The influence of some alkylating agents on the structure of DNA in vitro

The influence of the industrially used mutagenic agents β-propiolactone (BPL), propylene oxide (PO) and butylene oxide (BO) on the structure of DNA in vitro was studied. The heat denaturation of DNA and its reversibility were used as a criterion of the structural change in the DNA molecule. The rate constants for the reaction of the different compounds with DNA were determined. The effects were correlated with the degree of alkylation. Butylene oxide and propylene oxide caused a decrease of the reversibility of the heat denaturation at a degree of alkylation at which the melting temperature was only slightly decreased. β-propiolactone had no influence on the reversibility, but decreased the melting temperature of DNA as a function of the degree of alkylation.