Evidence for the mutagenic potential of the vinyl chloride induced added, N2, 3-etheno-deoxyguanosine, using a site-directed kinetic assay
| Autor: | J.T. Kuśmierek, Brett C. Singer, M.K. Dosanjh, W. Folkman, F. Chavez |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Cancer Research
Guanine Polynucleotide 5'-Hydroxyl-Kinase Base pair Vinyl Chloride chemistry.chemical_compound Chloroacetaldehyde Chromatography High Pressure Liquid Polymerase Klenow fragment Base Composition Guanosine biology Oligonucleotide Deoxyguanine Nucleotides DNA General Medicine Kinetics chemistry Biochemistry biology.protein Primer (molecular biology) DNA polymerase I Phosphorus Radioisotopes Mutagens Thymidine |
| Zdroj: | Carcinogenesis. 12:745-747 |
| ISSN: | 1460-2180 0143-3334 |
| DOI: | 10.1093/carcin/12.4.745 |
| Popis: | N2,3-Ethenoguanine (epsilon G) is a product of vinyl chloride reaction with DNA in vivo and of its ultimate metabolite, chloroacetaldehyde, in vitro. The synthesis of the very labile 5'-triphosphate of N2,3-etheno-deoxyguanosine (epsilon dGuo) has made it possible to study the base pairing properties of this derivative placed opposite a defined normal base in a 25-base oligonucleotide template. The kinetic parameters, Km and Vmax were determined from elongation of a [32P]5'-end labeled primer annealed one base prior to the designated template base, epsilon G.T pairs, which would be mutagenic, were formed with a frequency 2- to 4-fold greater than the analogous wobble pair, G.T. The non-mutagenic pairing, epsilon G.C, occurs with a lower frequency than G.C but neither epsilon G.T or epsilon G.C constitute a significant block to replication. The frequency of epsilon G.T formation was similar with all polymerases tested: Escherichia coli DNA polymerase I (Klenow fragment), exonuclease-free Klenow, Drosophila melanogaster polymerase alpha-primase complex and human immunodeficient virus-I reverse transcriptase (HIV-RT). It is concluded that these prokaryotic and eukaryotic replicating enzymes apparently recognize the same structural features, and on replication G----A transitions would occur, which in turn, could initiate malignant transformation. In contrast to the G.T mismatch which is known to have a specific repair system, etheno derivatives are apparently not repaired in vivo. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|