[Effect of adenine, adenosine and adenylic nucleotides on the mutagenic effect of hydroxylamine].

The effect of some adenyl precursors of DNA synthesis on the mutagenic activity of hydroxylamine (HA) is studied. It is shown that the addition of adenine to a suspension of Escherichia coli B cells increases the yield of mutants by more than two times as compared with HA alone. The effects of adenosine, AMP and dAMP are somewhat different. It is suggested that the increase of the HA mutagenic effect produced by the addition of adenine may be due to: 1) the excess of the amount of adenylic precursors of DNA synthesis over guanilic ones, which promotes the erroneous base-pairing during the replication of the HA modified template; 2) the modification of adenylic precursors by HA into N6-oxy-dATP, and their incorporation into DNA. The mutagenic effect of N6-hydroxyadenosine, the product of the adenine modification by HA, in E. coli B pur- was studied. The experiments showed that N6-hydroxyadenosine induced about 1% of mutations, a relatively low lethal effect (the cell survival was 80%), and provided a high mutagenic action of this compound.