Differential Sensitivity to Certain DNA-Damaging Treatments, Including 8-Methoxypsoralen Plus 340 nm Ultraviolet Irradiation, Between K-12 and B/r Strains of Escherichia Coli
For want of information to the contrary, it is usually assumed that when a molecule of a mutagen is near to a molecule of DNA, reaction will occur with a probability that is essentially the same whether or not the DNA is in a bacterial or human chromosome, whether or not it is complexed with proteins, and whatever its degree of superhelicity. A moment’s thought suggests that this assumption is unlikely to be strictly true although it would be a bold man who would predict to what extent chromosomal structure might influence the probability of interaction with mutagens. The present paper records a simple bacterial model where the simplest interpretation of the data suggests that the structure rather than sequence of the DNA seems to affect the probability of interaction with intercalating agents such as 8-methoxypsoralen (8-MOP).
KeywordsDifferential Sensitivity Intercalate Agent Methane Sulphonate Methyl Methane Sulphonate Toluene Base Scintillation
Unable to display preview. Download preview PDF.
- 7.Hubbard, S. A., Green, M. H. L., Bridges, B. A., Wain, A. J. and Bridges, J. W.: The fluctuation test with S9 and hepatocyte activation, in Short Term Tests for Carcinogens ( Report of the International Collaborative Programme) Plenum Press, New York (1981).Google Scholar
- 8.Toogood, S. M.: The role of metabolism in some short term tests for chemical carcinogens and mutagens, M. Phil. Thesis, University of York (1979)Google Scholar
- 10.Davies, B. D. and Mingioli, E. S.: Mutants of Escherichia coZi requiring methionine or vitamin B12. J. Bacteriol., 60: 17 (1950)Google Scholar
- 11.Bridges, B. A., Mottershead, R. P. and Knowles, A.: Mutation induction and killing of Escherichia coZi by DNA adducts and crosslinks: a photobiological study with 8-methoxypsoralen. Chem.-Biol. Interactions, 27: 221 (1979)Google Scholar