title: [Lethal effect after transmutation of 33P incorporated into bacteriophage S 13 and mechanisms of DNA double helix rupture].
abstract: The experiments show the lethal effect of the beta decay of 33P incorporated in DNA of bacteriophage S 13. The lethal efficiency is high, 0.72 at 0 degrees C and 0.55 at--197 degrees C. The presence of a radical scavenger like AET has no influence. It was found previously that for such phages with single-stranded DNA, the lethal efficiency of 32P decay is unity, and that the lethal event is a DNA single-strand break, owing to the high energy of the nucleogenic 32S atom. As the recoil energy of the 33S atom is too low to account for such a break, it is suggested that the reorganization of the phosphate molecule into sulphate is able to bring about a DNA single-strand break with an efficiency as high as 0.7, at 0 degrees C. A model for the DNA double-strand-break produced by a transmutation processes is suggested.
mesh_terms: D001435:Bacteriophages / Q000378:metabolism / Q000528:radiation effects*; D004277:DNA, Single-Stranded / Q000528:radiation effects; D004279:DNA, Viral / Q000528:radiation effects*; D004583:Electrons; D004926:Escherichia coli; D008954:Models, Biological; D010710:Phosphates / Q000378:metabolism / Q000528:radiation effects; D010761:Phosphorus Radioisotopes; D011839:Radiation, Ionizing; D011851:Radioactivity; D013431:Sulfates / Q000378:metabolism / Q000528:radiation effects; D013696:Temperature
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D010710:Phosphates; D010761:Phosphorus Radioisotopes; D013431:Sulfates
vernacular_title: Effet létal de la transmutation de 33P incorporé dans le bactériophage S 13 et mécanisme de rupture de la double hélice de l'ADN.