Figure 2–82. Basic skeleton in the molecules of N-nitrosocontaining supermutagens (A) and the radical of Gordy and co-authors (B) determined by EPR-spectroscopy.
According to Bostock and Sumner (1981) it is undoubtedly proven
that in mammals chromosome damages arise as a result of the action of
radioactive irradiations on proteins. They give reasons for their opinion on
the basis of the results of other authors showing that in the cells of
chinese hamster the lethal effect and chromosome aberrations are
caused by irradiations, whose specter is different from the absorption
specter of DNA (Chu. 1965; Rauth. 1970) and resemble that of tyrosine
containing proteins (Zirkle. Uretz. 1963).
Figure 2–83. Diagram illustrating intercalation of acridine dyes in DNA-molecule (After L. S. Lerman, 1964; From Bostock and Sumner, 1981).
Some chemical compounds play the role of mutagens. without causing direct
damages in DNA. These are so-called intercalated agents. Among them.
proflavin, acriflavin, and acridine orange are better studied.
Lerman (1961. 1963) has shown that acridinic dyes form complexes with DNA. At
that their planar molecules penetrate (intercalate) between neighbouring
nucleotide bases, which leads to increasing the distance between them (Fig. 2–83). It is
supposed that acridine molecules, after eir interaction with DNA, induce incorrect
complementation of the nucleotide bases and mutations with shifting the frame of reading.