The binding of dimethylnitrosamine to nucleic acids catalyzed by liver enzymic fractions

The in vitro binding of a metabolite of dimethylnitrosamine (DMNA) to calf thymus DNA catalyzed by a microsomal system from rat liver is reported. The amount ob binding is unaffected by using microsomes induced by 3-methylcholanthrene and/or normal or induced pH 5 enzymes. The microsomal system is also effective in catalyzing covalent binding of the nitroso compound with synthetic polyribonucleotides.