelled. TwoThe trypsin fragments of rat liver microsomal cytochron1e b\(_5\) (Tb\(_5\)) lack both methionine (met) and cysteine (cys), i.e., the sulphur-containing antino acids. Tb\(_5\) should therefore contain no 358-radioactivity after isolation from animals treated wHh [\(^{35}\)S]met or [\(^{36}\)S]cys. If, however, the nucleic acids coding for this polypeptide have been damaged by a genotoxic carcinogen, a miscoding could result in an incorporation of met or cys into the polypeptide so that Tb\(_8\) could now be \(^{36}\)S-radiolabelled. Two experiments are descrihed. the first one where a toxic regimen of N -nitrosomorpholine (NNM) to rats resulted in a significant increase of \(^{35}\)S-radioactivity in the Tbs of liver microsomes, and a second experiment with a non-toxic regimen of N,N diethylnitrosamine (DENA), where no increase was observable.…
Author: | A. Jauch, Werner K. Lutz |
---|---|
URN: | urn:nbn:de:bvb:20-opus-61047 |
Document Type: | Journal article |
Faculties: | Medizinische Fakultät / Institut für Pharmakologie und Toxikologie |
Language: | English |
Year of Completion: | 1983 |
Source: | Chemico-Biological Interactions (1983) 46, 2, 139-49. |
Dewey Decimal Classification: | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |
GND Keyword: | Toxikologie |
Tag: | Amino acid composition; Cytochrome b5; MammaJian mutagenicity test; Pointmutation; Protein coding; Rat Iiver microsomes |
Release Date: | 2012/01/25 |
Licence (German): | Deutsches Urheberrecht |